Building a diesel powered RHD TJ Wrangler (Picture Heavy)

[RustyAutoholicGuy]

Pretty incredible how efficient those little diesels can be in the TJs.

Yeah that was my thought as well, if I had the correct gearing in my axles, I think my in-town would be closer to 25 ~ 27 mpg honestly. I know Jeep had a 2.5l VM Motori engine that they installed in international XJ Cherokees after the face lift in 1996, that would have been a FANTASTIC combination in a TJ Wrangler. For reference that combination came with either the AX-15 or AW4 from what I have researched.

 

[Rickyd]

Yeah that was my thought as well, if I had the correct gearing in my axles, I think my in-town would be closer to 25 ~ 27 mpg honestly. I know Jeep had a 2.5l VM Motori engine that they installed in international XJ Cherokees after the face lift in 1996, that would have been a FANTASTIC combination in a TJ Wrangler. For reference that combination came with either the AX-15 or AW4 from what I have researched.

What gearing do you think would be suitable? What tires are you running?

 

[RustyAutoholicGuy]

What gearing do you think would be suitable? What tires are you running?

Currently running 235/85r16 tires which is a 31.7 tall tire, though I'm considering going to a 33x10.5r15 at some point. My current gearing is 3.73. I have a set of Rubicon axles that would put my at 4.10 gears, but truthfully I could even go 5.13, which would shift my 55mph cruise from 3rd gear to 4th gear. I've put enough miles on this TDI to realize at highway speeds it likes to cruise above 2200rpm.

Thanks
Grant

 

[XCRN]

I have been reading this a lot and I love all the thorough technical engineering stuff you have posted on this and I think I am now wanting to do a TDI with an auto to my LJ. I was thinking of doing a BHW but I am in the end, I am setting the baseline acceleration comparable to a 4.0. Do you think the acceleration of the BEW is close or better than a 4.0? I plan on doing a lot of highway driving with it and I was planning on 33s like you said you plan on going and I just need to make sure I can keep up with highway speeds and I plan on towing a small camper. Again this is an awesome build and very well documented!

 

[RustyAutoholicGuy]

I have been reading this a lot and I love all the thorough technical engineering stuff you have posted on this and I think I am now wanting to do a TDI with an auto to my LJ. I was thinking of doing a BHW but I am in the end, I am setting the baseline acceleration comparable to a 4.0. Do you think the acceleration of the BEW is close or better than a 4.0? I plan on doing a lot of highway driving with it and I was planning on 33s like you said you plan on going and I just need to make sure I can keep up with highway speeds and I plan on towing a small camper. Again this is an awesome build and very well documented!

So first off, with a simple tune and a better turbo, like the GTD1752 or even the GTD1756, in terms of accelerations, the BEW TDI is significantly faster than the 4.0l, even a manual 4.0l vs my automatic TDI. This 1.9l is deceptively quick, and the fuel economy is amazing as well. Also the BHW and BEW are both VERY similar and comparable, I would say just get whichever swap vehicle you can for the cheapest price possible.

I have the GTD1752, but the rest of my BEW TDI is stock, though I have a massive intercooler. I specially had my tune designed for fuel economy and low EGTs, up until this point heat has been my biggest enemy on this swap. Now this numbers are estimated and not verified with a dyno, but my tuner has told me my ballpark horsepower should be around 170 ~ 180 hp and my torque should be anywhere from 300 ~ 325 ft/lbs of torque. That torque comes on peak at around 1900rpm vs the 4.0l doesn't hit peak torque until well after 3000rpm.

Gearing is going to be everything. It took me longer than I care to admit to learn that these TDIs are RPM happy. I'm use the 2.8l VM Motori in my Liberty CRD and the Eco Diesel in my Gladiator that like cruising RPM that is below 2000rpm. When I get this BEW TDI over 2200rpm above 45mph, it just cruises down the highway like it's nothing.

If you haven't decided on an Automatic yet, I would highly recommend the AW4 and swapping the valvebody from Toyota Tacoma so that you get rid of the TV Cable (Throttle Value) and let the CompuShift controller handle line pressure. I keep a close eye on transmission temperatures, the hottest I've seen mine are around 188° Fahrenheit. I honestly believe the reputation for the AW4 running hot comes from that TV cable. Part of this is because the TV cable present a linear increase to line pressure, the position of the throttle pedal dictates the amount of line pressure. Where as with the CompuShift and the new value body out of the Toyota Tacoma, line pressure is now based on throttle position, engine load, AND MAP (Mass Air Presssure) aka Turbo boost pressure.

Great example with my BEW TDI. If I'm cruising on flat ground at 45mph, I'm at anywhere between 5 ~ 8 psi of boost. When I get to a hill, I've seen that pressure climb up to around 18 ~ 20 psi, even though my engine RPM is the same. What the CompuShift does is see that boost pressure is increasing, even though RPM is the same, so it will increase line pressure to ensure the transmission doesn't slip which would cause heat.

The big thing here will be gearing, especially with the AW4. For 33, which if you are running BF Goodrich KO2 which are really 32.5, you either want 4.10 gears where your 55 ~ 65mph cruise speed would be in 3rd gear torque converter lock and anything over 70mph would be in 4th gear OR you want 5.13 gears, which would move your 55mph and high speeds directly to 4th gear torque converter lock.

I don't have an answer for that yet, I'm on 3.73 gears which is really not the right combination for my tires, engine and transmission currently and it will be something I will be addressing in the nearish future.

The last thing I will say, and this will be in my next update to this thread, use the factory style transmission mount with hydraulic motor mounts! I wish I had known that years ago, what a massive difference that has made on my TJ!

Let me know if you have any other questions!
-Grant

 

[Rickyd]

So first off, with a simple tune and a better turbo, like the GTD1752 or even the GTD1756, in terms of accelerations, the BEW TDI is significantly faster than the 4.0l, even a manual 4.0l vs my automatic TDI. This 1.9l is deceptively quick, and the fuel economy is amazing as well. Also the BHW and BEW are both VERY similar and comparable, I would say just get whichever swap vehicle you can for the cheapest price possible.

I have the GTD1752, but the rest of my BEW TDI is stock, though I have a massive intercooler. I specially had my tune designed for fuel economy and low EGTs, up until this point heat has been my biggest enemy on this swap. Now this numbers are estimated and not verified with a dyno, but my tuner has told me my ballpark horsepower should be around 170 ~ 180 hp and my torque should be anywhere from 300 ~ 325 ft/lbs of torque. That torque comes on peak at around 1900rpm vs the 4.0l doesn't hit peak torque until well after 3000rpm.

Gearing is going to be everything. It took me longer than I care to admit to learn that these TDIs are RPM happy. I'm use the 2.8l VM Motori in my Liberty CRD and the Eco Diesel in my Gladiator that like cruising RPM that is below 2000rpm. When I get this BEW TDI over 2200rpm above 45mph, it just cruises down the highway like it's nothing.

If you haven't decided on an Automatic yet, I would highly recommend the AW4 and swapping the valvebody from Toyota Tacoma so that you get rid of the TV Cable (Throttle Value) and let the CompuShift controller handle line pressure. I keep a close eye on transmission temperatures, the hottest I've seen mine are around 188° Fahrenheit. I honestly believe the reputation for the AW4 running hot comes from that TV cable. Part of this is because the TV cable present a linear increase to line pressure, the position of the throttle pedal dictates the amount of line pressure. Where as with the CompuShift and the new value body out of the Toyota Tacoma, line pressure is now based on throttle position, engine load, AND MAP (Mass Air Presssure) aka Turbo boost pressure.

Great example with my BEW TDI. If I'm cruising on flat ground at 45mph, I'm at anywhere between 5 ~ 8 psi of boost. When I get to a hill, I've seen that pressure climb up to around 18 ~ 20 psi, even though my engine RPM is the same. What the CompuShift does is see that boost pressure is increasing, even though RPM is the same, so it will increase line pressure to ensure the transmission doesn't slip which would cause heat.

The big thing here will be gearing, especially with the AW4. For 33, which if you are running BF Goodrich KO2 which are really 32.5, you either want 4.10 gears where your 55 ~ 65mph cruise speed would be in 3rd gear torque converter lock and anything over 70mph would be in 4th gear OR you want 5.13 gears, which would move your 55mph and high speeds directly to 4th gear torque converter lock.

I don't have an answer for that yet, I'm on 3.73 gears which is really not the right combination for my tires, engine and transmission currently and it will be something I will be addressing in the nearish future.

The last thing I will say, and this will be in my next update to this thread, use the factory style transmission mount with hydraulic motor mounts! I wish I had known that years ago, what a massive difference that has made on my TJ!

Let me know if you have any other questions!
-Grant

Have you done much research on how heavy is too heavy for the tdi?

They seem like a great little motor but i worry about lifespan in a tj like mine with a bunch of 1/4" armor

 

[RustyAutoholicGuy]

Have you done much research on how heavy is too heavy for the tdi?

They seem like a great little motor but i worry about lifespan in a tj like mine with a bunch of 1/4" armor

How heavy do you think your LJ weighs? I've seen guys running these TDIs in full armored XJs and Toyotas that are over 5000lbs, the key is proper gearing, for the transmission and axles. If you can keep the RPMs in the correct range I would think you would be fine. These little motors are surprisingly strong if geared properly.

 

[XCRN]

So first off, with a simple tune and a better turbo, like the GTD1752 or even the GTD1756, in terms of accelerations, the BEW TDI is significantly faster than the 4.0l, even a manual 4.0l vs my automatic TDI. This 1.9l is deceptively quick, and the fuel economy is amazing as well. Also the BHW and BEW are both VERY similar and comparable, I would say just get whichever swap vehicle you can for the cheapest price possible.

I have the GTD1752, but the rest of my BEW TDI is stock, though I have a massive intercooler. I specially had my tune designed for fuel economy and low EGTs, up until this point heat has been my biggest enemy on this swap. Now this numbers are estimated and not verified with a dyno, but my tuner has told me my ballpark horsepower should be around 170 ~ 180 hp and my torque should be anywhere from 300 ~ 325 ft/lbs of torque. That torque comes on peak at around 1900rpm vs the 4.0l doesn't hit peak torque until well after 3000rpm.

Gearing is going to be everything. It took me longer than I care to admit to learn that these TDIs are RPM happy. I'm use the 2.8l VM Motori in my Liberty CRD and the Eco Diesel in my Gladiator that like cruising RPM that is below 2000rpm. When I get this BEW TDI over 2200rpm above 45mph, it just cruises down the highway like it's nothing.

If you haven't decided on an Automatic yet, I would highly recommend the AW4 and swapping the valvebody from Toyota Tacoma so that you get rid of the TV Cable (Throttle Value) and let the CompuShift controller handle line pressure. I keep a close eye on transmission temperatures, the hottest I've seen mine are around 188° Fahrenheit. I honestly believe the reputation for the AW4 running hot comes from that TV cable. Part of this is because the TV cable present a linear increase to line pressure, the position of the throttle pedal dictates the amount of line pressure. Where as with the CompuShift and the new value body out of the Toyota Tacoma, line pressure is now based on throttle position, engine load, AND MAP (Mass Air Presssure) aka Turbo boost pressure.

Great example with my BEW TDI. If I'm cruising on flat ground at 45mph, I'm at anywhere between 5 ~ 8 psi of boost. When I get to a hill, I've seen that pressure climb up to around 18 ~ 20 psi, even though my engine RPM is the same. What the CompuShift does is see that boost pressure is increasing, even though RPM is the same, so it will increase line pressure to ensure the transmission doesn't slip which would cause heat.

The big thing here will be gearing, especially with the AW4. For 33, which if you are running BF Goodrich KO2 which are really 32.5, you either want 4.10 gears where your 55 ~ 65mph cruise speed would be in 3rd gear torque converter lock and anything over 70mph would be in 4th gear OR you want 5.13 gears, which would move your 55mph and high speeds directly to 4th gear torque converter lock.

I don't have an answer for that yet, I'm on 3.73 gears which is really not the right combination for my tires, engine and transmission currently and it will be something I will be addressing in the nearish future.

The last thing I will say, and this will be in my next update to this thread, use the factory style transmission mount with hydraulic motor mounts! I wish I had known that years ago, what a massive difference that has made on my TJ!

Let me know if you have any other questions!
-Grant

That is good to know on the acceleration, I really want to keep this reliable so I do not want to go too crazy with building and tuning, but enough to keep up on the highway and I figured the torque would be enough to get me where I want to go.

I got spoiled with the LS in the TJ where I did not have to put a huge emphasis on gearing for the axles. 3.73 is even too much, but I figured with a TDI going into the LJ I would have to pay attention. But yes I plan on going with an AW4 and I wanted to follow your lead on making a hybrind trans which seems like it was a simple enough swap to make happen. Was there a particular year of AW4 and A340 valvebody you preferred to run or did you just use what ever you could get your hands on? I was looking at the Compushift setup and it seems like there are many different options when specing out a kit for the trans. So I assume since it asks what engine you are running, it has some kind of CAN communication between the TDI and trans computer?

And I can agree with a factory trans mount for this. I noticed a huge difference in NVH going from some universal poly mount to a factory trans mount on my LS TJ. I eventually want to get some hydraulic engine isolators like from a C6 Corvette on there as well. But when I go TDI on the LJ, I definitely want to keep the smoother ride since this will be the adventure rig where I will be in it for hours so keeping the engine harmonics down would be a big priority. The LS TJ is fun, but it's not the best long road trip vehicle.

So I do have a question on your brake setup. Is there a reason you went with a hydroboost instead of an electric vacuum pump from a new ZR1 Corvette? I may have missed the reason reading through these pages so my apologies for bringing up a question that may have already been answered.

 

[RustyAutoholicGuy]

That is good to know on the acceleration, I really want to keep this reliable so I do not want to go too crazy with building and tuning, but enough to keep up on the highway and I figured the torque would be enough to get me where I want to go.

I got spoiled with the LS in the TJ where I did not have to put a huge emphasis on gearing for the axles. 3.73 is even too much, but I figured with a TDI going into the LJ I would have to pay attention. But yes I plan on going with an AW4 and I wanted to follow your lead on making a hybrind trans which seems like it was a simple enough swap to make happen. Was there a particular year of AW4 and A340 valvebody you preferred to run or did you just use what ever you could get your hands on? I was looking at the Compushift setup and it seems like there are many different options when specing out a kit for the trans. So I assume since it asks what engine you are running, it has some kind of CAN communication between the TDI and trans computer?

And I can agree with a factory trans mount for this. I noticed a huge difference in NVH going from some universal poly mount to a factory trans mount on my LS TJ. I eventually want to get some hydraulic engine isolators like from a C6 Corvette on there as well. But when I go TDI on the LJ, I definitely want to keep the smoother ride since this will be the adventure rig where I will be in it for hours so keeping the engine harmonics down would be a big priority. The LS TJ is fun, but it's not the best long road trip vehicle.

So I do have a question on your brake setup. Is there a reason you went with a hydroboost instead of an electric vacuum pump from a new ZR1 Corvette? I may have missed the reason reading through these pages so my apologies for bringing up a question that may have already been answered.

Honestly if I was more of a V engine guy, I would have gone 4.8l LS in my build, I just really like my inline engines and the low end torque of the diesel. I might have still gone AW4 with the LS as well, it's a surprisingly strong transmission if you address some of it's flaws, specifically the valve body for sure. I understand why some people don't like it, but it's been working very well for me so far.

As for which years for the AW4, I would get anything after about 1991 for AW4, just make sure it's a 23 spline output instead of a 21-spline output. The 23-spline output has an overdrive ratio of .75 where as the 21-spline output has a .705 overdrive, you want the .75 overdrive. For the A340 donor transmission, I went with a 2007 Toyota Tacoma 2.4l 4-cylinder 2wd drive transmission. I've found they are cheap because it's 2wd and not 4wd. Reference this video here for everything I did to get mine put together. The other I did use was the Toyota transmission pan, it's deeper and it puts the transmission dipstick on the opposite side of the exhaust as well.

As for the mounts, I think the best setup is the factory style AW4 transmission mount and hydraulic motor mounts on the TDI engine, that will help reduce the majority of your vibrations!

As for the brakes, I'm now using the factory Vacuum Brake Booster setup. I originally went with the Hydroboost Brake Booster when I was running the Kubota V2403 mechanic turbo diesel engine because there was no vacuum pump on the engine. The TDIs have a vacuum pump that is spun by the camshaft on the back of the head, I'd recommend you just use the factory stuff, it keeps the installations much cleaner and simpler!

Thanks
Grant

 

[RustyAutoholicGuy]

Hey TJers,

Ever since I got my TJ running with a diesel engine, be it the Kubota V2403 or my BEW TDI, I have had an issue with engine vibrations being transmitted through the chassis and into the cab of my Wrangler. The Kubota was considerably more severe than the TDI, but I thought that was just the nature of doing a diesel swap. I would have never imagined in a million years that going to the OEM-style transmission mount would solve all those chassis vibration issues.

Since I began installing a diesel engine into my TJ Wrangler, I have been using my own fabricated crossmember and bushing-style transmission mount to hold up the various transmissions I've used on this swap. I did this for multiple reasons, one was to have a flat bell pan and the second was to move the drivetrain forward since the TDI engine was so much shorter than the 4.0l engine. This had the benefit of giving me a very long rear driveshaft in my TJ. The third reason was I believed this bushing and sleeve design was better than the factory OEM-style transmission mount.

I went with this design, trying both a perpendicular and parallel setup, because over the years, I knew of so many other people using a similar design. The reasons ranged from ease of replacing the bushings to a stronger design, and handle more power and torque being applied to your driveline, be it the engine or transmission. I had decided that going to the bushing in a sleeve-style mount for my transmission would be a better setup for my Wrangler. Well, I was wrong!

A while ago I was talking to my friend David, who has a TDI Swapped XJ Cherokee with an AW4, and asked him randomly what transmission mount he was running in his XJ Cherokee. He mentioned that he was using the factory OEM-style transmission mount. It was a quick question and we went to talking about other things.

Well, I couldn't get that tidbit of information out of my head. I decided the other weekend to see if I could quickly modify my crossmember for my transmission to accept the OEM-style mount. I was initially surprised by how quickly I modified my crossmember to accept the OEM-style mount. The entire modification only took about 30 minutes, though that wasn't surprising seeing as the transmission mount I was using was designed for the AW4.

After reinstalling the modified crossmember back onto my AW4 in my Wrangler, I started my TJ Wrangler. I instantly knew this was going to change everything. The engine is quieter, and the vibrations have been reduced by about 90%. The tub and chassis vibrate less now in gear, meaning Reverse or Drive, than the tub and chassis used to vibrate in Park or Neutral with my previous transmission mount setup.

The surprises kept on coming though. The BEW TDI, which I have now put over 150 miles on since doing this modification, runs cooler, accelerates faster, revs faster, and seems to breathe better. It's almost as if I had some driveline bind with my old transmission mount that wasn't allowing the TDI engine and AW4 automatic transmission to move as freely as it needed. I don't have a better explanation for it. My TDI engine just seems better.

Here is the video if you'd like to watch:

Let me know what you think!
-Grant

 

[Coachgeo]

Hey TJers,

Ever since I got my TJ running with a diesel engine, be it the Kubota V2403 or my BEW TDI, I have had an issue with engine vibrations being transmitted through the chassis and into the cab of my Wrangler.....

View attachment 546275

Since I began installing a diesel engine into my TJ Wrangler, I have been using my own fabricated crossmember and bushing-style transmission mount to hold up... the various transmissions I've used on this swap.I believed this bushing and sleeve design was better than the factory OEM-style transmission mount.....


I went with this design, trying both a perpendicular and parallel setup, because over the years, I knew of so many other people using a similar design. ......decided that going to the bushing in a sleeve-style mount for my transmission would be a better setup for my Wrangler. Well, I was wrong!.....





After reinstalling the modified crossmember back onto my AW4 in my Wrangler, I started my TJ Wrangler. I instantly knew this was going to change everything. The engine is quieter, and the vibrations have been reduced by about 90%. The tub and chassis vibrate less now in gear, meaning Reverse or Drive, than the tub and chassis used to vibrate in Park or Neutral with my previous transmission mount setup.

The surprises kept on coming though. The BEW TDI, which I have now put over 150 miles on since doing this modification, runs cooler, accelerates faster, revs faster, and seems to breathe better. It's almost as if I had some driveline bind with my old transmission mount that wasn't allowing the TDI engine and AW4 automatic transmission to move as freely as it needed. I don't have a better explanation for it. My TDI engine just seems better.

Here is the video ....

Let me know what you think!
-Grant

sitting in my invisible mechanics arm chair I will say your probably correct on better performance and your reasoning correct too. The last iteration it appears your bushing ends were pointed fore and aft.... so pivot was in orientation with crankshaft allowing for easy rotation of engine. AKA you gave it a pivot point. So yeah when under power .... like a drag truck lifting of driver wheel from torque at take off* the engine would rotate some and tweak everything. So this tweak...... in your set up; limited only by the engine mounts, likely pretty freely was causing bind down the chain. Engine had to work harder to overcome it all.

Folk with the OM617 report that using the OEM MB engine mounts didn't work well cause the torque from twisting engine.... particularly in Low range first gear... would keep ripping the driver front engine mount rubber in half in short order. Far as a know everyone used OEM jGM trans mount so their limit there was the trans mount... unlike yours which was the engine mounts. When I bought mine. (pre converted) the driver side was ripped apart. Myself w/out welder- nor hands on know how to redo motor mounts. Stuck with new OEM mounts but filled the cavity with a not stifff, but it will help rubber.... mayyyybe 30 durometer? and will put a limit strap so engine on driver side can lift no more than??? Im thinking 1/4"???

When you had that bushing side to side ... it likely was just not enough meat of rubber to reduce the vibrations etc. that tiny cross member likely didnt spread the load well either.

PS... IMHO that is not enough BEEF in that cross member. It might even be tweaking. Think about it.... that small bar stock is replacing what the GM engineers spread out thru the whole Skid plate/pan and the broad spaced attachment to chassis. If they could have gone that small they would have.. Think of all the mula they would save in manufacturing and materials if they did. My arm chair engineer status red flags kinda go off looking at it. (Granted gotta background that includes movement science's though aimed at human movement not vehicle movement)


*

 

[RustyAutoholicGuy]

sitting in my invisible mechanics arm chair I will say your probably correct on better performance and your reasoning correct too. The last iteration it appears your bushing ends were pointed fore and aft.... so pivot was in orientation with crankshaft allowing for easy rotation of engine. AKA you gave it a pivot point. So yeah when under power .... like a drag truck lifting of driver wheel from torque at take off* the engine would rotate some and tweak everything. So this tweak...... in your set up; limited only by the engine mounts, likely pretty freely was causing bind down the chain. Engine had to work harder to overcome it all.

Folk with the OM617 report that using the OEM MB engine mounts didn't work well cause the torque from twisting engine.... particularly in Low range first gear... would keep ripping the driver front engine mount rubber in half in short order. Far as a know everyone used OEM jGM trans mount so their limit there was the trans mount... unlike yours which was the engine mounts. When I bought mine. (pre converted) the driver side was ripped apart. Myself w/out welder- nor hands on know how to redo motor mounts. Stuck with new OEM mounts but filled the cavity with a not stifff, but it will help rubber.... mayyyybe 30 durometer? and will put a limit strap so engine on driver side can lift no more than??? Im thinking 1/4"???

When you had that bushing side to side ... it likely was just not enough meat of rubber to reduce the vibrations etc. that tiny cross member likely didnt spread the load well either.

PS... IMHO that is not enough BEEF in that cross member. It might even be tweaking. Think about it.... that small bar stock is replacing what the GM engineers spread out thru the whole Skid plate/pan and the broad spaced attachment to chassis. If they could have gone that small they would have.. Think of all the mula they would save in manufacturing and materials if they did. My arm chair engineer status red flags kinda go off looking at it. (Granted gotta background that includes movement science's though aimed at human movement not vehicle movement)


*

I agree with you on the the engine mounts and the small amount of rubber as well causing limited moment creating the bind.

As for the crossmember diameter, the video and photos don't do it justice. The diameter of that bar is bigger than the photos make it look and the wall thickness on that bar is massive as well. I was trying to go through my notes to find the exact specs on the diameter and wall thickness again but I can't find it. I did ask several people that I trust that do fabrication and work in machine shops if this bar would be strong enough for my application before committing to it.

Thanks
Grant

 

[Coachgeo]

I agree with you on the the engine mounts and the small amount of rubber as well causing limited moment creating the bind.

As for the crossmember diameter, the video and photos don't do it justice. The diameter of that bar is bigger than the photos make it look and the wall thickness on that bar is massive as well. I was trying to go through my notes to find the exact specs on the diameter and wall thickness again but I can't find it. I did ask several people that I trust that do fabrication and work in machine shops if this bar would be strong enough for my application before committing to it.

Thanks
Grant

Did ya'll also discuss the forces load spread at attachment to chassis too? Design your using has the spread of the forces in a pretty small area of 8-10? inches comparatively to the OEM of couple feet of spread along chassis rail.

 

[RustyAutoholicGuy]

Did ya'll also discuss the forces load spread at attachment to chassis too? Design your using has the spread of the forces in a pretty small area of 8-10? inches comparatively to the OEM of couple feet of spread along chassis rail.

Yes I did and it was based on other crossmember designed that are available from companies like GenRight as well:

https://genright.com/shop-by-vehicl...train/universal-transmission-crossmember-kit/

My design was based off of this roughly. I've been running this design for years now and with a heavier transmission as well. The Ford 6r80 I was running weighed 234lbs and I never had an issues with this setup. The AW4 is around 100lbs lighter which will help as well. It is something I will be keeping a close eye on but everything points to this being more than strong enough for my setup.

Thanks
Grant

 

[Coachgeo]

Yes I did and it was based on other crossmember designed that are available from companies like GenRight as well:

https://genright.com/shop-by-vehicl...train/universal-transmission-crossmember-kit/

View attachment 546300

My design was based off of this roughly. I've been running this design for years now and with a heavier transmission as well. The Ford 6r80 I was running weighed 234lbs and I never had an issues with this setup. The AW4 is around 100lbs lighter which will help as well. It is something I will be keeping a close eye on but everything points to this being more than strong enough for my setup.

Thanks
Grant

looks like their's has two mounts. One using kit above... and another one at back of T-case. Guess you are running two of them as well. If so then red flags go down LOL

 

[XCRN]

Im starting to get more serious about the TDI swap on my LJ and definitly leaning towards the AW4/A340 hybrid. I plan on rebuilding both engine and trans, but if you had to do anything internal to the transmission, would you do anything beyond the basic rebuild? Do you think the stock clutches can handle the instant torque or would looking at upgraded clutches be a good idea? Still trying to find the right deal on a BHW or BEW. Lots of BRMs but it sounds like they are not as swap friendly and no real cruise control options.

 

[RustyAutoholicGuy]

Im starting to get more serious about the TDI swap on my LJ and definitly leaning towards the AW4/A340 hybrid. I plan on rebuilding both engine and trans, but if you had to do anything internal to the transmission, would you do anything beyond the basic rebuild? Do you think the stock clutches can handle the instant torque or would looking at upgraded clutches be a good idea? Still trying to find the right deal on a BHW or BEW. Lots of BRMs but it sounds like they are not as swap friendly and no real cruise control options.

It all comes down to the power you are trying to make. I know I'm roughly 160hp and 285 ~ 300 ft/lbs of torque on my tune. With that power I wouldn't really worry about the anything big in the transmission. While you have a ton of torque with this BEW TDI, but you aren't going to get into big torque numbers until full boost. What makes this package so nice is the CompuShift controlling line pressure on the AW4 via information coming from the VW ECU over CANBUS. The CompuShift will increase the line pressure based on a slew of variables, RPM, Engine Load, and Mass Air Pressure (Boost Pressure). Having that clamping force from the line pressure really does make a huge difference.

I don't think I have gone over this much, but I have removed all the extra transmission coolers from my TJ and I'm just running the TJ Wrangler radiator transmission cooler to cool the down my AW4 which keeps the AW4 around 190° Fahrenheit. I know the AW4 has bad reputation for running hot, but I believe that reputation for running hot comes from the design of the Throttle Valve cable and not providing enough line pressure which will cause the transmission to slip and when the transmission is slipping, it's producing heat.

Couple other things that I learned recently, in fact I learned one yesterday. There are two different flexplates for the AW4 automatic transmission. One is 13.81" outer diameter for the ring gear and the other is 13.83" for the outer ring gear. My flex plate is the large one and it's causing an issue with my starter. I'm ordering the 13.81" flex plate to solve that starter issue. Use ATP Z-337 OR Pioneer FRA530. Now this might just be a requirement for my TDConversions adapter but I thought it was worth noting.

Lastly and I'll be discussing this in an upcoming video, I'm replacing the torque converter (again) on my AW4. The torque converter that comes with the later model XJ Cherokees, ie the AMC 4.0l inline 6, was designed for an idle RPM of between 650 ~ 750 rpm depending if AC was turned on or off. The BEW TDI idles at 910rpm roughly, though you can turn down the idle 882 rpm I believe, I've heard people having the engine stall on deceleration when coming to a stop with the idle set to 882rpm, so I leave mine at 910rpm.

The idle rpm difference of 750 rpm for the stock AMC 4.0l and the 910rpm for the BEW TDI makes it feel like you constantly have your foot on the throttle pedal. The result is that when you go from a Park ➡ Reverse, Neutral ➡ Reverse and Neutral ➡ Drive the engagement is VERY firm and positive. The other side affect to this is you are applying way more brake pedal to keep the vehicle stopped. I was driving my TJ back home yesterday and was stopped at a stop light that was pointing uphil. I was able to barely reduce the pressure on the brake pedal, not lifting my foot off the pedal just reducing the pressure slightly, and my TJ would start to push forward.

I'm having a different torque converter made right now that will hopefully resolve those issues and I will be testing out sometime hopefully in September next month.

I need to address a few things, the gearing is the next big one. These TDI engines like to cruise above 2200rpm, especially over 50mph. Right now I'm at 2160ish rpm at 55mph and I can tell it's not quite happy, but once I get to about 57mph, it cruises great. So I'm looking at going from my factory 3.73 gears to 4.10 gears which will put my 55mph at around 2390rpm instead which will be perfect.

All things being equal I would actually go 3.92 for the axle gear but I can't find a set of 3.92 gears for my front Dana 30 axle, though you can get 3.92 axles gears for Dana 44. I realize that is a small jump from 3.73 to 3.92, but it's kind of crazy how good a set of 3.92 gears would be for my setup and tire size, I would spot on for RPM everywhere. 55mph would 2280rpm which for maximum fuel economy that would be great but I think I'll still end up going 4.10s instead.

That being said, I'm still VERY happy with my swap. Once I get a few of this minor issues resolved, the starter being the biggest headache at the moment, I'm going to start really putting this TJ through it's paces to see what it can do. That was probably more detail than you were looking for but I hope that helps and let me know if you have any other questions!

Thanks
Grant

 

[XCRN]

It all comes down to the power you are trying to make. I know I'm roughly 160hp and 285 ~ 300 ft/lbs of torque on my tune. With that power I wouldn't really worry about the anything big in the transmission. While you have a ton of torque with this BEW TDI, but you aren't going to get into big torque numbers until full boost. What makes this package so nice is the CompuShift controlling line pressure on the AW4 via information coming from the VW ECU over CANBUS. The CompuShift will increase the line pressure based on a slew of variables, RPM, Engine Load, and Mass Air Pressure (Boost Pressure). Having that clamping force from the line pressure really does make a huge difference.

I don't think I have gone over this much, but I have actually removed all the extra transmission coolers from my TJ and I'm just running the TJ Wrangler radiator transmission cooler to cool the down my AW4. I know the AW4 has bad reputation for running hot, but I'm not the point now where I believe that is mostly because of the Throttle Valve cable and not providing enough line pressure which will cause the transmission to slip and when the transmission is slipping, it's producing heat.

Couple other things that I learned recently, in fact I learned one yesterday. There are two different flexplates for the AW4 automatic transmission. One is 13.81" outer diameter for the ring gear and the other is 13.83" for the outer ring gear. My flex plate is the large one and it's causing an issue with my starter. I'm ordering the 13.81" flex plate to solve that starter issue. Use ATP Z-337 OR Pioneer FRA530. Now this might just be a requirement for my TDConversions adapter but I thought it was worth noting.

Lastly and I'll be discussing this in an upcoming video, I'm replacing the torque converter (again) on my AW4. The torque converter that comes with the later model XJ Cherokees, ie the AMC 4.0l inline 6, was designed for an idle RPM of between 650 ~ 750 rpm depending if AC was turned on or off. The BEW TDI idles at 910rpm roughly, though you can turn down the idle 882 rpm I believe, I've heard people having the engine stall on deceleration when coming to a stop with the idle set to 882rpm, so I leave mine at 910rpm.

The idle rpm difference of 750 rpm for the stock AMC 4.0l and the 910rpm for the BEW TDI makes it feel like you constantly have your foot on the throttle pedal. The result is that when you go from a Park ➡ Reverse, Neutral ➡ Reverse and Neutral ➡ Drive the engagement is VERY firm and positive. The other side affect to this is you are applying way more brake pedal to keep the vehicle stopped. I was driving my TJ back home yesterday and was stopped at a stop light that was pointing uphil. I was able to barely reduce the pressure on the brake pedal, not lifting my foot off the pedal just reducing the pressure slightly, and my TJ would start to push forward.

I'm having a different torque converter made right now that will hopefully resolve those issues and I will be testing out sometime hopefully in September next month.

I need to address a few things, the gearing is the next big one. These TDI engines like to cruise above 2200rpm, especially over 50mph. Right now I'm at 2160ish rpm at 55mph and I can tell it's not quite happy, but once I get to about 57mph, it cruises great. So I'm looking at going from my factory 3.73 gears to 4.10 gears which will put my 55mph at around 2390rpm instead which will be perfect.

All things being equal I would actually go 3.92 for the axle gear but I can't find a set of 3.92 gears for my front Dana 30 axle, though you can get 3.92 axles gears for Dana 44. I realize that is a small jump from 3.73 to 3.92, but it's kind of crazy how good a set of 3.92 gears would be for my setup and tire size, I would spot on for RPM everywhere. 55mph would 2280rpm which for maximum fuel economy that would be great but I think I'll still end up going 4.10s instead.

That being said, I'm still VERY happy with my swap. Once I get a few of this minor issues resolved, the starter being the biggest headache at the moment, I'm going to start really putting this TJ through it's paces to see what it can do. That was probably more detail than you were looking for but I hope that helps and let me know if you have any other questions!

Thanks
Grant

Any details always help! I am following this and reading everything. This looks like a solid route to go if using an auto. So are you going with a custom spec torque converter or one from another vehicle?

 

[RustyAutoholicGuy]

Any details always help! I am following this and reading everything. This looks like a solid route to go if using an auto. So are you going with a custom spec torque converter or one from another vehicle?

It's a custom spec torque converter, once I know it works I'll post where I was able to get this torque converter from. While other A340 family transmission are similar, ie the Toyota 4Runners and Tacomas, they have a different mounting pad setup and internal spline count from what I've researched it.

I'm hoping to get the torque converter solved this idle rpm difference between the two engines. I'm working with a few different individuals and companies to get this figured out so my build can be used as a reference for anyone that wanted to do a TDI ➡ AW4 swap in the future, though this would also be applicable to TDI ➡ Toyota A340 automatic transmission as well.

Thanks
Grant

 

[XCRN]

It's a custom spec torque converter, once I know it works I'll post where I was able to get this torque converter from. While other A340 family transmission are similar, ie the Toyota 4Runners and Tacomas, they have a different mounting pad setup and internal spline count from what I've researched it.

I'm hoping to get the torque converter solved this idle rpm difference between the two engines. I'm working with a few different individuals and companies to get this figured out so my build can be used as a reference for anyone that wanted to do a TDI ➡ AW4 swap in the future, though this would also be applicable to TDI ➡ Toyota A340 automatic transmission as well.

Thanks
Grant

So I am not at all familiar with what you can do tuning wise with a TDI since I am coming from LS and HPTuners and Holley, but are you not able to change the target idle speed to match closer to a 4.0?