Brett's '97 TJ VW 1.9L TDi Swap

[TJ Starting]

I'm making a couple assumptions, that he's gonna run 33s, 4.10 ratio. I think he said he's got the ax-15 so that will be around 2300 Rpms at 70. That should be good for the TDI since they tend to get their torque closer to 2k rpm.

Thanks, still new with this kind of stuff. That's one other thing I'm concerned about if I would do a swap. I have the NV3550 which I would prefer to keep for the lower first and second gear, already geared to 4.56 with 33s. Running just a bit under 3,000rpm at 75-80 which wouldn't change at all right?

 

[brett313]

Thanks, still new with this kind of stuff. That's one other thing I'm concerned about if I would do a swap. I have the NV3550 which I would prefer to keep for the lower first and second gear, already geared to 4.56 with 33s. Running just a bit under 3,000rpm at 75-80 which wouldn't change at all right?

Correct. At that point you have two ways to lower your final drive ratio, you could regear your axles, or run a larger set of tires.

For you: at 65, 70, 75 respectively assuming i got the trans right.

2354

2535

2716

http://www.grimmjeeper.com/gears.html

 

[TJ Starting]

Correct. At that point you have two ways to lower your final drive ratio, you could regear your axles, or run a larger set of tires.

For you: at 65, 70, 75 respectively assuming i got the trans right.

2354

2535

2716

http://www.grimmjeeper.com/gears.html

Yep sounds correct. I'm guessing that's less then optimal for a tdi diesel. I'd really prefer to keep that final gear ratio for 4low, I guess I could regear axles to a higher ratio then get a four speed atlas or a 241 which is a really expensive way to arrive at the final destination, ain't happening. Might have to rethink this one.

 

[BugoutJeep]

could you get by with a 5:1 atlas 2?

It stinks but maybe look at the 6l80e auto transmission and do a GPS speedometer and atlas 2. it's got a .6 od I think.

 

[brett313]

Yep sounds correct. I'm guessing that's less then optimal for a tdi diesel. I'd really prefer to keep that final gear ratio for 4low, I guess I could regear axles to a higher ratio then get a four speed atlas or a 241 which is a really expensive way to arrive at the final destination, ain't happening. Might have to rethink this one.

I'd be suprised if people weren't up for trading axles, most people are wanting to go deeper to your 4.56 from 3.73 or 4.10. Could save you a bit of money depending (hopefully you don't already have lockers?) then go with a 241 or other.

 

[TJ Starting]

could you get by with a 5:1 atlas 2?

It stinks but maybe look at the 6l80e auto transmission and do a GPS speedometer and atlas 2. it's got a .6 od I think.

You've kinda lost me on exactly what atlas you're talking about but I really I don't see it a possibly on just redoing my whole driveline right now. I'm still pretty young and have plenty of financial things to take care of right now. And also not to be one of "those guys" but really dont want to be putting a auto in my jeep.

 

[TJ Starting]

I'd be suprised if people weren't up for trading axles, most people are wanting to go deeper to your 4.56 from 3.73 or 4.10. Could save you a bit of money depending (hopefully you don't already have lockers?) then go with a 241 or other.

I could see that as a possibility, I'll have to think about that. I do have lockers but they're just auto lockers installed by the po.

 

[BugoutJeep]

You've kinda lost me on exactly what atlas you're talking about but I really I don't see it a possibly on just redoing my whole driveline right now. I'm still pretty young and have plenty of financial things to take care of right now. And also not to be one of "those guys" but really dont want to be putting a auto in my jeep.

I wouldn't even regear. I think it'll be fine. You may lose a little mpg, but not much especially if you don't have to buy an Atlas or regear.

I bet you'd a good price for those axles though, but maybe run 35s and just go 65 if mpg is a concern.

 

[BugoutJeep]

I could see that as a possibility, I'll have to think about that. I do have lockers but they're just auto lockers installed by the po.

I would sometime down the road put in a selectable rear locker. I've had rear auto lockers be annoying.

 

[TJ Starting]

I wouldn't even regear. I think it'll be fine. You may lose a little mpg, but not much especially if you don't have to buy an Atlas or regear.

I bet you'd a good price for those axles though, but maybe run 35s and just go 65 if mpg is a concern.

Yes, maybe this could work out. Could definitely be done in stages too. Also yes, plan is eventually have a Eaton in the rear.

 

[BugoutJeep]

Yes, maybe this could work out. Could definitely be done in stages too. Also yes, plan is eventually have a Eaton in the rear.

It's my understanding the VW TDI likes Rpms a bit more than other diesels we're used to. I think you'll be happy with the gearing. The TDI isn't a 6BT but those gears will make the 1.9 feel like a bigger engine.

Those gears will be almost required for a decent crawl ratio too. I have to have a 5:1 tcase so I can get a decent crawl ratio. That's the only negative IMO for diesels is that they don't need the big gear ratios, which makes them way too fast off road for my preference.

I'm in a bit of a crossroads for my build. I kind of want to use a standard hd tune for my r2.8 to go to 360 ft lbs, but the ax15 can't handle it if I ever stomped the accelerator down. So if I go that route I'd probably swap transmissions. On paper the auto kinda fills in the most pros on paper, but the nv4500 and tr4050 have a lot going for them. Also any change ends up being so expensive now, though technically I could get away with my np231 with the 2 manuals. The auto I'd have to go with the atlas 2 speed, well if I go with the 6l80E, but IMO that transmission would mate perfectly with my diesel with a good 1st gear and practically 2 ODs which could get me a bit more mpg and range on the highway. But that route, I'd probably have $6k in and that's not negligible.

 

[BugoutJeep]

View attachment 240037
Clearances the 4.0 bell housing for the new starter motor location. Not the prettiest, but it works, or at least it will self clearance . I may tig a small cover plate to prevent stuff from getting in , but there are so many other holes on the bell housing already im not sure it matters....

Does anyone know if the factory bell housing has plugs or covers to keep dust out or if that’s a common mod? Do you need the clutch area to “breathe” ? I know this is a noob question I’ve just never thought about it so bear with me

My R2.8 has a big hole at the base and it's threaded for standard pipe, but I never plugged mine and that seemed to be something most don't bother with for whatever reason. If you're worried maybe find one of those plastic plugs or something like a freeze plug and pop in there.

 

[BugoutJeep]

Thinking of running the 4.56s has got me thinking about a TDI build again. In some respects it would be cool to be able to build a Jeep truck that's capable of towing like a half ton with a small 4 cylinder engine. I could imagine building one of the TDIs to somewhere around 190hp, which I would assume is a bit over 300 ft-lbs. With 4.56 with a 6L80E I would have a really nice OD and pretty good gearing to get my rig moving.

On the other hand and looking at HP kit pricing, building a TDI for that kind of HP, I'd probably be better with 4.10s or 4.56s, 33s (maybe 31s for towing), R2.8 with a 360 ft-lb tune (though I'd prefer an engine 400-500 lb-ft). Those TDI kits are like $5k and I'm not sure if there isn't more stuff I'd need. Of course if I want AC for the YJ truck then the R2.8 will negate the TDI hp kit, because it's $3k for AC with the R2.8 because the bracket is $1,500 (part of me wants to try and find a drawing and see what a casting would cost and then finish mill at home to save some cash).

The cooling packages for the R2.8 will also cost a lot more too. The R2.8 and many modern diesels need A LOT of cooling which confuses me from my experience with tractors and some earlier diesels so I'm not sure what's the necessity of needing so much more cooling. In a gas tractor the radiator for the diesel or the gas will be the same for the HP diesel or gas and even then the diesel will run cool when not working, but tends to like running hotter under load where you get max efficiency. I kind of wonder if it's the tuning of modern diesels to make them less efficient that is part of the conundrum. Maybe it's the additional mass of the older diesel engines? Maybe it's emissions tuning? I know there are a fair amount of air cooled diesel tractors still kicking around here and they're crazy efficient from what I've been told.

 

[brett313]

...

On the other hand and looking at HP kit pricing, building a TDI for that kind of HP, I'd probably be better with 4.10s or 4.56s, 33s (maybe 31s for towing), R2.8 with a 360 ft-lb tune (though I'd prefer an engine 400-500 lb-ft). Those TDI kits are like $5k and I'm not sure if there isn't more stuff I'd need. Of course if I want AC for the YJ truck then the R2.8 will negate the TDI hp kit, because it's $3k for AC with the R2.8 because the bracket is $1,500 (part of me wants to try and find a drawing and see what a casting would cost and then finish mill at home to save some cash).
...

This isn't directed at you at all just giving general info, but IMO the second you start paying out for a ton of TDI 'swap kits' you lose the economical value of doing a TDI swap.

All said and done, If i was just adding up the total amount of every part required for building a TDI jeep (skipping things like the tummy tuck/Body lift, AX-15, and new axle/lift stuff)

total	$3750 ish
Donor TDI	$1100 (don't pay more than this buy blown Auto trans model)
Engine/Trans Adapter	$1300
Rear Driveshaft	$500
Tune/Swap Related deletes	$320
Metal and Fab	$150
Various (fuel lines, new timing belt kit, new clutch)	$500

Obviously this won't net you a newly rebuilt motor, but I don't want people thinking it costs 10k to do a TDI swap. Many ALH will make it to 300k miles and further with proper maintenance and maybe a new turbo thrown in there ($1k). You start buying mounting solutions/ accessory brackets/ boost routing instead of DIY then it gets up there at nearly $2k per 'kit'. If i was dropping that much the r2.8 looks much better on paper.

 

[BugoutJeep]

This isn't directed at you at all just giving general info, but IMO the second you start paying out for a ton of TDI 'swap kits' you lose the economical value of doing a TDI swap.

All said and done, If i was just adding up the total amount of every part required for building a TDI jeep (skipping things like the tummy tuck/Body lift, AX-15, and new axle/lift stuff)

Obviously this won't net you a newly rebuilt motor, but I don't want people thinking it costs 10k to do a TDI swap. Many ALH will make it to 300k miles and further with proper maintenance and maybe a new turbo thrown in there ($1k). You start buying mounting solutions/ accessory brackets/ boost routing instead of DIY then it gets up there at nearly $2k per 'kit'. If i was dropping that much the r2.8 looks much better on paper.

I wanted my swap to go quick, so I was kit bound and though the R2.8 and kit is expensive, it was almost as expensive as the TDI for a rebuilt engine. I will note that the R2.8 kit was cheaper when I bought it and the COTY stuff hasn't moved much. I think without any extras (you're gonna have extras) it was around $16k R2.8 with kit vs $14k or something TDI and probably about that for a 4BT, which I was trying to avoid.

In all honestly and maybe if I had to do it over again, I'd make a truck build first and then on the side do a super lightweight and nimble TJ with the TDI. But life always seems to unwind in a way you don't foresee. I didn't foresee towing as often as I do and I want to have a very good backup option to my 3/4 Ton (I treat it as a 1/2 ton). I know plenty of guys that have newer half tons and when they start towing regularly they have major transmission or engine issues. I have an older F-150 from the late 90s and it's probably the worst truck I've ever encountered, besides probably a V6 truck. Power is fine, it just needs a lot of fuel and lots of engines. When I tow our camper, every fuel trip is an adventure. In the diesel truck, I take a couple 5 gallon cans and with well over 500 mile range between the fuel cans and the tank, I really don't have to think about stopping anywhere, not that I've been able to travel much with the camper.

I may scrap my YJ truck idea though, but I'll probably be getting some truck and at this point it's gonna be somewhere around $35-$45k for a used truck or diesel Gladiator (this will need some mods to meet my usage criteria). Those kind of funds would make 1 hell of a nice YJ truck.

But the price of new and used trucks, IMO makes these builds more viable options. Though besides just fitting I do plan for a full restoration of pretty much everything with known reliable components or at least as much as possible and go for simplicity where I can, but the wife is gonna want an auto or maybe even a manually shifted auto (even if she doesn't admit it, I don't like the smell of burning clutch) and she'll probably prefer AC.

Btw, I do suggest that when the engine is out, I think you'd be miles ahead to pull the tub up enough to do ALL of your rust prevention/fixing stuff and new brake lines at the same time. Even if I wasn't experiencing rust for an older vehicle I think rust prevention is a good idea.

 

[RustyAutoholicGuy]

@Bugout is there a transmission controller for the 6L80 transmission? I went with a Ford 6R80, joint venture between GM and Ford, because I could find a standalone controller for it, I haven't been able to find one for the 6L80 though.

Thanks
Grant

 

[BugoutJeep]

@Bugout is there a transmission controller for the 6L80 transmission? I went with a Ford 6R80, joint venture between GM and Ford, because I could find a standalone controller for it, I haven't been able to find one for the 6L80 though.

Thanks
Grant

I'm honestly just guessing/ballparking for the 6L80E. I've seen some guys on here with LS motors that have mentioned them and I see adapter plates that mention the GM stuff like the 4LXX stuff. I have done very little with automatic transmissions, but looking at gear ratios for the 6L80E I was excited, maybe the Ford 6R80 is similar which would be nice to have some options.

There's a part of me that would like to switch to a different transmission for my build so I can turn up the torque a bit. Also that .6X OD would probably even help my range slightly on the highway and the 1st gear for the AX-15 is just too fast for my liking. However it's expensive to change all of that stuff and the AX-15 is a nice size and it's ok.

 

[RustyAutoholicGuy]

I'm honestly just guessing/ballparking for the 6L80E. I've seen some guys on here with LS motors that have mentioned them and I see adapter plates that mention the GM stuff like the 4LXX stuff. I have done very little with automatic transmissions, but looking at gear ratios for the 6L80E I was excited, maybe the Ford 6R80 is similar which would be nice to have some options.

There's a part of me that would like to switch to a different transmission for my build so I can turn up the torque a bit. Also that .6X OD would probably even help my range slightly on the highway and the 1st gear for the AX-15 is just too fast for my liking. However it's expensive to change all of that stuff and the AX-15 is a nice size and it's ok.

Gotcha so I can add some clarification to some of these.

The Ford 6R80 and GM 6L80 are nearly identical in terms of gear ratios

Gear	Ford 6R80	GM 6L80
1st	4.17	4.03
2nd	2.34	2.36
3rd	1.52	1.53
4th	1.14	1.15
5th	0.86	0.85
6th	0.67	0.69

Both transmission are great for a diesel swap, granny low first gears with two overdrives, one for highway speeds and another for interstate speeds, having 6 speeds will allow whatever diesel engine you put in front of it to stay in it's ideal torque band.

As for the adapter the 6LXX engines need an LS engine adapter, where as the 4LXX transmission and earlier, ie TH350 TH400 700r4 4L80e etc, are considered pre-LS engines, though I don't know what is different between to the two. That being said I know TDConversions has a LS adapter coming soon for $1199 US but I don't know when it's going to be released. I'm getting a custom TDI to Ford 6R80 made for my swap, I already have the transmission, controller, shifter and it's already mounted in my setup so it makes it much easier.

As for controllers I was able to find a controller for the 6L80 here:
TCM-2650 GM 6L50E 6L80E 6L90E Transmission Controller W/Harness GM 4L80E 4L85E (93+)TCM-2800 HarnessTCM

And here is the controller for the Ford 6R80 transmission:
USShift Quick 6

Another positive with the 6R80, and I'm sure the 6L80 has this as well, is I have engine braking in the lower gears as well, so I get the benefit of engine braking with a manual transmission with an automatic transmission which is awesome.

You will need either a custom adapter to the factory NP231 with a new input shaft, that is what I did for my NP231, it's a 31-spline input and I use a custom adapter as well. Alternatively you could go with an Atlas as well but that is expensive but an option.

Two other things to consider is both of these transmission are HEAVY, something like 220lbs, but there are compact in terms of length but somewhat large in terms of diameter, you'll need to verify your clearance to the tub.

Lastly you will need to run a bigger cooling line for both transmission, running to our factory TJ Wrangler radiators is not an option, the diameter of the inlet and outlet to the radiator is just too small. Again not a big deal but something to keep in mind!

Hope this helps!
Thanks
Grant

 

[brett313]

@Bugout is there a transmission controller for the 6L80 transmission? I went with a Ford 6R80, joint venture between GM and Ford, because I could find a standalone controller for it, I haven't been able to find one for the 6L80 though.

Thanks
Grant

This product page has some decent info,

http://www.zerogravityperformance.c...ic-transmission-controller-6l80e-6l90e-6l50e/
looks like it’s possible to get behind whatever engine, but it’s going to be expensive

Edit just caught your latest post one step ahead of me

 

[BugoutJeep]

Look what I found....

https://quickdrawbrand.com/product/...r80-automatic-ford-with-quick-six-controller/