Trying to get it mostly right the first time: A 5.9 Magnum, 46RE swapped and tummy tucked daily driver TJ

Awesome, glad you've got it running and driving.

9 MPG even with your foot in the floor is lower than I'd expect. Have you checked for codes? The other thing to do is check your PCM numbers for the Death Flash list.
I am in total agreement that they should have offered a V-8 in the TJ.
Will a bumper with a built in hitch work for you? I have a cargo trail that I pulled behind mine also and had a bumper with a hitch but you do have to be careful if you do get one that it has the clearance behind it to get the stinger in or modify one that is for your Jeep only.

I have an FRP tune in the ECU so that's ruled out. Its not throwing a CEL, but I haven't hooked up my scanner to read the O2 sensors, fuel trim, Etc. I suspect there is a small vacuum leak or something else minor.

A bumper with a built in hitch is my end goal but what I want is either too expensive or I have to build it (which I'm leaning toward right now). This Ruff Stuff bumper caught my eye recently though: https://www.ruffstuffspecialties.com/R2605-H.html .
 
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I have an FRP tune in the ECU so that's ruled out. Its not throwing a CEL, but I haven't hooked up my scanner to read the O2 sensors, fuel trim, Etc. I suspect there is a small vacuum leak or something else minor.

Is it a canned tune? Done any data logging for Ryan?

Most guys who'd done the 5.9 were reporting 14-21 MPG once they got over the new power and could keep their foot out of the
floor.

A bumper with a built in hitch is my end goal but what I want is either too expensive or I have to build it (which I'm leaning toward right now). This Ruff Stuff bumper caught my eye recently though: https://www.ruffstuffspecialties.com/R2605-H.html .

This is the one I went with.

https://www.swagoffroad.com/collections/swag-jeep-tj-yj-rear-bumper
 
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That’s insane! I knew I should have done a Magnum!

What do you get with the Hemi? I never drove mine enough on road to tell you what my MPG was. Off-Road I always used close to what the guys with a 4.0 were using. But this was with my 5.2 and IMO it was never running correctly.
 
What do you get with the Hemi? I never drove mine enough on road to tell you what my MPG was. Off-Road I always used close to what the guys with a 4.0 were using. But this was with my 5.2 and IMO it was never running correctly.

Ahhhhh….26??

:rolleyes:
 
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Most guys who'd done the 5.9 were reporting 14-21 MPG once they got over the new power and could keep their foot out of the
floor.
For comparison, my RamCharger with 408 stroker, 37"s and 5.13's was pushing ~11 mpg around town and short highway trips. The current owner says he pushes 13 mpg towing his trailer and UTV.
 
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After enduring FB Marketplace for enough weeks it was time for the Dodge to go to the scrap yard. I loaded it onto my new to me trailer and headed to the scrap yard after work. And yes, it’s really convenient having access to reach lifts at work!

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Right before Christmas my wife’s car ended up in the shop for almost 2 weeks due to a failed ECU, which put the TJ into true daily driver status… ready or not. It didn’t develop any new issues and was a joy to drive, although heat sure would have been nice when it hit low teens in Alabama that week.

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I took the week off between Christmas and New Years and got in a good weather day to work on the Jeep. The to-do list included installing the rear JKS track bar, angled relocation bracket and new lower control arms, all in an effort to correct the rear pinion angle. This project ended up taking most of a day and rendered a few lessons learned.

The first issue came with the shocks hitting the coil buckets due to the pinion being rotated so far up. Nothing a grinder and cutoff wheel can’t fix. (picture taken mid process).

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The second issue came with the control arms. Core4x4 offers these in 0-6” and 6”+ lift increments and without much thought I ordered the 0-6” Tier 3 arms. Seemed logical. Except for the fact that the arms didn’t have enough adjustment to pull the lower mounts forward enough to roll the pinion like I needed. This doesn’t have anything to do with the arms – in fact I am very impressed with the fit, finish and quality of them. This has everything to do with me not measuring correctly before and after. To get the pinion somewhat close to correct, the track bar was trying (unsuccessfully, might I add) to coexist with the gas tank again. All of my issues revolved around the tummy tuck and relative lift height of the drivetrain, which will all be resolved when I swap in the 8.8 and can clock the bracketry as needed.

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But I had the rest of the day to fix this issue and an 8.8 swap isn’t an afternoon ordeal. Since I couldn’t rotate the pinon to meet the transfer case, maybe I could drop the transfer case to meet the pinion. If you recall from earlier, the front output shaft of the transfer case was hitting the crossmember and I’d installed a few washers as a quick fix to gain the needed clearance with the intent to remove them and fix this issue properly later. Well, later was now (and fingers crossed this was enough!). I unbolted the transfer case and lowered it until the angle finder read zero. This is how much I needed... about 3 washers worth.

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I removed the crossmember, notched and plated the cut and reinstalled. I re-checked my angles and everything was good to go. The test run was to a local favorite restaurant:

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It was 70 in December, so if course we took the top off. It still as a slight vibration at 45mph, but overall much better than it was. We also took the TJ through a drive through Christmas light display in town, which was brilliant considering it was pouring rain and the oil pressure at idle is sub-par.

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Total miles so far: 725.
 
To get caught up from the past month: January brought some pleasantly warm weather and an invite to go wheeling at Morris Mountain ORV park in Delta, AL. If you’re not familiar with MMORV…


I used this as an opportunity to get my new trailer dialed in with a relocated jack, toolbox, storage rack, tie downs and a winch mount. I’m a bit of a trailer geek and probably enjoy working on or building trailers as much as I do anything else. Out came the grinder and trusty $100 Harbor Freight Vulcan welder.

First was to move the jack forward to allow room for the toolbox and still have room for the tailgate of my truck to lay down.

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Next was to weld on 8 d rings to fill in the gaps where the stake pockets don’t quite work for tying down a vehicle.

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I use my trailers for a lot more than just hauling vehicles and have found a winch and storage to be absolutely invaluable accessories for keeping all the gear I need to drag home new projects. This trailer is no different and got a receiver welded to the front rail for my multi mount winch and a toolbox and storage rack added to the tongue. The rack is designed to carry a gas can and have room for a spare tire but I still haven’t committed to the final design.

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Loaded up.

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My riding group is all RZRs so I felt like I brought a knife to a tank fight. Luckily, the access roads in this park are great and I was able to follow the group all day.

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Since this was my first time wheeling a TJ and the first time I’ve had it out in the woods I absolutely babied it and probably looked like an idiot – but I really didn’t care since I was having a ball.

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Obligatory poser shot.

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This brings the thread up to today. The TJ has been getting driven around town really without issue. I’ll get back to wrenching on it once the weather warms up and I have the water toys prepped for the summer. All of the wrenching will be covered here when I get back to it.

Speaking of water toys… remember when I said my trailers get used for a little bit of everything? Yep, I launched a Seadoo on a trailer…off the equipment trailer to retrieve my latest purchase.

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Awesome build man! Got any video of it going down the road? I know that exhaust note sounds so good, haha!

Glad to see another Alabama Jeeper on here... I'm an hour and a half south of you near Montgomery. I hope to see that beast in person sometime.
 
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It’s been a minute since I’ve updated this thread, which is largely due to the aforementioned Seadoo project taking on a life of its own and not wrenching on the TJ at all. I ended up buying a total of 5 skis, 2 trailers and a dock and am almost through fixing and selling what I’m not keeping.

The TJ has just over 2k miles on the swap and has had its first real issue that had to be addressed. A few months ago I was out running errands, shifted to reverse to back out of a parking spot and was met with a grinding sound that makes nails on a chalkboard seem pleasant. The best way to describe the sound is like trying to shift a manual trans into gear without using the clutch. Oddly enough, I shifted to drive and the noise went away and the TJ continued to run and drive fine, except for the grinding noise which would occur fairly random. I learned through trial and error that I could shift the transfer case into 4wd when reversing and the grinding went away, so I was confident the transfer case was where my problem lied.

Long story short, the grinding got too frequent for me to ignore so I parked the TJ a few weeks ago until I could diagnose the issue. I pulled the transfer case this weekend and found the fluid to have some super fine metallic color to it, but no large pieces. I had the transfer case sitting on a table with the input shaft facing down and stared disassembling it to find the problem. Disassembly revealed that the gear that engages the planetaries for low range had wear on the face of the gear teeth, like was attempting to engage.

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That didn’t really make sense.

What also didn’t make sense was how the shift collar that engages the front output didn’t seem to have the travel to disengage the front drive, which I also knew didn’t add up. I laid the case on its side, grabbed the input shaft and found 1/2” of play front to back.

That’s DEFINITELY not right.

Look at the gap from the snap ring to the bearing:

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I looked at parts diagrams and confirmed I wasn’t missing a shim, so next was to check the bearing size on the Dodge transfer case (remember, don’t throw ANYTHING away until you’ve been done with this swap for a while!) and sure enough:

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Found it. I’d swapped the input shaft and hadn’t verified that the bearing was the same which was causing the input shaft and planetaries to shift front to back. I reassembled the case using the Dodge front half and reinstalled the transfer case with no issues. A rigorous test drive will be conducted this evening in the form of an ice cream run, likely for Bruster’s Southern Banana Puddin’.

The TJ is on deck to make a drive to the beach in September, so the push is about to be on get it road trip ready. If that trip goes well, the next outing will be a road trip in October to Ashville, NC then to Knoxville, to Nashville then back home. There should be a day of wheeling at Windrock in there somewhere, so this trip will be my goal to get the TJ completed (well, as ‘done’ as a jeep ever gets, right?)
 
awesome detective work LOL.

mine has also been laid up for a while due to the Dana 35 eating itself. Here in the next few weeks it will be on the road with a Dana 44 in it.

what Jet skis did you acquire? I have 2 2008 Seadoo's 155 GTI's. After gauges for both of them and DESS switches and output shaft seals and 1 computer we take them down to the gulf at least twice a month.

did you ever come up with a list of part numbers for your AC components?

the road trip sounds fun, I have yet to travel that far in mine.
 
awesome detective work LOL.

mine has also been laid up for a while due to the Dana 35 eating itself. Here in the next few weeks it will be on the road with a Dana 44 in it.

what Jet skis did you acquire? I have 2 2008 Seadoo's 155 GTI's. After gauges for both of them and DESS switches and output shaft seals and 1 computer we take them down to the gulf at least twice a month.

did you ever come up with a list of part numbers for your AC components?

the road trip sounds fun, I have yet to travel that far in mine.

I saw the damage on your Dana 35 - impressive!

I picked up a 2014 STX 15F, 2005 VX110, 2007 VX110 and 2 2002 GTXs. The STX has been sold and one of the VX110s will be sold once I get it sorted out. The last GTX I purchased was number 35 to roll through my stable since I started messing with them in 2011.

AC is on the short list for the beach trip prep and I believe I've found a combo that will work with OEM parts. I hope to have an update on that in the coming weeks.
 
I’ve gotten a few days to wrench on the TJ in the past weeks and have gotten several things knocked off the list.

First up on the list was to replace the current Magnaflow 12866 with the newer and much larger 12276. I picked this muffler due to the center inlet and outlet and the case size being the largest I could reasonably fit in the space that I had. Check out the size difference in the 2 mufflers. If size is any indication of noise level, this should be a step in the right direction:

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Before I could install the new muffler I wanted to delete the trailer hitch and rear stock rear bumper in favor of a low profile rear bumper with an integrated rear hitch. I looked at several units and ultimately decided on a Barnes 4wd bumper. After scuffing it with a red scotch brite pad, a few coats of self etching primer and gloss black paint later it was ready to install:

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The bumper looked great but now the tail pipe and gas tank skid stuck out like a sore thumb. First to fix was the tail pipe. The muffler install went surprisingly smooth – the old muffler and intermediate pipe were removed, intermediate pipe was trimmed down and new muffler was installed in its place. I’ll post a better picture when I can get the TJ up on a lift, but trust me when I say that everything fits snugly in place. Eventually I’d like to re-work the intermediate pipe to fit a little better but it’ll do for now.

I wanted the tail pipe tucked up as high as I could possibly get it and after some creativity with the stock exhaust hangers, this was the result:

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Bingo.

The exhaust hangers are temporarily permanent. The mount in front of the axle was clocked 90* to provide the lift that I needed. I’ll drill and tap the second hole and this should work just fine.

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The rear mount is currently sitting like this:

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The plan is to swing the factory frame side exhaust hanger forward, use the stock rubber isolator and attach it to a new hanger welded to the tailpipe. Speaking of tailpipe – I plan to either cut the current tip down or weld on a new tip that tucks up closer to the bumper.

Next was to paint the gas tank skid. After a few minutes of prep with the Harbor Freight surface conditioning tool and a few coats of gloss black paint I had the back end of the TJ looking much much better.

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The next items on the list are to add another layer of insulation to the tub and get the A/C operational. I plan to do a detailed post on the A/C setup that I landed on. It's not terribly complicated, but did take a lot of research to finally land on a good solution that didn’t cost a fortune.
 
The next items on the list are to add another layer of insulation to the tub and get the A/C operational. I plan to do a detailed post on the A/C setup that I landed on. It's not terribly complicated, but did take a lot of research to finally land on a good solution that didn’t cost a fortune.

Curious to see what you have come up with on the A/C. Since I'm switching manifolds and can fit a A/C compressor again I might consider putting A/c back on mine once I've got it running and driving.
 
I’ve neglected updating this thread and am working on updates as there have been quite a few. Enter the last weekend in August and t-minus 4 weeks to get the Jeep road trip (and mild wheeling) ready.

I originally installed Noico 80mil sound and heat deadening mats and the product worked well, but with this TJ being a daily driver I wanted to add another layer of heat and sound insulation to the tub to really get it closer to Cadillac status. I went on Amazon and looked for the cheapest and thickest insulation I could find and landed on this AggSound 157mil Sound Deadner. 1 roll did 98% of the area from the dash to the back of the seats and made a huge difference on the floor temperature and some noticeable sound difference. Yes, this will be a nightmare if I ever get water or mud inside the tub, but we’ll cross that bridge when I get there.

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While I had the interior out it was a good time to actually install the console instead of it just sitting kinda in place. After a lot of in and out and finally cutting out the spare change tray / optional airbag switch, I finally had it bolted in for good. I haven’t figured out what to do with this hole yet, but plan to clean it up and make use of that space.

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Working down my punch list, I finally wired in the trans temp gauge and installed a set of Tuff Country extended brake lines that I got on super clearance from JustDifferentials.com. These brake lines are made by Crown Performance and are great quality.

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Nope, still haven’t bought new springs yet.

The TJ was getting due for an oil change and I haven’t been thrilled with the oil pressure with the 10W-30, so I opted to go with Shell Rotella T4 15W-40, a quart of Lucas Oil Stabilizer and of course a Wix filter. I also installed a mechanical oil pressure gauge that is tee’d in with the stock sending unit so I can compare the 2 values. The oil pressure was substantially better after this oil change and the mechanical gauge verified that the stock gauge was within a few PSI.

A fire extinguisher that had been rolling around in the back floor board was finally mounted to the roll bar with a Synergy Mfg. Mount and a few hose clamps. I don’t care if you have a daily driver Prius or a throw down rock bouncer, they all need the correct fire extinguisher and YOU need to know how to use it.

More road trip prep incoming....
 
This post is a place holder for an air conditioning tech deep dive.

The short version: I'm using a stock pad mount style TJ receiver / drier mounted to the battery tray, a 96 Dakota line set and purchased a crimper to change a fitting on the Dakota line set and build a custom hose. The A/C has been working fantastic so far.

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The first ‘test’ of the TJ was to go on skidder duty at the lake dragging cut trees onto the bank to be cut and hauled off. I loaded up my 5x8 utility trailer with saws, chains and a tools, cranked the A/C up and hit the road. The trailer and contents might have weighed 800# total and the Jeep didn’t even notice it was back there...but the temperature gages told a different story as the water and transmission temp gauge read warmer than usual but not alarmingly high. About 40 miles in the water temperature gaged spiked to 260 and I immediately pulled off the road to see what was the issue. It hadn’t blown a hose, wasn’t puking its guts out and didn’t show any visual signs of being as hot as the gauge showed, so I opted to turn the A/C off and keep moving until I could at least get to the next exit a few miles down the road. Less than a mile later (felt like 150 miles with the temperature gauge pegged), the gauge fell from 240 back to 220 almost instantly. Relief. That lead me to believe there was an air pocket in the cooling system that had collected at the sensor.

The rest of the day went without issue. I aired down to 15 PSI, bolted the front driveshaft back in and started pulling trees.

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Found a soft spot:

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Then I found a softer spot and made it worse:

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The trip back home was, thankfully, uneventful.

The last few days before we left were spent packing all the little but really important items. Since we’ve never traveled in the TJ I wanted to see how well everything was going to fit in here, so I installed my Motobilt cargo rack and started packing stuff in starting from most important to least. Much to my surprise, there’s a fair amount of room in the back of a TJ with the cargo rack... not saying it will be our new road trip rig, but for 2 people on a 10 day road trip it fit everything we needed.

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To this point I haven't had a front driveshaft since I don’t have adjustable front control arms to correct the pinion angle. I finally decided to bite the bullet and order Savvy and Core 4x4 front arms to match the rear along with a Barnes 4wd cam bolt eliminator kit. I messed up and ordered the wrong length Core 4x4 arms and was not able to use them on the trip. It is worth noting that the 9/16 bolt included with the kit is too small for the Johnny Joint included in the Core 4x4 arms and the plates had to be drilled out to accept the larger bolt.

With the Jeep packed and prepped (as it was going to get) it was time to hit the road to Maggie Valley, North Carolina. Keep in mind that the TJ has never left the state and hasn’t done more than 100ish miles in a day up to this point. So let's go slam 1,000 road miles and a few wheeling miles on it in a week.

Seems fine.
 
WOW you've been using the heck out of that Jeep. Glad to hear you're getting stuff dialed in and that it's working good. Always like to hear another success story on one of these Magnum swaps.
 
WOW you've been using the heck out of that Jeep. Glad to hear you're getting stuff dialed in and that it's working good. Always like to hear another success story on one of these Magnum swaps.

I sure don't plan for this to be a show rig. I'm hoping to get the 8.8 swapped in over Christmas and start wheeling it.