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Gen V swap questions

10K views 29 replies 8 participants last post by  0lllllll0 RPMEXTREME 
#1 ·
I found a 2018 LT L83 engine with a 8l90 Trans and Tcase 30k miles locally and at $1500. Comes with harness and accessories. I figure sold, but I can't seem to find too much on install. I emailed Robbie at Motech a few days ago but still no response.

I suck at wiring and would prefer some no measure type of engine and trans mounts to help me along, but I'll piece the rest of the needed parts as I go.

Looks like I can keep the NV241OR and sell the 3.8 new trans and chevy tcase, with the tcase pretty much paying for engine and trans from what Im seeing them go for online, but may have to ditch the rubicon case since Im running 5.13s and the trans having such a low 1st gear as well, but ill figure that out later.

Has anyone done a Gen V swap yet, themselves? All the posts Ive seen leave my questions unanswered or they had someone do the swap. Im too poor for that.

Or if you're BFFs with The guys at Motech, RPM and whoever else, I'm seeking a plug and play harness and engine/Trans mounts. Or if you wanna spoon feed me links that I may have over looked, I am ok with that too.
 
#5 ·
I did find a way to use the Rubicon case on the 8l90 but it was accidental. Specifically looking for it gets me nowhere, unless it's the same as the 6l80 then RPM has it. Either way, as mentioned above, using the 241OR isn't going to do me any favors. Plus make some money back selling it. See if I can run the stock tcase that's on the LT set up.

Guy, I did see that post but at 2am, I saw the opening message talking about the Gen IV I skipped over it. Thanks for posting it back up, it definitely answers my questions. Appreciate ya.

I hate cold calling because in my head I imagine them being busy as hell, just like I am and during the daylight hours, hard to be sitting on hold. figure with an email, they can get back to me when they can without being rushed.
Not sure why I think that, but it's my first instinct.
 
#7 ·
Either way, as mentioned above, using the 241OR isn't going to do me any favors. Plus make some money back selling it. See if I can run the stock tcase that's on the LT set up.

I've never understood the "can't use the 4:1 TC because it's too low for the low first gear". Well then.........run it in second or third.:dunno:

Where are you located? I have the non-rubi TC out of my Jeep still sitting here, has 26k on it. I'd like to get rid of it, but I'm not dicking with shipping it
 
#11 ·
HMS, why so low? Just trying to get rid of it? Looking online, they go for a pretty penny.

Guy, I'm actually only 2 hours from you when I am not working in that area. What are you trying to get for it? I also figured a different trans gear but people smarter than me have said it's a no go.

As for the 241OR, I know they are strong as hell, just not as strong as a 205. Chain and case being the weak link. I do recall reading the torque numbers being way up there and able to run 400+HP though. I suck at math so cant really tell you what the torque rating would read out as in 1st/Lo but I feel like Id be going nowhere with 4:1/4.56 1st/5.13s.
 
#15 ·
I'd take $100 just to free up the space. PM me when you know you'll be near if you decide you want it , I work out of country, so I'm gone for months at a time. In fact I'm headed to Egypt in a couple weeks for probably a month. I'm not actively trying to sell it, so it's not going anywhere.
 
#12 ·
I did the swap myself using a Motech kit. L86/8L90/Atlas. Using a L83 will reduce some costs in the cooling department, but I think that's really minimal.

Your rubicon transfer case is not compatible, and I don't think you can control the GM transfer case without a BCM, but I'm not sure on that. It's a long transfer case. I would suggest to get a normal JK Case if doing this on a budget.

Read the Motech documents a few times, lots of good info there. Downloads

The kit is pricey, but overall it is well thought out. You will need to send them your jeep's engine harness to be reworked as well as the L86's harness. Engine mounts are bolt in and have some adjustment to position the engine where it doesn't hit anything. You will most likely need to lift the body up some. I welded together some washers and got longer bolts, doesn't need but about 5/8".

You will need HP tuners to get it working right and not have the dash lit up. Being a 2018 engine, it's more costly to unlock than the 2016 and down. Go to the HP tuners website for more info on that. The transmission computer is also going to be locked, but you shouldn't need to get into that.

Transmission takes a special oil, it's pricey and may not be available everywhere.

There are a couple guys on this forum that have done the swap, read up. One said he is using the stock JK radiator with his L83. The cooling fan is a different animal but I'm sure there are a few ways of attacking that now. Most expensive way is using a Camaro SS fan controlled by the GM computer. That'll also cool the best.

Even tightest budget, making sacrifices along the way, I bet you're still over 10k before you're done.

But it is worth it!
 
#13 ·
Thanks for the input. I've been reading like crazy. I think I am just going to post up my Engine/Trans/case and just foot the rest of the bill on a cc to make the swap easier than trying to piece it together on something ive never tackled or even seen in person before.

I am running the L83, about to toss it up on the engine stand when I pick up the bolts tomorrow and start removing the harness and to clean up the engine a bit. Fairly dusty. I want to find some numbers to see exactly what I have, I seen the guy has a couple of ads with different years, so I just want to know exactly what I have.

The case is removed from the set and will be sold to fund the swap. Not sure if its the 261 or the other one yet as there is no tag on it, so once I figure that out Ill toss it up.

Motech did get back to me in email with a price but told me I should call for details so once I get free time from work, I am going to do that.
 
#14 ·
I've been watching a few videos and the info Doc they provide in the link and from what I am reading, it's almost like not much is needed outside of electrical stuff and the EZ mounts and the obvious PS mount. My cooling system will work as is. Fuel works as is. Can get the exhaust built locally or through them.

Luckily I wont even need to remove the body.
 
#16 ·
#17 ·
That's pretty cool, never even knew those were available. How thick would the adapter have to be to use this? When I look at the Atlas stuff, I keep wanting to come back to the 241or..

After googling forever, I found out that the engine is actually a 2016. The trans has a 6U8L sticker, so after stressing out google, it finally told me what it meant. Still not sure if the Tcase is a heavy duty unit or not, but NQH-AHA seems to lean that way. Ill let whoever buys it stress over any other info.
Seems the engine came out of a Tahoe or escalade, both seem to have these same options.

Finish cleaning it up and then wait for someone to buy my powertrain.
 

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#18 ·
That's pretty cool, never even knew those were available. How thick would the adapter have to be to use this? When I look at the Atlas stuff, I keep wanting to come back to the 241or...
Our 8L90E adapter bolts up to the stock GM 4wd housing on the back of the trans and is about 3/4" thick. You may have to trim some off of the output shaft to account for the adapter shaft.
 
#23 ·
Anyone know if the gen 5 transmission mount plate is a single flat piece from Motech? I know the Gen 4 are two pieces and Im pretty sure the beta kits were also two pieces, but Im curious if Im missing the bottom piece. Left and email and tried calling twice today. Was curious if anyone knew while I waited. The pic they have on the website is kind of hard to tell.
 
#27 ·
Programming

What did everyone do about flashing? My parts are starting to come in and it seems I can go HPT or FlashCal. I would honestly prefer to have it flashed from someone who knows what they are doing and I can toy with a programmer for tire sizes and such, but I am curious what everyone has actually done.

Reading the process seems a bit daunting, for someone who has never done this before. (It's probably easy like most stuff that reads complication). It's also a bit expensive for something I likely wont use all that often.
 
#30 ·
What did everyone do about flashing? My parts are starting to come in and it seems I can go HPT or FlashCal. I would honestly prefer to have it flashed from someone who knows what they are doing and I can toy with a programmer for tire sizes and such, but I am curious what everyone has actually done.

Reading the process seems a bit daunting, for someone who has never done this before. (It's probably easy like most stuff that reads complication). It's also a bit expensive for something I likely wont use all that often.
Go with HP Tuners. There is a small learning curve to get it installed and operating but it will be well worth it in the end.
The scanner-datalogger is top notch and you will be able to do anything tune wise.

I would recommend first reading the stock files and saving them. then get with someone who tunes and have them make you a good "base" tune to start with.

From there always save the tunes in order and only change one thing at a time until you know what you are doing.
Tune-1.0
Tune-1.2
Tune-1.3 etc....
If you mess something up you can always install the last good tune.

The GEN5 LT tuning is a lot more complicated compared to the GEN4 stuff. Don't go overboard. Work with a good person that knows how to tune them and from there you will mainly be changing small stuff like shift points.
 
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