Willys Crawler 2.0 aka The Bastard

Greg

Make RME Rockcrawling Again!
Admin
I picked up a 4L80E from a 2006 GMC Savannah 2500 2WD with 140k miles on it, paid $750 with the convertor. I pressure washed it, the bolted it up to the mockup engine and went straight to checking fitment.

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I was concerned about the transmission tunnel, the PO built it for a TH350/4L60E and it looked tight. My concerns were justified.... the 4L80E hits the firewall & trans tunnel pretty well. I'm going to need to open them up and make room for the big 4L80E. :confused:



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Greg

Make RME Rockcrawling Again!
Admin
Quick update, finished building the roll cage.... most of you saw the progress. I've tried to build it so it will be plenty strong, have decent head clearance and fit the small Jeep tub well. The A pillar "windshield frame" is leaned back much more than stock for a more aggressive look. - https://www.rme4x4.com/threads/cage-building-feedback.118615/

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Also made progress on setting up the 4L80E from 2WD to 4WD with the adapter. I removed the tailhousing first. I'm going to try to use a factory GM aluminum adapter, they can be sourced for $65. GM Genuine Parts 15724745

The t-case will be clockable, so hopefully the factory GM adapter will work without any modifications. The output shaft has 5" of spline and the adapter is 2.5" thick and I'll have 3.5" of spline sticking out, which will need to be shortened. I'll do that with a cut-off disc and air grinder.

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Greg

Make RME Rockcrawling Again!
Admin
I've moved on to test fitting the 4L80E some more, marking out where I need to cut the tub and firewall to make the massive transmission fit the tiny Flatty tub. I'm trying to set the transmission 3" forward from the firewall, but it's all going to be a compromise with moving the engine forward versus tub clearance.

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Also was able to check out the transmission pan position, it sits about 1" below the frame currently. I'd love to have a flat belly and skid plate, if possible! It really all depends on where the t-case ends up, too. I think I'll have to triangulate my rear lowers and run them to a beefy crossmember that will end up sitting under the t-case, so things are going to get real tight, real quick. I'm packing 20#'s of s**t in a 5# bag.

After setting it all up, it looks like I'll have a 20" rear driveshaft. 😲 That's just enough, right?
 

Greg

Make RME Rockcrawling Again!
Admin
Another vote for flat belly, it helps a lot! Awesome build, I have a soft spot for the Willys

Good to see Battle Born on RME! I saved pics of your old Willys as inspiration for this build. 😎 I'll end up with more sheetmetal, but I did love the minimalist look of yours!

Love my Gatekeepers BTW... it took me awhile to get my set, but they were the wheel I wanted.
 

Greg

Make RME Rockcrawling Again!
Admin
What does @cruiseroutfit like to say, "Buy once, Cry once"? Well, that's what I did. Many thanks to Kurt and the crew at Cruiser Outfitters for the excellent customer service, as well as the guys at Advance Adapters for calling to verify the build specs for my Atlas!

It's a 2 speed Trail Series driver drop 4.3 ratio with 32 spine input (4L80E) and 1350 outputs. I did opt for cable shifters, to make mounting the shifters easier.

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Now to figure out how much output shaft to cut off the 2WD 4L80E.... (GM adapter sitting in place)
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Greg

Make RME Rockcrawling Again!
Admin
You know what sucks? When you out-build your own build... :oops:

What do I mean by that? Well, I should have stuck with the original plan to run a 4.3, 4L60E and Dana 300. The PO of this body had it setup with a 4.3, TH350 and D300. When I started up upgrading to a bigger engine, trans, t-case & tire size I knew things were going to get tight. I figured I could make it work. Before I ordered the Atlas, I found some dimensions online and checked what I was working with, laying under the Flatty with a tape measure and trying to see how the big case would fit. It looked like I could make the Atlas work, with it clocked just right. Turns out, I was wrong.... the Atlas is too big, by 1 1/2". :eek:

After consulting with friends, the idea was tossed around to move the drivetrain over so it was offset, but that means chopping into the trans tunnel & will put the exhaust right on top of the frame on the pass side. Another suggestion was to notch the frame, but my suspension links need to tie into that exact location and the body mount would be thrown off.

I'm about 90% sure this may be where this project ends for me. I want to use the LQ4, 4L80E, Atlas, Dana 60 & 70, 39" Krawlers, etc.... but it may have to be a different rig, at this point. Honestly, I'm getting tired of starting over with projects.

Anyone want a Flatty crawler?
 

Tebbsjeep

Well-Known Member
Location
Ogden
Couldn't you "stack" the center frame section with another rail to gain more room for everything? You'll lift it higher, but it might gain just enough clearance to make it work. Then you wouldn't have to start over. Having said that, I've never built anything like this, so it's a total noob suggestion.
 

Pile of parts

Well-Known Member
Location
South Jordan
Crap!!!
So am I understanding correctly that the frame is too narrow? If so, is there any reason you can't angle the frame rails out from the firewall section? You could even angle back in at the rear of the tub for suspension components/tire clearance, etc. You could fab up something similar to the Motobuilt kit for the angle out and back in. Sure, you'd have to build body mounts. It's frustrating to have to go backwards but you have a good direction and we'd all love to see you on the trail in it.

 

Hickey

Burn-barrel enthusiast
Supporting Member
It's hard for a lot of people to see, but Greg is 100% spot-on when he said it's a victim of scope creep. The more he changes it from the original plan, the less happy he'll be with the end product. Also, Greg is a motor guy. No way in hell is he gonna not use that beast of a motor, and it's just not a great fit for this chassis/body. He would have to make compromises that kinda suck.
 
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