Jeep Wrangler PCM and module repair and replacement

Upgrading to Dana 60s and 40s

sonnyram

sonnyram

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Dec 18, 2020
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California
Hi guys. I have a 2000 TJ Sports 4.0, 3-speed auto, transfer case 231. I’ve been thinking of stretching it, putting Dana 60s and 40” tires on it. Other than than control arms, steering components, are there any upgrades I need to do on the transmission or transfer case to safely run it on 40s? It’ll be a dedicated crawler. TIA.
 
SYE/Driveshafts, stretch tank or fuel cell, highlines, sawzall work, longarm center section/skid, triangulated four link rear, three link the front, either no or reworked exhaust, rear outboard shock mounts, bigger brake MC.

If you aren't street driving, I'd go full hydro.

You'll want 5.38s in the diffs which will help save the powertrain stress.
 
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What WB are you thinking of stretching to? Are you thinking of doing the TJ6 stretch? You say you're going to keep the 4.0 but will it have enough power?
I've got 38" tires on my TJ right now but am gathering the parts to swap to 40's.. I have a Ford HP44 front & TeraLow CRD60 rear axle. I'm currently sitting at 100" WB and even if I go to 40's I will see what I think of them with the 100" WB.....

Seems the rule of thumb is a WB of 106" to 115" for 40's.
 
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GATORB8 said:
SYE/Driveshafts, stretch tank or fuel cell, highlines, sawzall work, longarm center section/skid, triangulated four link rear, three link the front, either no or reworked exhaust, rear outboard shock mounts, bigger brake MC.

If you aren't street driving, I'd go full hydro.

You'll want 5.38s in the diffs which will help save the powertrain stress.
Click to expand...

Yeah. All of that and then some. I think you can get 5.86 gears in a Dana 60 which, with 40s, would be equivalent to 5.13 with 35s, and that works well with stock or stockish engines.
 
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Woodrow said:
Yeah. All of that and then some. I think you can get 5.86 gears in a Dana 60 which, with 40s, would be equivalent to 5.13 with 35s, and that works well with stock or stockish engines.
Click to expand...

If you are going with low pinion axles... You can get all the way down to 7.17:1 in a Dana 60 that is... Not sure about Dana 70 or 80 and I think 14 bolts only go down to 5.38...
 
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Woodrow said:
Yeah. All of that and then some. I think you can get 5.86 gears in a Dana 60 which, with 40s, would be equivalent to 5.13 with 35s, and that works well with stock or stockish engines.
Click to expand...

I have a similar first gear in the LJ and the 5.38s are decent with the 4.0L/2.72 tcase.

Pretty decent drop in pinion size to hit 5.86s:

1782245968156.webp
1782245983435.webp
 
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Woodrow said:
What do you guys generally think of 40" tires with a Dana 60?
Click to expand...

It's what GenRight builds their rigs with but then you have guys like Jeff & I who seem to break Dana 60 axles....

A front Dana 60 OK most of the time while there are upgraded Dana 60 front axles now with 40 spline axle shafts and there is the 14 front axle now...

It's the rear that can be the issue... Jeff has broken 2-3 R&P's in his HP60 rear and I've broken 3 myself. But theses were both high pinion & semi-floating axles.
So going to a low pinion Dana 60 might not of broken..
 
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Wildman said:
What WB are you thinking of stretching to? Are you thinking of doing the TJ6 stretch? You say you're going to keep the 4.0 but will it have enough power?
I've got 38" tires on my TJ right now but am gathering the parts to swap to 40's.. I have a Ford HP44 front & TeraLow CRD60 rear axle. I'm currently sitting at 100" WB and even if I go to 40's I will see what I think of them with the 100" WB.....

Seems the rule of thumb is a WB of 106" to 115" for 40's.
Click to expand...

TJ stretch. I’ve seen someone used a kit to move rear shock mount to get to 106 WB.
 
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Lanzg said:
We see alot of broken 60s LP/HP, anything heavy, powerful, or 40s and up I'd base my rear end build around something more robust.

14B is such an easy and cheap alternative at least around here, I can't get excited about a 60 in the rear.

LG
Click to expand...

That is my impression with out direct knowledge. But as @Wildman said, he and @NashvilleTJ can't seem to keep a Dana 60 alive with big power and big tires. Thx.
 
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Keep the Jeep lightweight and you can get away with using properly equipped Dana 44's. From what I've learned building a TJ with 40's.

1. A front stretch is mandatory. Even with a proper width axle and correct, combined wheel offset, without a stretch, the tire will be into the rear of the front fender.
2. Highlines & don't skimp. Do the research and see which set offers the most clearance.
3. High-steer and a front stretch, be prepared for some frame notching or a bent drag link.
4. Go with a load-range C tire. Most 40's come 13.5" wide. That's alot of ground contact with a light jeep. I'm fighting a problem popping inner beads (on beadlocks) with a thick sidewall bias-ply 40' aired down low.
5. A 6"-7" rear stretch will definitely require some sort of comp-cut, or at least partial.
6. Plan the build with a cheap "fuse".. A 1310 U-joint at the driveshaft, 35-spline inners with 30-spline outers, or a cheap set of hubs.
7. I'm at 101" and it seems to work within the Northeast "geography"..
 
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sonnyram said:
TJ stretch. I’ve seen someone used a kit to move rear shock mount to get to 106 WB.
Click to expand...

TJ stretch can mean a LOT of things... I cut my frame and moved the arch back 5" & the front axle forward 2.75" so I'm sitting at the "magic" 100" WB... This as I said is what GenRight feels works for up to 40" tires...
But again many here on the forum feel that you need more WB for a 40" tire where the 100" WB is what works for 35" tires...
And again I'm sitting in the middle with 38" tires currently.
I have a 99 Dana 60 that was narrowed to a 65" WMS which is as wide as I'd want to go for my PNW type of wheeling. And my plan is to build a shaved 14B for the rear. Right now I'm finishing working out all the kinks of my rebuild with a Hemi swap and the frame stretch.

And yes GenRight offers a LJ stretch kit plus there are a couple of other companies offering similar kits.

GATORB8 said:
I’m running a shallow shave on a 14B rear and the newer SD 60 front with 1550 shafts.

I don’t think I’ll have a real test for this setup until I swap for more power.
Click to expand...

About the same as what I'm planning... It'll be nice to not have to worry about breaking driveline stuff...

sierradmax said:
Keep the Jeep lightweight and you can get away with using properly equipped Dana 44's. From what I've learned building a TJ with 40's.

1. A front stretch is mandatory. Even with a proper width axle and correct, combined wheel offset, without a stretch, the tire will be into the rear of the front fender.
2. Highlines & don't skimp. Do the research and see which set offers the most clearance.
3. High-steer and a front stretch, be prepared for some frame notching or a bent drag link.
4. Go with a load-range C tire. Most 40's come 13.5" wide. That's alot of ground contact with a light jeep. I'm fighting a problem popping inner beads (on beadlocks) with a thick sidewall bias-ply 40' aired down low.
5. A 6"-7" rear stretch will definitely require some sort of comp-cut, or at least partial.
6. Plan the build with a cheap "fuse".. A 1310 U-joint at the driveshaft, 35-spline inners with 30-spline outers, or a cheap set of hubs.
7. I'm at 101" and it seems to work within the Northeast "geography"..
Click to expand...

Admittedly mine is not a light weight rig but after seeing what some other TJ's weight I'm only 300lbs more than them... Without me in it I'm about 4850lbs which is heavy but with a V-8 & STaK's plus axles and tires isn't bad when compared to those TJ's on 35" tires and stock drivetrain..
 
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Wildman said:
And yes GenRight offers a LJ stretch kit plus there are a couple of other companies offering similar kits.
Click to expand...
I recently came across this company that sells the TJ6 stretch as a kit, including wiring extensions for the fuel pump. The only thing it doesn't seem to come with is brake line extensions and competence!

Jeep TJ to LJ Stretch Conversion Kit – Varozza 4x4 Outfitters https://share.google/ls36uw56nvvMsBCGa
 
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bbaldwin237 said:
I recently came across this company that sells the TJ6 stretch as a kit, including wiring extensions for the fuel pump. The only thing it doesn't seem to come with is brake line extensions and competence!

Jeep TJ to LJ Stretch Conversion Kit – Varozza 4x4 Outfitters https://share.google/ls36uw56nvvMsBCGa
Click to expand...

I "think" the GR kit could be considered a TJ6 also? I honestly haven't looked at it that close since am not sure... The term TJ6 is because you're getting WB of the LJ but the rear overhang of the TJ...

But yes that other kit is COOL and cheaper than the GR kit...

Not sure if they'd been there when I started my stretch if I wouldn't of gone with one of them too.
 
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Wildman said:
I "think" the GR kit could be considered a TJ6 also? I honestly haven't looked at it that close since am not sure... The term TJ6 is because you're getting WB of the LJ but the rear overhang of the TJ...

But yes that other kit is COOL and cheaper than the GR kit...

Not sure if they'd been there when I started my stretch if I wouldn't of gone with one of them too.
Click to expand...

I think the GR parts can be pieced together in a variety of ways. I also don't think they sell the frame extensions. Of course they'll build things if your pockets are deep enough. Like their Tracer chassis that's like 80k for a roller 😳. And let's be honest, if you're buying a Tracer chassis, you aren't putting your old 4.0 in it.
 
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bbaldwin237 said:
I think the GR parts can be pieced together in a variety of ways. I also don't think they sell the frame extensions. Of course they'll build things if your pockets are deep enough. Like their Tracer chassis that's like 80k for a roller 😳. And let's be honest, if you're buying a Tracer chassis, you aren't putting your old 4.0 in it.
Click to expand...

GR has the rear extensions... But it's the complete rear I think with the outboard towers done already... So it's more expensive..

1782311641553.webp


https://genright.com/jeep-tj-97-06/tj-to-lj-frame-kit/?searchid=0&search_query=LJ+st
 
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