Quick and dirty G80 install on 1031 240 rear.

So, I got a G80 with 4.10 ring and pinion from a 16V car at pull-a-part. Originally wanted to swap ring and pinion into a 1031 housing which had 3.73 open diff. The pinion seal was leaking, so had to remove the pinion nut and flange. Then I thought the 3.73 pinion depth was already set, so to save time, I would just replace the seal and re-install the pinion. I had no new crush sleeve, so I measured the original one, then slipped it over a spare pinion and beat the crap out of it while rotating it continuously. I was able to stretch it out .020", so I reinstalled it and used a tool Jr. made to hold the flange, and with a lot of grunt got it to tighten up. Turning torque checked as tightening continued until in spec. Jr. had already modded the G80 by cutting off the weight.
Then, took the diff with ring gear from 3.73 and oiled up the bearings and dropped it in. Had to persuade it with a few whacks with a wooden hammer handle, but it seated nicely. Installed the caps and snugged them down, then whacked the diff with a rubber hammer about 10 times each way to seat the bearings, torqued the bolts to spec. Turns nicely with a slight drag.
Didn't measure backlash, or gear pattern and don't care. I will put the axles in and put it in the car.
I have a 240 abs axle for the right side and two sets of axles as spares if one breaks. If the diff breaks I will just get a regular diff and weld it up.
Maybe I will have a roller by the weekend.

Yeah, I shade tree'd a junkyard G80 into my 204's rear axle as well. Both were 3.73's, so I left the pinion alone and just slid the G80 in place and closed it back up. I figured the worst case was I crunch up the rear axle and just get another one out of a junkyard. It's been fine for about 5 - 6 years no, pushing 300+ HP through it.

IMO the odds are against you when you start buggering up the pinion area. Bestist/robusist solution is don't touch the factory pinion, throw in your G80 and reinstall the original matched ring gear. Pinion depth will be spot on, all you must do is get backlash set to .006". Throw it in with original shims under carrier bearings, and hopefully your backlash is "close enough". Hell, freeze the carrier assembly and it might just fall in as the carrier preload spec from the GREENBOOK is .0065".

Pinion preload was spot on-turning torque of asssembly was too.
No worries- plenty of spares. If I get a LSD for the flathood, I will take it to the jeep shop- the set those danas all day long.

I put a free g80 into my 1990 240. Had to cut one axle down and forgot to grab the alum g80 cover so my speedo didn't work. Cutting the 48 window g80 tone ring down to 12 window wasn't successful without that cover!!


G80 install album:

http://www.forums.turbobricks.com/album.php?albumid=359

Good luck.

Okay, yeah I once put G80 in rear of 242, then a week later kid shows back up and says hey now put this 3.31 ring and pinion in it. So I did and we drove it, no noise. Didn't check nutin with any measuring nutters. I did ask pappymeagio in his he wanna 15k dream brick thread whatever happened to that 242 and he had my question deleted as he wanna keep HIS dream wanting thread clean..ha.

Yeah I've popped in g80's and rings and opinions never done no checking of nuttin. Never had a problem, except the rubbing of the sensor if you don't swap over the cover or the sensor? I fixed that by putting washer behind the sensor to space it out a little bit. Then it worked and didn't rub my sensory wheel the hard way.

So, I didn't modify the tone ring. I will space the sensor out a bit. I have a T56, and possibly may swap in an 8.8 if I go turbo on the 5.3. All of these could be a signal source for the late speedo.
So, I got one of these to condition the signal-
http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/
Now I can use any source for the speedo signal.

JohnMc said:

Yeah, I shade tree'd a junkyard G80 into my 204's rear axle as well. Both were 3.73's, so I left the pinion alone and just slid the G80 in place and closed it back up. I figured the worst case was I crunch up the rear axle and just get another one out of a junkyard. It's been fine for about 5 - 6 years no, pushing 300+ HP through it.

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Would you be interested in swapping one into my 245 pretty nervous about this on to be honest. Might have to find a local axle shop who is competent enough to complete it. I have no idea how to swap the 3.31 ring gear from my 245 into the 3.73 g80. Sure I can probably figure it out over time though.

There is enough good threads here and in the greenbooks you can read the procedure. so you will have enough info. I've got one to put in as well and am considerng using one of my 3.73 axles instead of the 3.31 my cars has now.

If you're going to pay a shop, you might as well buy a trutrac.

dl242gt said:

There is enough good threads here and in the greenbooks you can read the procedure. so you will have enough info. I've got one to put in as well and am considerng using one of my 3.73 axles instead of the 3.31 my cars has now.

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It won?t be happening any time soon, so I have time to read up.

white855T said:

If you're going to pay a shop, you might as well buy a trutrac.

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Fair point.

I paid a shop to do my truetrac install in the 82 turbo. This was in the early 2ks. They did a great job. The shop had an oven that was used to bake the leaking gear oil off the ebrake shoes. The job was expensive and after reading more on the subject over the years. I will install the G80.

iHateVolvoPeople said:

Would you be interested in swapping one into my 245 pretty nervous about this on to be honest. Might have to find a local axle shop who is competent enough to complete it. I have no idea how to swap the 3.31 ring gear from my 245 into the 3.73 g80. Sure I can probably figure it out over time though.

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The road of least grief.... swap a complete 3.31 1031 from "flange to flange". All the hard work is done; only the grunt work remains. Replace the rear rubber bushings for LCA attachment and you're golden.

DET17 said:

The road of least grief.... swap a complete 3.31 1031 from "flange to flange". All the hard work is done; only the grunt work remains. Replace the rear rubber bushings for LCA attachment and you're golden.

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Like the whole axle? I would, but it?s from a 940 going into a 240, so none of the suspension is the same.

So, after running this for a while, I pulled the T56 for a rebuild and the rear axle backlash is a little loose. I will try to move some shims and actually measure the backlash when I do. No problems, just noticed the driveshaft play is looser than I would like it.