Today I pulled a G80 out of an 88 S15 4X4 Jimmy at a local U Pull it junk yard. The yard charged me $60 cash. I plan on installing it in my 89 S15 Jimmy to replace the open differential. I read all the comments I could find on the G80 and I just want to use for what it was designed for. "Slow Speed Traction Device" To help with getting out of sticky situations. I plan on using my original ring gear and checking the backlash and gear tooth pattern after installation.

It took me about 3 hours to get the diff out. First was the passenger side drum did not want to pull off of the axle. I ended up having to beat it to loosen it up and than I had to pry it off the brake shoes. The drivers side still had the tire on and the yard does not allow jacks but it was resting on a vertical rim. So I went back to the parking lot to get my lug wrench and I was able to get the tire off. Next was the left drum was rusted on to the axle. I beat on and beat on to no avail. I finally got it loose by using an old axle as a battering ram on the wheel studs and the center of the hub. Once I was that far along the 4 cap bolts came out fairly easy. The first thing I did was take the cover off and drained the oil into a aluminum roasting pan from Wal-Mart. We will see how the install goes later on.

 

I completed my G80 swap. I ended up buying new Ring Gear and Pinion set to match up to a series 3 case. I replaced all the bearings including the axle bearings.

 

I have put 100 miles on the G80 with the new gear set. I followed the break instructions to the letter. Diff. is quite and smooth. I have some wet/soft ground at the end of my driveway so I backed out of my shop stopped on the soft ground, gave the car a little gas and both axles locked and pulled perfectly. I will put some highway miles on and no towing until after I reach 500 miles. Once I reach the 500 mile mark I will change the gear oil.

 

Sounds like you did a good job. Congrats

 

Thanks, I was worried about the pinion gear depth as that was the only area I was not sure about. The gear tooth pattern looked ok to my eyes but this was the first gear set I ever changed out. The true test is in the performance. So far so good.

 

So far I have got just over 400 miles on the G80 Diff with a new ring and pinion gear. The car is running great. Next up will be fluid change at around 500 miles or so. I also am going to change my rear drum brakes to disc brakes. I got all the parts from a U Pull it junkyard for around $60. 2 rotors, 2 calipers w hoses, 2 hard brake lines. 2 backing plates with E shoes and short piece of E-Brake Cable.