I got some work done to my 87tr a few months ago and the mechanic told me I had an 7 1/2 inch, 8 bolt rear with 2:56 gears, my problem is that last week I changed the rear shocks out and while I was under there I counted the bolts on the rear and counted 10 not 8. I'm pretty sure he was correct about the gears because he changed out the speedo gear to get my speedometer working correctly. Not sure what to do now. Is it possible that I have an 8 bolt rear with a 10 bolt cover?? Anyone have a suggestions on how to verify what type of rear I have... Thanks for the help.
Both the 7 1/2 and the 8" rears have 10 bolt covers.
Brian
Get your axle code. It's found on passenger side tube midway between gear housing and backing plate facing forward. All turbos used the 8.5 dia gear and a 3.42 ratio. Early 87 posi was a option and later became standard. 1987 turbos used 4 codes. 2TJ, 3TJ and with posi 2TP, 3TP
2.56 gears where only made in the 7.5 dia gear.
Hope this helps,
Phil
Brian and Phil,
Thanks for the info. I'm in the process of having the trans rebuilt, as soon as that's done I'll tackle the rear. I'm planning on replacing it myself. Do either of you or anybody else have any suggestions on what parts I'll need or things I should look for prior to removing the old one. Thanks for the help. Ron K.
If you do have the wrong rear, and you replace it with the correct one, then you are going to have to replace the driveshaft also. The correct driveshaft is shorter than the one for the smaller rear. By an inch if I remember correctly.
Brian
Talking about axle codes. I was looking under my 84 T-Type and the only codes i could find were stamped on each side of the pumpkin housing right where each axle tube meets the pumpkin shaft. On the drivers side front it had 14075742 and on the passenger side front it had GM2. Not sure if these are part of the axle code or not. Is the actual axle code hand stamped with small letters and numbers on the passenger or drivers side axle tube on the front. Cant seem to locate it anywhere on the axle tubes. Have to take a second look to see if i overlooked anything. The only numbers i found were the ones i noted above. Did they stamp the codes anywhere they wanted on the tubes or was it just in one particular spot? Maybe its possible mine is covered with some debris or surface rust. Thanks for the input if someone can help out.
Ron
Ron, look at the passenger side tube in the center facing forward. The stamp is not very deep and sometimes takes a light sanding and some brake clean to read. For an 84 you are looking for GTP for posi or GTE or 6TJ for non posi. All are 3.42 ratio and 8.50 ring gears.