Re: 8 3/4" Third Member Swap Questions?

Done, almost.

I checked the axle free play, it was 0.010" perfect. However the locking tab was not installed correctly, I corrected that when I checked the free play. The lug nuts on both of the rear wheels were just beyond hand tight. I suspect that was from when it was on the lift and when the car was put down he never went back and tightened the lug nuts. The pinion seal is leaking. I had him install a new seal when he swapped the 3rd members, he said the pinion yoke was pitted and installed a sleeve, looks like it will be going back in to have it fixed. When I talk to the shop I'll mention that I can get a new pinion yoke if that is the problem. Per Doctor Diff it is the same as the 742 uses.

I try to avoid having someone work on any of my old cars however I was not ready to change the 3rd member with the car on jack stands. I've done it enough when I was younger.

However I don't trust shops. I double check everything they touch.

Thanks to all of you who commented.

Dennis C.

On Tuesday, August 20, 2019 at 8:08:53 AM UTC-7, dennis.1963ply wrote:

Thanks Nick,

I'm learning more about differentials than I will remember when I'm done.

I'm going to check the axle free play (bearing preload) today. I will know then if installing the older 985 3rd member was a mistake. The following I found after making the sway:

There was a difference in thrust blocks prior to 1964 that make center section interchange, as well as axle interchange problematic. The thrust block, or "axle shaft thrust spacer", it thr block that both left and right axles butt up against inside the center of the differential. Prior to 1964, all open differentials used a thrust block was approximately 1/8" to 1/4" thicker than units made after 1964.

Thanks again,

Dennis C.

On Tuesday, August 20, 2019 at 6:39:53 AM UTC-7, FuryUs63 wrote:
Gary,

The (985), 1634985 was the early (742) 2070742. The (985) casting was used 57-64.

Nick T.
FuryUs63

On August 19, 2019 at 11:07 PM 62-65-mail...@xxxxxxxxxxx wrote:

Not remembering a 985 8.75. Confusion is contagious. :)

Gary H.