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Hey all. Working on a 23rd series, Ultramatic, 3.54 rear end. Pulled rhe carrier to replace the gasket, copper wire rings, and clean everything up. Upon inspecting the internals, I found one of the differential gear thrust washers isn't seated properly between the bearing and gear, and on the other side, there's no thrust washer at all. Pinion thrust washers are both in tact. Diff made no noise, and no metal in the fluid. Just seems unusual, and parts book shows each gear having a thrust washer. I do know there were varying thicknesses to the washers, too.

Want to get several opinions here... should I get this rebuilt, or would you run it? Or is it easy enough to to replace the thrust washers, and I could just do it myself? I would think I would just have to follow the manual procedure for up until I hit "Drive Pin Removal," which, theoretically, I wouldn't have to do to replace the thrust washers. Question of course would be washer thickness.

Thanks in advance your advice and experience.

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In your top photo the thrust washers are on the smaller spider gears that run left-right in the photo. Up down in your photo are the side gears, the axle shafts protrude through these and touch against the thrust block. The axles should push against the block directly so I am perplexed by that shim (?) that seems adhered to the side of the thrust block. It should pull right out as the thrust block has plain flat sides. The thrust block should have quite a bit up up-down play in your photo.

The absence of chips or noise tells me the diff is fine. When you reassemble, you will need to pay particular attention to your axle end play as I am guessing that piece of metal was somebody's fix for not understanding how to regulate the play with the shims out at the wheel bearings.

"...The absence of chips or noise tells me the diff is fine..."

... or vibrations.

Awesome. Thanks, guys. Can confirm, nothing seemed particularly unusual from the rear end prior to disassembly. Was smooth and quiet.

In checking for end play, what is the best way to do this absent the gauge mention in the manual?

I like to use a dial indicator with a magnetic base. I stick the base to the axle and let the probe push against the backing plate. Push the axle in, then pull it outwards and read the difference. Or push the axle in and then clamp some bent up piece of steel to the axle with a vice grip or clamp. Clamp the steel so it is just touching the backing plate, then pull the axle outwards and measure the gap with feeler gages.

If it's not broke don't fix it.................but sometimes if things are not correct they should be corrected. I would be inclined to correct this as it seems that with the correct parts/tools this would be a rather simple project, and it would put my mind at ease. Actually what I would really do is whatever Ross says to do!

Well, curiosity got the better of me. I had planned to run it as is and working to just get the end play right, but the new gasket leaked after the third day of having fluid in it (gasket tore, sigh), so, knowing I had to do the gasket again, I took it down and decided to tear into it a little further. Here's what I found with that thrust washer I pulled out vs. a new-old one. Not sure what I pulled out of there was even for a Packard diff, unless it had just pancaked that badly.

So, we'll get those back in spec and do the other checks per the manual and get it re-hung.

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Sometimes it's hard to know how far down the rabbit hole a person should go, but in this case it was good to go a little further. That's a good fix!