1957 Differential repair / parts ?

[Carcadillac]

Hi, new to the forum, I have a 1957 Cadillac Fleetwood 4 door.  Rear diff input has up/down side to side play, seems difficult to obtain correct parts to rebuild it and or some one familiar with it. Gear ratio 3.3x.  Does it share any parts with chevy models and or does it have a name it goes by?  Or generally direct me to where I can buy a used one? 

[The Tassie Devil(le)]

Welcome to the Forum.

The part you are referring to is called the Pinion, and if it is moving around as you say, the Bearings (Pinion Bearings) are shot, or the Pinion Nut has come loose.

Cadillac parts, in the most, especially mechanical, are totally different to the other makes of the GM Family.

Shortly, someone with more knowledge will come here, and explain deeper.

Bruce.

[J. Gomez]

Unfortunately the MPL does not show/list a part # for the rear axle pinion bearings as Cadillac made the rear axle gear as "none-serviceable" just a full replacement. 

I have an old copy of the BCA catalog that shows these with their part # so you may need to do some searching if there is a match for them.

Good luck..!

[fishnjim]

Find a good differential shop and let them look at it.
Most bearings can be matched by type and dimensions.  The pinion shaft can be reworked, if it's scored.   But I suspect if there's that much play and ran that long to get in that shape, there are other problems back there. 
I haven't had to take mine out yet, so I haven't crossed that bridge about parts.
If you want a whole unit then try "all cads" or some place like that specializing in that era or look for a donor.
My parts list shows the bearings but are N.L.- not listed.  So I suspect they are listed elsewhere.  Shows ball bearings.  Most bearings had numbers on them, so you'd just take them out and look them up in a catalogue.
Probably fits many years, common size.   The 3:36 housing should be stamped "6".
I'd be checking the whole drive line as that much play will transfer to other parts up the line, like u-joints/center bearing.   This didn't happen over night.

[Caddieman53]

As already said, these rear ends were not designed to be repaired. A major obstacle when trying to do a repair, is that the ring gear is riveted on. Making disassembly difficult.

[Carcadillac]

Thanks for the replys, sort out the options go from there. Best case needs a pinion bearing.  I dont know if any crush washers involved.  May have to split it off the axle and take a look. Transmission works" but after drive it, alot of transmission fluid dumps out at torque converter seal.  It was half restored, paint chrome, brakes, engine, interior cosmetics, brake system, before previous owner passed. Doors and fender needs some alignment.

[The Tassie Devil(le)]

I forgot to mention that if the Pinion has been run in its' loose condition for a while, then you will most likely find that the teeth on both the Crown Wheel and Pinion are not going to look very nice.

These "matings" are precision, and unequal wear from misaligned pieces WILL destroy them.

Simply replacing the Pinion Bearings might work, but only if you are very lucky.

Bruce.

[Jim Stamper]

I think you will find it really is " non-serviceable" Special tools are needed that Cadillac never provided the dealerships. Not to say a clever guy can't make workable tools and get something done, but there is zero guidance from the company. The center section was replaced complete, ordered from Cadillac. This is the case from at least mid-30s to early 50s and likely later.

 Find a good center section and replace your old one. Gears worn as described earlier from a worn bearing will never be right gain and they are more trouble than it is worth to change one more than once. An iffy repair is apt to leave you in the lurch somewhere, very un-Cadillac like. My opinion.

       Jim Stamper,  CLC#13470

[Carcadillac]

Iam trying to find a used one, as rebuild seems impossible, most of part yards wont check ratio and or guarantee it works.  Found one from a 1957 Eldorado single carb w/ AC 3.36 ratio, as to weather the pumpkin is a direct swap is unknown, from what generally gather it seems too.  This car is a 1957 60 special w/ AC and 3.36 ratio.

[fishnjim]

I was going to do this before but forgot.
Only thing is if the junk is junk.  Otherwise, I don't see nay issues since there's not many choices and either will be OK.
I'd pull it out and inspect.  I still think a good diff guy could do something or make one that fits from something else or modern.  They do cutting and swops all the time.   My interchange books are down the garage, so won't see it for a day or two.   
Looks for the numbers to tell what you got.

[dn010]

For 1957, the interchange book says 1958-1962 carrier assembly will work. 1957-1964 exc. commercial axle shafts will also work as well so you don't have to worry about swapping those.