12 bolt got wet

[1tuff71]

I just had the seals and bearings go out on my 12 bolt and found a bit of rust inside the tubes and also the bearing cage was rusted out ( hard to believe ). Without seeing it is this diff worth saving or should I be looking for a new (used) one.

[Mike C]

Was it completely assembled? Usually all of the machined surfaces are protected by the installed bearings. If completely disassembled and pressure washed I wouldn't be concerned about it unless I found something obviously wrong. Should have seen the last AMC 20 I went through for my '79 CJ-5...

[Chulisohombre]

If it is rusty in there it's possible it was ran really low on fluid and that's how it got the rust in there. The tubes fill with oil to lube the rear wheel bearings because of the semi float design. You must check the bearing surfaces real well. If it was ran low on oil and burnt out the seals it could have damaged the bearing races as well. A machine shop could fix it if it looks bad. Could possibly cost more than buying a new axle though. But finding a correct 12 bolt would be a lot harder than fixing yours. Make sur you check the pinion hearing surfaces and carrier bearing as well of it was ran low on oil for awhile. May need a full rebuild.

[1tuff71]

Not low on lube and it seems to be ok as far as the gears go but the oil seal is frozen in there so I haven't gotten to the bearing yet. It may be really stuck in there too. If that's the case the seating surface for both may be in need of repair. May look for the hard to find 14 bolt that has the 6 lug on it. Think they came in 3/4 ton vans. Had no intentions of spending this much and trying to do it myself. Oh well its history and I'll work through it. Thanks guys

[Chulisohombre]

The 14 bolt semi float six lug came under suburbans and some 3/4 ton pickups. from what I remember. You may need a puller or slide hammer to get to The bearing on your current axle. It's a press fit so it may take some force. Hopefully you
Get it figured out. 40 years of riding on the same bearing and axles something's bound to give eventually. You will need to move the spring perches and shock mounts on whatever axle you find to put under it. Good luck.

[1tuff71]

I know I read in FOURWHEELER or one of the off road mags on what the start and cut off the years were for the sf 14 bolt. Do you recall those years ?

[Chulisohombre]

88-98. The ones before that were all 8 Lug. Van width or 88-91 suburban will be closer to stock but the pickup ones are I believe 1.5 inches skinnier.

[1tuff71]

Thanks everyone.