8 3/4 good or bad?

ive got a junk trailer made from a 70 or so sweptline pickup,its been setting close to 20 yrs without being moved,whats the chances the gears are rusty from not being turned in all those years?
its a 741 case

chances are they are still good if it's not humid where you are at

good luck

I think you will be fine. do check the fluid level first

should be fine unless it was open to the elements. I'd probably drain it and refill it with new gear oil.

Does it really matter what condition the gears are in? Its the carrier/axle bearings that are really in play here? I would have to decide whether to run axle first time after 20? yrs to operating temp, and then immediately drain it, or do it before moving. Changing lube regardless would be a must for me.

Just dawned on me, there is no easy way to change the OEM 8.75 lube. Good luck.

Shoot, I'd run it.

R.

Many years ago I was given a complete truck 8 3/4" with 3.91 SG and tires. Rather than tear it apart I decided to leave it complete until needed and parked it along side my shop. Years later I pulled it apart because I had a use for the pumpkin and I found about 1/2" of water in the bottom of the housing...enough to rot away the bottom two teeth on the ring gear.

Although completely sealed from rain, I surmise condensation was the source of the water. Use 'em or lose 'em.

gear lube will not affect the bearings, they require packing with grease...

thats what I'd do. especially since you ain't applying any torque to it. I'd check the fluid & jack it up & see if it turns free & if all good then you're good.

Use a suction pump to remove the fluid if you don't want to crack it open . The cheapo one from harbor freight works good.

20 years sitting out back ... sure run it as is ... go for it , it won't hurt me one bit

It's a trailer. I'd not worry about it at all. You don't need the gear teeth and you won;t hear any noise.

The chances for rust are outstanding for any rear end sitting stationary for 20 yrs, no matter what part of the country it sits in I took a 741 third member out of a 1965 A100 van in 1975 or so and it had sat in that junkyard in Hesperia, CA in the Mojave Desert for less than 20 yrs, it had rust on all the ring gear teeth above the lube line It did wipe right off and it wasn't pitted, I didn't buy it but someone else did and swore it was good later BTW, that one was 741 case with a 3.91 posi I should have bought it

Wheel bearings yes, but the other end of the axle shaft is supported by the differential bearings and they require gear oil.