differential assembly question (1 Viewer)

[thebersrkr]

I have just taken apart the rear diff on my 94 cruiser. I don't have the locker and just replaced the spider gears. When I took it apart I left the third member in place and removed the diff assembly out the back through the diff cover. I am wondering if anyone knows if I need to take the third member off to put it back together. Not sure about the bearing retainer plates and whether or not they can be screwed down or if they need to be torqued or even how I would torque them. Any advice would be great.
Chris

 

[IdahoDoug]

Gotta give the "balls o' the week" award to you, Chris - for tearing down the rear diffy without any clue or an FSM to guide you. Personally, I'd just put the spider gears on and reassemble it as you found it. Unless you replaced the spider gears for whine or wear, in which case everything would likely need to be serviced. I would definitely get the correct reassembly torque figures from someone with the factory service manual (FSM). AFAIK, the only thing you'd need to be concerned about that would differ from simply bolting it back together would be if you disassembled the ring and pinion gears, requiring them to be re-set up for lash, etc. You're not doing that, nor messing with the output shaft with it's need for proper crush sleeve usage, etc so you should be good to go.

Anyone else?

DougM

 

[lovetoski]

Chris - why did you tear it apart?

 

[Cruiserdrew]

If you took off the bearing caps (which you would have had to) then the entire diff-set up except for the pinion position will be incorrect. The backlash is different and the preload on the carrier bearings is changed. These measurments are absolutely critical to a long lived differential. To fix, the diff needs to come out, to take the whole assembly to a diff shop and have them set it up properly. It should not be that expensive, but since it's there you may wish to have the differential rebuilt with new bearings and a new pinion seal. That would addd about $150 to the price, but it's $ well spent if the diff has a bunch of miles. The sad thing is that you could have changed the spiders without changing the diff set-up if you had just pulled the whole housing in the first place. I agree it was a ballsy move-no major harm done, just a bit of $ spent, and a good lesson learned.

I've had my diffs in and out a bunch of times in all 3 trucks. It really isn't that big a deal, but I leave the set up work to the pros. There are several interacting measurments-pinion depth, pinion preload, carrier preload and backlash-that if not set exactly right will cause a noisy diff a rapid wear of an expensive part. Good luck.

 

[thebersrkr]

Hey there! The reason I took apart is because I shredded the right side gear out playing. Got the truck hopping up and down and when the tires were spinning and then came in touch with the ground something had to give. Points to the axles in these things. Anyways, the plan was just pull differential assembly and slide it back in after I replaced the spider gears. Didn't realize I could have done it with them still in the truck. Thanks for input! Chris

 

[CJF]

I've had my diffs in and out a bunch of times in all 3 trucks. It really isn't that big a deal.

This is the next thing I'm working up the nerve to try. Is the FSM clear about do's and don'ts as far as taking out the whole assembly like you're saying, but not messing with the diff setup itself?

Curtis

 

[Cruiserdrew]

This is the next thing I'm working up the nerve to try. Is the FSM clear about do's and don'ts as far as taking out the whole assembly like you're saying, but not messing with the diff setup itself?

Curtis

If you have a later 80 it's conceptually easy. Remove the drive shaft, pull the axle shafts, unbolt the differential from the axle housing, and it will pull right out. Actually, it often sticks and you need to put a bit of pressure on the nose to crack the housing/diff seal loose. Then it pulls right out. Remember it weighs 75 pounds and is very dense and awkward. I always scoot them out onto the bed of the floor jack. Re-installation is the same, but it is very easy to tear the paper gasket between the housing and differential. When you order the gaskets, order a couple of spares. I coat them with Permatex, but you don't have to.