Rear Differential

[Paradigm49]

Well, it's about that time as far as i'm concerned to change the front and rear diff fluid's and transfer case. However...I've never done it before. I'm always willing to try and learn new things, but some guidance is always a plus I've been looking at different manufacturers for all of the fluids and besides talking to an amsoil "technician" that was an id10t (tried telling me a locking rear differential and limited slip differential are different names for the same thing----uhhh...what?!)

 

 

Regardless. Here is my question. It seems unless i'm completely dense that there is a drain plug on the back of my diff....or is that the magnet? I did see where the fill hole was, but it seems i can fit a 1/2 inch extension into it and move it. Or is it more recommended to pull the diff cover plate out and clean the diff as much as possible?

 

 

 

Any recommendations of gaskets for the rear diff if that is in fact what is needed to change out the rear fluid? I'm not willing to pay for or use GM's grape koolaid smelling gear oil (especially for their price) but i do know that it's not recommended to have friction modifiers in the front or rear diff fluids. I was looking at Amsoil, Royal Purple and Mobil 1 rear gear oils.....recommendations on those?

 

 

 

 

 

Thanks!

[txab]

Draining is accomplished by removing the cover. BUT, remove the fill plug first! You may need to clean the socket on the plug, tends to get crud in there. Any of the gear oils you mentioned will be good choices

[Paradigm49]

Thanks...any recommendations on the rear seal---felpro from advanced auto or something to that effect or get it from the local dealer in the area?....second question...once the oil is drained from the rear diff...i'm assuming using something like carb cleaner or anything of that sort is a bad idea to clean up the rear diff...just let the oil drain as much as possible from everything then put the new seal back on, attach bolts and fill?

 

 

 

 

 

Draining is accomplished by removing the cover. BUT, remove the fill plug first! You may need to clean the socket on the plug, tends to get crud in there. Any of the gear oils you mentioned will be good choices

[Z45]

tried telling me a locking rear differential and limited slip differential are different names for the same thing-

 

A heck of a lot of truck owners believe the same thing, even many mechanics and even a few GM service techs (I met several). Been many an argument on that...

 

The confusion comes from the fact that GM uses option code G80 for both. But limited slips are installed in cars and lockers are installed in trucks.

 

Do not spray any cleaner into the differential gears/clutch pack. Clean cover and gasket surface fine. Note-Clean out the sump of the rear axle, crud tends to accumulate there.

 

NOTE - Make sure vehicle is on a level surface or you will likely not get the correct amount of lube back in or even possibly too much.

[txab]

Thanks...any recommendations on the rear seal---felpro from advanced auto or something to that effect or get it from the local dealer in the area?....second question...once the oil is drained from the rear diff...i'm assuming using something like carb cleaner or anything of that sort is a bad idea to clean up the rear diff...just let the oil drain as much as possible from everything then put the new seal back on, attach bolts and fill?

The fel-pro will be fine. Let it drain then, I'd just wipe out the oil on the bottom. I personally wouldn't use a carb cleaner on it. Put the gasket/cover on, tighten it up. Then fill 'er up.

[Paradigm49]

I mean it's the same basic "premise" as to what it's trying to accomplish but I've had a fix or repair daily with an LSD (which i hated) but mechanically it is incredibly different. I guess i just found it rather humorous---and i'm no mechanic by any means, but i do know the difference between the two. And yes i'm in agreement on the limited slip and the lockers and as to where they are installed. The truck currently has 76,000 miles on it, and of course i grew up with a father that did alot of his own work on vehicles...but never ever touched the rear diff fluid or the tranny fluid (chevy van 20 series---smallblock 350's 3/4 ton) and he never really had problems, but I guess i'm a little bit more proactive about things than he ever was....

 

 

 

So if i understand you correctly, just let all of the oil drain as much as possible, clean the rear cover, put the new seal on, bolts back in and fill...

 

 

 

Front diff and transfer case----just drain and fill, no removal of anything other than the fill and drain plugs...?

 

 

 

Any recommendations on gaskets?

 

 

 

tried telling me a locking rear differential and limited slip differential are different names for the same thing-

 

A heck of a lot of truck owners believe the same thing, even many mechanics and even a few GM service techs (I met several). Been many an argument on that...

 

The confusion comes from the fact that GM uses option code G80 for both. But limited slips are installed in cars and lockers are installed in trucks.

 

Do not spray any cleaner into the differential gears/clutch pack. Clean parts fine.

 

[Paradigm49]

Thanks...seems my posts are now becoming slightly redundant...but thanks for the advice....front diff and transfer case it's just pull the fill and drain plugs, let it drain, plug and fill...?

 

 

 

Thanks...any recommendations on the rear seal---felpro from advanced auto or something to that effect or get it from the local dealer in the area?....second question...once the oil is drained from the rear diff...i'm assuming using something like carb cleaner or anything of that sort is a bad idea to clean up the rear diff...just let the oil drain as much as possible from everything then put the new seal back on, attach bolts and fill?

The fel-pro will be fine. Let it drain then, I'd just wipe out the oil on the bottom. I personally wouldn't use a carb cleaner on it. Put the gasket/cover on, tighten it up. Then fill 'er up.

 

[ybsane]

Thanks...seems my posts are now becoming slightly redundant...but thanks for the advice....front diff and transfer case it's just pull the fill and drain plugs, let it drain, plug and fill...?

 

 

 

Thanks...any recommendations on the rear seal---felpro from advanced auto or something to that effect or get it from the local dealer in the area?....second question...once the oil is drained from the rear diff...i'm assuming using something like carb cleaner or anything of that sort is a bad idea to clean up the rear diff...just let the oil drain as much as possible from everything then put the new seal back on, attach bolts and fill?

The fel-pro will be fine. Let it drain then, I'd just wipe out the oil on the bottom. I personally wouldn't use a carb cleaner on it. Put the gasket/cover on, tighten it up. Then fill 'er up.

 

 

 

 

That's all there is, ditto on the carb cleaner, we use brake cleaner on our differentials to clean them out and it won't hurt clutch packs or those stupid centrifugal weights in the Gov-Lock units.

[jro909]

my advice to you..take it to the dealer, it dosen't cost alot to get it done there and its peace of mind knowing it was done correctley..let alone if it fails you know who to blame