i am looking to replace the differential in my 85 GS with one off the shelf and was looking through the parts fiche and it seems that theres no gasket between the differential and the axle housing. why is this?

 

The design intent was probably to make for a better mechanical alignment & stronger juncture between the gearset and the axles.

Or maybe it was just cheaper.

Either way, silicone is all thats needed there. It's a low-temp well-machined juncture that operates only at atmospheric pressures, & seals a viscous fluid. Hydraulically, it's a very nearly zero-stress seal.

 

that makes sense. i'll prob just use a thin coat of RTV black then..

 

Yea thats all it takes, nothing too crazy

 

now to instal the thing. the bearings in the current one have seen better days.. i'm going to have to figure out a better oil to use in the diff. book says sae 90. none of that around locally. i might have to order it from redline..

 

I run redline in all my diff's, seems to be working very well so far.

 

thats the route i may go then. redline imo, is a good oil manufacturer. what weight are you using Sean?

 

75W90 is what I use, they say it has LSD additives in it but it still seems to chatter a bit, that won't be an issue for you though as its a non lsd right? BTW did you get my pm about the LE wheels?

 

I looked into gear lubes last time I wandered over to Racing Beat at lunch. Single-weight lube is almost non-existant anymore. They recommended Royal Purple 75w90; I've got two quarts waiting at home for when I get around to changing out my diff oil.

I'll probably try it in my steering gear after I swap it, too - - still cleaning up the new one.

 

One tube of TransX http://www.amazon.com/K-Engine-Posi-.../dp/B00030BFHE then top off with 75/90. This was recommended to me by Stan when he owned SDJ Motorsports. He used it in all his first gen SCCA cars. Great stuff. Its what I use also.

 

thank you guys for the advice!! seems i have a few more choices. i had been running the standard napa brand 80W90 but wanted something a bit better for the long haul.

 

you are correct Sean, not an LSD. i got the pm but i forgot ro respond.. its been along week. i also intend on shipping that lock out to you tomorrow when i'm running erands in the morning.

 

No problem, yea this has been a hellish week here too. As for the oil I'm sure you'll be very happy with redline, but some of the other ones listed as supposed to be just as good, really your choice.

 

not sure what i'll end up going with. i think it'll come down to availability.. i hope to have things buttoned up today. i brought my spare rear end over to the house from my inlaws last night. i'm going to dismantle it this morning and dismantle the current diff and use the best parts.

 

well, i'm currently in the middle of swapping in the new differential. got the new axle stripped down to the two axle shafts and the differential. the old right axle shaft is out and the left one sent me to the hospital as the ratchet with breaker bar struck me above the left eye with tremendous force when the backing plate bolt broke, sending the breaker bar through my eyebrow and into my skull. went to the hospita,l got treated, cleaned, and glued shut. i had some supper and am back to work to pull the old differential and left axle shaft and replace all thrww units. had napa deliver two quarts of royal purple 75W90 to the house for the new axle oil. pics later tonight.

 

i'll upload pics tomorrow evening. i have the newly used diff installed and the right and left axle shafts and installed the brakes on the right side. i have a nasty headace so i stopped..that and i have to get up at 4:40 tomorrow morning...

 

Goddam man you alright? Sounds like your making progress but that injury sounds nasty!

 

Scalp injuries bleed like crazy, too... be careful of concussion, if you're sleepy. I'm sure the docs told you about that. Hope you're allright.

I drained and filled my diff tonight. Royal Purple is in fact purple... and it has hardly no odor to it, unlike traditional gear oil. I may pony up to fill my trans with it, just based on the "doesn't reek" factor.

We'll see how my poor, tired diff likes it tomorrow - - going on a cruise.

 

thank you for your concern. yeah, i'll live.. i opened the cut when i was washing it out and you could see the bone underneath. kinda creepy. now its swolen under the cut and i've had a headache all night. my wife talked me into going to the hospital to have it looked at. progress is slow and that little mishap set me back nearly three hours.

 

i was worried about concussion as i was mildly tired after the incident. it took over an hour to fall asleep last night due to the headache. i only got a few hours of sleep and i have to go to drill with the national guard all day today. sucks. i'd rather sleep in to help the healing process.

keep us posted on how it works in the diff. i have two quarts waiting.

 

Bahhhhh.... if you cleaned it up well, push it back together and squirt some super-glue on it. That was what it was originally designed for, cept people go yeaaaaaa right and have the doctor whip out his "medicinal" grade glue and fix you up for a small fee.

 

i was going to super glue it but it was bleeding too badly to do so effectively. it took nearly an hour for the blood to stop running down my face.

 

Drove the car several hours (up and down twisty canyon roads for about half of it) yesterday in a local meet/event, and I'd say the diff sounded pretty normal the whole way.

I know mine is somewhat worn, and the Royal Purple seemed at least as good at quieting it as regular gear oil.

Nothing asploded.

 

thats great to hear!! i have high hopes for my car's diff. should finish it up tomorrow morning. i'll post some pics tonight after supper.

 

well, i'd been promising pics and here are a few.. though i thought i took more of the differential ready to go in the axle housing and pics with it installed. perhaps because of the whack to the head from the metal pipe, maybe i though i took the pics when in fact i did not.. at any rate here are some pics:

here's the "new" differential pulled from the axle housing waiting to be ceaned and installed:


here' the old diff pulled:


and here's the battle wound as of this morning, most of the swellling is gone which is excellent: