What is the best way to change the rearend diff fluid? Just pop the cover and let it leak all over my face? (just like doing trans fuild woohoo!! LOL). Dont know of any covers with drain plugs anyway. After its drained, re-assemble, and fill it till it starts to spill out right?

Also, isn't there a special fluid us 9 bolt guys gotta use?

I think its time to service my rearend ....

 

I haven't read through the tech article in a while, but that's basically it. I don't know how easy the cover gasket is to get, I'm planning to use rtv and letting it dry overnight before filling it up with royal purple full synthetic. The bottle claims it already has the posi additive, so I won't be adding anything else.

Then there is the part about shims, but I have never serviced any type of differential before and won't have the time to properly learn by wednesday. Gotta make sure I get those calipers rebuilt in time.

Anthony, most of my suspension bolts are pretty bad but I can reuse them if there's nothin' else. There's another 24mm bar in my garage but those don't even have the clamps. It's not a big problem if you don't have any lying around.

Scott

 

Yup you got it. Crack the cover open & let it all drain ("spill!") out.
Put the cover back using rtv to seal it, since there is no servicable replacement gasket, & refill it with 75w/90 (aka=GL5) until it spills out from the fill hole. Technically you are suppose to add some limited slip additive & some companies actually claim that they have limited slip additive mixed in with their gear oil.

Back when I was still working at Jiffy Lube we added the additive ourselves when doing a rear diff service. It was in a small bottle but I forget which brand it was that we used.

Hope this helps

Anthony

 

FYI the 9-bolt gaskets and diff covers are not available new anymore. When I changed the lube in mine, I cut a new fiber gasket from flat stock. If you want to cut a gasket ahead of time, I have an extra diff cover that makes a good template.

If you're referring to shimming the rear PBR calipers to center them, Ed Miller says it's not necessary, just ensure there's no binding in the hardware so the caliper can self-center. The shims were used during 10-bolt to 9-bolt PBR conversions.

 

Oh, I was unaware of needing shims for the conversion. I was referring to the differential itself.

 

Why are you removing the differential?

I thought you were simply going to unbolt the old rear and bolt in the disk one...

 

Nope, just peaking inside. Thought Shawn might want to do more than that if his posi isn't at 100%.

Just pokin' around and changing the fluid. Damn, I forgot to lay the RTV tonight. I'll have to do it first thing tomorrow morning.

Today was extremely unproductive for me. I wish my teacher would let me take care of this my own way.... Especially with only two days remaining.

Scott

 

I'm still looking for those u-bolts Scott It's driving me nuts cause I can't remember where I put them. I think I placed them somewhere & then my dad moved them somewhere else since he was cleaning up around the area. Nothing ever gets thrown away at this house (pack rats lol!) so it's around somewhere. Wish me luck!

 

I managed to get my u-bolts off without damaging them. The rest of the suspension, however....

Don't know why my teacher wants me to take everything apart so soon. I wanted to let the PB Blaster work its magic over the first two nights. Spent all afternoon trying to take out (unprep'ed) rusted bolts.

 

The rotors are RIGHT at the edge of machinable. Forgot what my readings were, but I calculated as little as .009" of cuttable metal to up to .012". I really wanted them cut today but my teacher had other plans. Need to know by tomorrow if they can squeeze by or if they need to be replaced (by Wednesday).

I'll post the specs along with the scans in a little while on the PBR thread. It's taking a long time to get clear images because of the crinkled, dirty paper.

Scott

 

Shoot I'm sorry man. I didn't know the rotors were that cut down already. I hope you can still cut them.

 

No worries. They'll be cut regardless. I need the "credit" and if I'm lucky I can save 'em.

Unless they turn out to need a lot shaved, I'm going to just cut them until they are straight and use 'em anyway. As long as they are within the 'discard' specs I think I'll be fine. I'm planning to change all the rotors next year anyway, the fronts will be past the 'machine to' specs before the pads are gone also.

 

http://www.partsamerica.com/PartDeta...ype=95&PTSet=A

This means CHECKERS too.

Just a correction, there is a gasket, and cheap too.
I do recommend the rtv idea though.
shawn (OKINAWA) AKA: SHAGGY

 

Rotors were pretty overcut... had no choice. I'll change them out EARLY next year I guess. I've got a few thousandths before the 'discard' spec.

I RTV'd it up last night, forgot to check on it today. Should I have torque'd the bolts when I laid the bead or just snugged them and waited for it to set? If I did it wrong I'd rather redo it now before I put the synthetic into it.

By the way, I don't know rears too well, but it looked awesome in there. I doubt my pics will turn out too good, but we'll see later tonight.

Scott

 

I have a set over here in Okinawa, that came off of the donor 1989 IROC, and i had cut....... Now they are just under the limit. I was tempted to ask on the brakes board if they would be ok for in town driving, but didn't want to hear folks calling me names cuz of a basic question.

I really need to touch base with ED, to make a checkers run for me. I am looking to "freshen up" the calipers and pads. I tell ya the POR -15 is the shiz-nit on diffs. Mine looks great, just needs brakes and in it goes.
shaggy

 

I don't see a problem for light braking as a temporary solution. If you are talking about the fronts also then you should rush those rotors in.

What do you need from Checker? They probably won't have it.... (Check some of my posts in Ed's 'PBR' thread.)

Scott

 

Oh and what gears are in it anyhow?
I have procured a set of 3.45, and a set of 3.70....... but now need a 3 series diff. I have conections down-under, i just need to get a part number.
It really sux cuz the donor car had 30k on it, and the posi is tight, but the gears won't go. A wasted 2 series posi if you ask me!!!

 

I read the PBR post last night. WOW, AND FRIGGEN WOW. That is all great info, and easy access for you guys.

 

I'll try to post more!

Here's the best pic of the 9-bolt... not very good at all.

Scott

[edit:] Deleted pic, switched computers so I can't upload another that was also dark.

 

do you rememeber the gear ratio?

 

3.27

 

sweet

 

The 9-bolt on the '86 that this thread used to be about probably had a 3-series. Anyone know if it's still there?

Did Shawn or anyone ever find out a ratio?

Scott

 

U might wanna delete that other pic, it's real dark. Even blasted the gamma to pump the midtones and didn't get much. Aim the camera so more light goes in there... Whew, this is getting really exciting now!

 

Thanks Ed! I had a drop light over it, but the place just isn't well lit and my stall is the farthest from outside. There wasn't much to see anyway, so I didn't go crazy trying to get pics. I just wish I could hold my light camera still enough to get clear shots. The rest were very blurry.

Scott

 

I never ended up going back to that car at the Shafter yards. I read that Rainman needed a T5 so I left it for him. I figgure he prolly needs it more than me since its for his daily driver. I would be putting it in a drift car and blowing it up anyway. But that rearend is still game, I say go for it Scott. I'm betting its a 3.45 ratio since the car is a T5. The other 3 series ratio was for the Auto's (well according to the tech page, which was wrong to begin with LOL).

Hey dont throw away that 2 series diff Shawn, I'll buy it from you.

 

How's my spray paint job holding up on your diff Scott? lol! The insides look pretty clean to me in the pic. I'm getting excited too now!

 

Anthony, I managed to put it in without takin' too much of it off. Although, to bleed the driver's rear I just let it spray onto the panhard mount. It took me a couple of minutes before I realized what I did, hehe. Still looks good though, I appreciate it.

As far as the '86 9-bolt, it's still there (as of last friday) and it's a 3.27 posi. The T-5 is also there. I might try to head over there on Sunday to pick up some 'vette wheels (that have been there since last summer) and I might take those WS6 swaybars unless someone else wants them.

If I can't make it on sunday (or, more likely, if I can't get someone with a military ID to come with me) then I'll head out there next weekend. I don't know which days count of holidays.

Scott