Diff fluid advice?

[mujeeper]

Not sure what fluid I got in there right now since I didn't regear them (although I have the receipt SOMEWHERE in the garage....), but I'm opening the front diff to change out seals and wasn't sure what to put back in. I currently have a stock D30 w/ 4.88's & a detroit trutrac. While we're on the subject of diff's, the rear is a ford 8.8 with 4.88's & LS.

While changing the seals, I'm also replacing the hubs. The u joints were recenty changed as well. Gonna clean out the housing reall good, too. Any advice before I begin? I've read several topics on this, & the jist seems to be.

put on jacks
remove wheel/rotors/brakes/hubs/shafts
open diff
remove carrier bolts (being careful to note where they came from, may mark position with marker)
pry out carrier (BE CAREFUL!)
clean the bejesus out of the axle tube & housing
feed rod with socket (or something similar in size to seal) through tube to push out seal. repeat for other side
lube new seal with diff fluid
carefully press new seal in place the opposite way it was removed. repeat for other side
reinstall carrier. torque to spec
reinstall diff cover & wheel/shaft/hub/etc

That sound about right to everyone else? I left out some little steps, but you get the jist.

[Guest]

Im using 90 weight Lucas gear lube in my D30. Depending on your suspension setup you will more than likely need to pump the gear lube in to the fill hole. As for your steps for removal and installation it seems good. Just stay away from brake parts cleaner down there.

[rjh]

Why stay away from brake cleaner down there? When I have my diff open, I spray it out liberally with brake clean to break down the oil that's stuck everywhere, and help flush out any metal shavings. Let it all evaporate good before filling it back up...

[spunebil]

I use 80/130 wt gear lube in axle, the rear ( lsd) will need lsd addative ( course) ;)

[Guest]

Why stay away from brake cleaner down there? When I have my diff open, I spray it out liberally with brake clean to break down the oil that's stuck everywhere, and help flush out any metal shavings. Let it all evaporate good before filling it back up...

I only say that for the fact that there are some grease and gaskets that people use that brake parts cleaners dissolve.

[mujeeper]

I was plannin on cleanin everything out thoroughly with brake cleaner. Everything I've read says to go ahead with it. First time having the diffs open with the new gears installed 2 years ago, so i wanna clean out that fluid. Good point on the gaskets being eaten up. I'll try to avoid the yoke gasket.

Does anybody see the difference in name brands? I've read good things about mobil 1 synthetic gear lube. AAP has it for 10.99. Consider the online coupons, I can get 4 qts for less than 30.

I plan on going with 2 qts if a 7w-90 + LS friction modifier in the rear ford 8.8 & ~1.5 qts of the same up front in the dana 30. Both have aftermarket covers so fill plug is a bit higher (the 8.8 allows you to fill in the front by the ds making life grand). I also heard that with the LS, i need to drive it around in figure 8's to get the fluid in place. Does that all sound right?

[93WHY-J]

I always use Brake Clean on Diffs, been doing it that way for 25+ years. Doesn't hurt a thing. I have never seen it dissolve a gasket or silicone. It does reek havok on rubber gloves though!

[Guest]

Yeah true it does but again some bearings have grease in them and that cleaner eats it up. I wasnt condemning the use of the cleaner just giving a heads up so to speak of the reprocussions of the grease and all that jazz.

[mujeeper]

I have a 95 YJ with vacuum disconnects up front. Does anyone know what (if any) outer axle tube seals will work? I've seen that a lot do not. Some websites say that they do work and others say they do not in the fine print. I'm refering to the seals that keep water/mud out of your tube. Sounds like they only work on TJ's.

[Guest]

None of them work for any disconnect axle, which is what the YJs and early XJs had. Where the disconnect, the shaft is quite large (something like 1.75" diameter) and then it necks down to the standard 27-spline diameter. I don't know why they did it that way, but they did. Either way, the large end would have to fit through the seal, which would then preclude it from sealing against the 27-spline sized shaft.

A fix for this (and for lots of other issues YJ's have) is to swap in TJ shafts. It does require a seal to be installed on the differential that normally isn't there though. The only issue your '95 has that is worth worrying about is the vacuum disconnect on the long-side. The actuator is problematic and prone to failure. Your 95 already has the larger u-joints.

[mujeeper]

Good info, thanks. I noticed that the shafts were different size, but the Superior brand said...

"External seals are highly pliable to work with different axle shaft diameters and allows for long seal life."

so I thought it MIGHT work. I've already had some issues with the vacuum actuator and now, after taking it apart & seeing what's there, will probably end up making my own cable actuated system. I read a pretty good thread about it where you feed in a cable and run a pull cable to the cable to locking handle. All in all, parts are around $50. Cheaper than buying one for around $200.

Any benefits to the TJ shafts? I've never had any issues with my front end so I prob won't worry about it. I swapped out my front u joints about a year back (wasn't needed, but shafts were already out). Those U joints were IN there. They didn't come out easily, or in 1 piece. I pretty much chiseled them out.

Thanks for the input. I'll stick with the inner seals only.

With regards to some pointers when swapping out diff seals, some things to note....
1. buy the seals ahead of time. Autozone, AAP, OReilly's will not have your seal or know how to get it. I thought I was speaking chinese or something.
2. don't forget that after you remove the shafts on both sides, there's still a shaft from the diff to the disconnect that you need to remove in order to pull out the carrier. I'm new to this and a lot of pretty words came out till i realized, DER! shaft is still in half the carrier.
3. the 36mm socket you use to take off the axle nut fits perfect to feed through the shaft to remove the seals. Cleans out the axle too.

[Guest]

The primary advantage is if you break on the trail there are a ton of people with spare one-piece shafts that you can borrow from, but not many with spare disco shafts either intermediate or outer.

[spunebil]

The primary advantage is if you break on the trail there are a ton of people with spare one-piece shafts that you can borrow from, but not many with spare disco shafts either intermediate or outer.

This true for jump seat ( disco side) but drivers side is same :)
Course I carry a spare shaft for both sides ;)
The inner shaft for disco almost never breaks, so I dont carry a spare one ;)

[spunebil]

And if ya carry a spare shaft, the early ones have a larger dia flange ( or vice verce) some are 5 3/4" and others are 6" ! So I only run the rotors for the 6" ;)

And the shafts for a 95 will have 297 u joints instead of the smaller 260 s like am running :)