Axle differential fluid

I am thinking about pumping out the rear axle fluid without taking the cover off.

anybody just pump out the old fluid thru the filler plug and pump back in new fluid?

That is all my dealer does. That is, suck out the old and pump in the new.

reason I asked cuz I don't think I need to go thru all the trouble to change the gasket and all. And, it makes sense just to suck the fluid out and pump back in new fluid.

Much less pain and not much advantage of taking cover off and replace gasket.

I've always pulled the cover (granted I've had to the last 3 times over the past month due to destroying my cover). Pulling it allows you to check the condition of the gears and and spray everything down with brake cleaner to get out anything not suspended in the fluid. Its pretty simple to do and can be done quickly after a couple times. I just use permatex ultra blue to re-seal it. Its sealed with rtv from the factory, no gasket.

yeah I guess I'll just pump the fluid out and in.

It shouldn't be too dirty anyway.

only 32k

:) I agree with Gizmo, taking the cover off to drain it is the only way you can really tell whats going on. When the transfer case went on mine the chuncks of metal were too big to drain out and the dealer said it was fine. Id look but im nosy. Andie:)

so if you gona take off the diff housing then you have to lower the spare tire and move the swaying bar right?

The bar is right in front of the housing.

:) I take the spare off, then the upper nut off the lateral bar, and swing it down out of the way then just remove the screws on the cover.:) Andie

ok lateral bar ...

and then gasket or permatex?

also, they are selling 1qt bottle with a long tip so you can pump the fluid in thru the filler plug.

would that work or you really need a siphon pump to pump fluid back in?

I've done it with the spare in place and without it there. Easier with it removed though. The latteral bar I pull the nut on the axle side and just pull it back, dont usually remove it. But that normally works better with the spare moved.

Pump is the best way to do it, much quicker and cleaner. Squeezin that stuff out of the bottle takes a while (did it on the trail a couple times with a peice of tubing stuck on the bottle, what a pain).

I tried just a paper gasket and it leaked. Not bad but still leaked. Now I just use ultra blue permatex, not a hint of leak with it.

:) Thats odd, on mine its super easy to squirt the oil in right out of the qt. bottle, the little spout goes all the way in and the bottle can go to about a 45 degree angle. Andie:)

maybe cuz you got an 04 rodeo like mine.

anyway thank you both for your tips.

This is my little project this weekend.

so, permatex is the way to go instead of a real gasket.
move lateral bar by loosening upper bolt ( I didnt notice that but I'll look for it, all I saw was a huge bolt attached to it )

we'll see what happens.

oh and the Supertech diff fluid is great right?

I used Valvoline SynPower in mine the first time I did it. Now I have Royal Purple in both. Costs about the same or a bit less depending on where you get it. Neither needs extra addatives for limited slip. I have no complaints about either. Dont know about supertech.

it says on bottle "no additives needed" because it's equivalent.

I come to trust supertech because I've been using their oils for my engine and transmision.

How you do you take the lateral bar off so you can get to the diff housing?

It's the big nut right?

It seems that it so stuck even a breaker bar couldn't loosen it

where is the upper nut ?

:) Yes but u only have to remove the upper nut and slidle the bar off the stud and then swing it down. The lateral bar is right in the way romoveing the cover. You must just have a thoght one. Try spraying it with some pb blaster or something or get a longer cheater. Andie:)

:) I take the spare off, then the upper nut off the lateral bar, and swing it down out of the way then just remove the screws on the cover.:) Andie
Where is the upper nut of the lateral bar?

All I see is a long metal bar with 2 19mm nuts at 2 ends and it's stuck.

are those what you're talking about?

I am afraid I tried to loosen the wrong nut.

To disconnect it from the axle (drivers side) like I do just remove the nut and pull the bar towards the back. Its torqued around 100 ft lbs and probably never been loosened on yours so could be tough.

As a side note, I just added some LSD addative to mine today. Seems royal purple doesnt have enough in it. My rear axle was making horrible noises this weekend and I'm hoping its just the LSD clutches not having enough addative.

To disconnect it from the axle (drivers side) like I do just remove the nut and pull the bar towards the back. Its torqued around 100 ft lbs and probably never been loosened on yours so could be tough.

As a side note, I just added some LSD addative to mine today. Seems royal purple doesnt have enough in it. My rear axle was making horrible noises this weekend and I'm hoping its just the LSD clutches not having enough addative.
ok. I just went out and gave it alot of wd-40

I do have a torque wrench that goes up 150lbs.

Kinda suck when you are under there and no room to push or pull

just that nut right? you need an extra wrench to hold the bolt on the other side?

i could loosen the nut on the driver side but the one on the passenger is a pain. Still trying

I dont know how they put them there in the first place

is it because you're not suppose to loosen it on the passenger side?

I've never messed with the passenger side so dunno. I've always just done the drivers side and pulled the bar back a bit. Dont really have to pull it off all the way even, just a bit will give you enough room to get the cover off I think. Dont remember how far I had to pull it with the stock cover, I've been using standard D44 covers since the first time I changed the fluid.

On the drivers side just need to remove the nut. The 'stud' the bar attaches to is welded or pressed to the bracket so should never turn.

ok but the passenger side seems like you got to hold the bolt from the inside but no space to do that anyway.

It couldnt be much tougher than driver side and i was able to loosen driver side after wd-40 easily but not passenger side. kinda different.

anyway, there are blude, red, black rtv and ultra too.

any would do fine? why are there diff color?

Red didnt really work that well for me for some reason. The ultra blue is working really well and even with my very damaged cover got me back from Moab plus a couple of weeks without a bit of leaking. I usually use ultra blue for everything. I have also tried just paper gasket and paper gasket with red stuff, both either leaked or slowly seaped so I gave up on gaskets and just use RTV now like the factory did.

Here is a pic of the damaged cover. As you can see it had to seal a pretty uneven surface.
http://i30.photobucket.com/albums/c337/Gizmo420/Moab%20ZuZoo%20X%202007/Img_0456.jpg

wow that looks pretty damaged.

what did you do to get that? lol

ok ultra blue then.

I still dont get it why the passenger couldn't be loosen. The 'stud' moves I think.

wow that looks pretty damaged.

what did you do to get that? lol

It happened twice in 3 days in moab. The bent up part on the left of the pic is actually the bottom of the cover. I bent the bottom 'lip' out a bit on one trail, got it pounded back into place good enough so it was just a drip and finished the trail. Pulled the cover off, straightened it, and resealed when I got back to the hotel. 2 days later got it caught on a rock again only this time it bent it out then up so it was 180* from the way it was supposed to be. Some creative use of blue stuff, vice grips and hammer got it sort of in position and slowed to a fast drip. Put in some of the old oil from 2 days before (poured it into empty water bottles for later disposal). Managed to finish the trail and get back to camp. Took it back off, straightened, resealed and it heald great for 2 weeks till I got my new cover. I now have a Tera Low ductile cast iron cover thats 3/8" thick and weighs 10 lbs!

The dent just to the right of the bottom lip isnt supposed to be there either. The rock smashed it into the ring gear and abs sensor ring. You can see where they ground into it a bit.

well I did it. I pumped out the old and in with the new of supertech 80w-90 gear fluid with no LSD additive.

It seems to be ok so far.

I used a siphon pump to suck it out. I got lazy so I didnt open the housing.
I just moved the hose around until I just pumped air out of the housing.

Maybe next year I'll do that.

Anyway, I was able to suck out almost 2 qts which is pretty close to the spec.

The old fluid is sooooooooo dirty. Glad I changed it even though I might leave some metal shaving but it's better than nothing

By the way, how do you tell if your rodeo has limited slip diff ?

Is there a tag or something?

Look on the firewall on the drivers side (in the engine compartment). Should be a tag there with option codes. LSD would be a code of G80. Should be a tag on the rear diff as well but they often get broken off or lost. Would be a black tag on the drivers side with the gear ratio and an orange tag on the left side that says to use LSD addative.They are just held in place by the diff cover bolts.

One way to be sure is to jack up the rear and spin one tire by hand. If the other tire spins the same way then you have LSD, if it spins the opposite way then you dont.

Getting ready to take my cover off AGAIN! I think the lack of enough addative in the royal purple lube killed my LSD. So I'm looking at putting in a no-slip locker.

I've seen no tag whatsoever attached to the diff bolts. The bolts are all by themself. I just did the fluid change today so I am pretty sure of no tag.
Unless they engrave them on the axle it self.

I'll look on the engine compartment.

Come to think of it, I might not have LSD.

Cuz I put in cheap Supertech GL-5 fluid and no extra additives and I've been driving around all day and no noise no vibration.

I used to believe all rodeo 2004 have LSD by default.

I guess not

:) Mine doesn't, Im looking at that electic locker by Auburn if i can get a definative answer that one will fit. Mine just has a metal tag on one of the diff screws that says 4.30. Gizmo are you sure it was the lack of additive in the royal p or did u burn the clutches when you did the damage to the cover? :) Andie

Come to think of it, I might not have LSD.

Cuz I put in cheap Supertech GL-5 fluid and no extra additives and I've been driving around all day and no noise no vibration.

Even being screwed up mine sounds fine when just driving. Its only when I get all the load on one wheel that I hear it. If you get one rear wheel in the air and it sounds like gears slipping thats the LSD clutches chattering. If you never hear a chatter then I wouldnt worry about addative.

I dont think the 2wd 2nd gens came with LSD unless it was ordered that way. Its not engraved on the axle, just tags on the diff cover bolts. Like I said, they could have been broken off or lost, or maybe not used in later years.

I'm almost positive its the royal purple causing the problem now. Everything was fine when I was using valvoline synpower before I messed up the cover. Since the royal purple was a little cheaper I started using it then and thats when the chatter (chatter doesnt quite describe the horrid noise though) started. I have since added a tube of LSD addative and its a little quieter but still doing it and the LSD doesnt seem to be working right. I did some googing and found posts from other ppl with the same experience. Even to the point of the clutches being destroyed.

I would love an electric locker but dang are they expensive. Probably have to have it installed and the lash adjusted as well so labor costs on top of that. Thats why I'm going with the Powertrax No-Slip (http://www.powertrax.com/noslip.htm) just take all the guts out of the LSD carrier and this goes in its place. Indy4x sells them for about $435. Its a full locker though so driving in winter is going to be interesting.

:eek: I did alot of test driving on friends trucks this winter and the one with the full locker I promply put the side into an aspen. It was just too scary for me. But I think the Auburn one sounds great. limited slip to full lock. Its the way im going. Just have to find one that fits, Auburn says they have no application for my truck. I understand it will have to be set up by professional.:) Andie

Seems odd they dont show one for an Isuzu unless they just dont know about it. Offer to test fit one for a big discount LOL. I know with the locker I'm looking at its the same part number as for a Jeep D44 30 spline with LSD. Dont know how much different over all ours are from the ones in Jeeps.

I think all 4WD rodeos come with limited slip diff as standard.

I think all 4WD rodeos come with limited slip diff as standard.

Thats what I thought too, but have seen posts by a couple ppl (I think Andie was one of them) that said theirs doesnt have LSD. So now I just tell ppl to just check it.

:) Yes mines deffinately open. Andie:)

yeah I guess mine is open too. Until now, I had been thinking mine has LSD because when I bought it, the specs said LSD in there.

Anyway, now I know why it squeals when I make a turn in the parking garage to the next level :)