Changing rear differential gasket

[AWOL Marine]

I have a very slow drip coming from the rear differential gasket and am wanting to fix it. Do I need to get the rear off the ground to change the gasket? Will I need to remove the drive shaft?

Also, any tips you could provide would be awesome. Thanks to all. Your a great group.

97 SR5 3.4 2x4

 

[Pikeman]

If you are talking about the gasket between the 3rd member and the axle housing you will need to do a few things.

Raise and support rear axle on jack stands, unbolt driveshaft, remove tires, drain differential(can be done before jacking up), unbolt and slide axle shafts out, remove 3rd member, clean gasket surface and then reassemble with new gasket. It sounds like a lot but it really isnt that bad. Be carefull when removing and replacing the axle shafts to not damage the seal.

 

[AWOL Marine]

Crap, I had no idea. Thank you VERY much for that post. Is there a write-up on this board? If not I may need to add one.

 

[the great him]

you also need to unhook the brake lines

 

[J-money$$$]

And just use Ultra Grey silicon gasket maker. A nice even coat (go around all the studs) will do the trick. Just give it some time to dry before filling it with oil. No write up. If you want try looking a lockright locker install. It should show the steps to get the 3rd out. Its easy and self explanatory. Drain diff. Undo the 10mm fitting for the brakes on each drum. Get the rear end on jack stands. Pull the shafts. They only need to come out about 4". all the way works too. But if you choose to not remove them all the way you need to make sure you rest the drum on something to not damage your axle seals with the weight of the axle. Undo the nuts on the 3rd and GET READY!. Its a heavy POS. I would say 50 lbs. Its a lot to come down onto you.

Another note. You need to clean both mating surfaces really good. And your going to knock some stuff into the axles housing so clean that all out too. Brake parts cleaners is good. Have fun. Should only take an hour or two if you really take your time

 

[Stick Figure]

Do yourself a favor and pick up some new hardware before you get started. Unless this isn't your only vehicle and you can afford some down time. The last one I did, everything was fine until I put the torque wrench on them, and then one by one the nuts lost the threads on the inside. Made everything take a lot longer than it should have.

 

[Big John]

Do yourself a favor and pick up some new hardware before you get started. Unless this isn't your only vehicle and you can afford some down time. The last one I did, everything was fine until I put the torque wrench on them, and then one by one the nuts lost the threads on the inside. Made everything take a lot longer than it should have.

Dont scare the dude. This is VERY easy to do. Follow the steps Pikeman & "j" gave you.

It's literally 4 bolts, a brake line, and e-brake cable per side to get the shafts out.
Then… Take off drive shaft. Unbolt the diff, clean surfaces, put sealant on, reverse the take apart procedure (i usually tighten the diff in a star pattern), fill with oil, bleed brakes, done.

The only things you should need is gear oil, brake fluid, sealant, 14mm, 12mm, and 10mm wrenches, and maybe a pair of pliers for the e-brake cable.

If you've never done it, it can be a little intimidating but this is one of the easier things you can do on your rig and in the end you will be surprised at how easy it really was.

 

[Nelsonmd]

Dont scare the dude. This is VERY easy to do. Follow the steps Pikeman & "j" gave you.

It's literally 4 bolts, a brake line, and e-brake cable per side to get the shafts out.
Then… Take off drive shaft. Unbolt the diff, clean surfaces, put sealant on, reverse the take apart procedure (i usually tighten the diff in a star pattern), fill with oil, bleed brakes, done.

The only things you should need is gear oil, brake fluid, sealant, 14mm, 12mm, and 10mm wrenches, and maybe a pair of pliers for the e-brake cable.

If you've never done it, it can be a little intimidating but this is one of the easier things you can do on your rig and in the end you will be surprised at how easy it really was.

Hey, don't make him think it is too easy though, there are some pitfalls...

OP, be careful of the torque you put on the carrier bolts (I think there are 10 of them or so), the FSM I have gives the wrong torque spec (too much). search here for threads about it, I stripped some nuts too because I used the FSM torque and it was way too much. Someone here gave the right torque, but I don't remember what it was.

You should get new nuts and washers as they are 1-time use components.

Before you go tearing it apart though, make sure all the current nuts are torqued correctly. A friend of mine had a slow leak too, took it to a shop, they said axle leak (from rust) and the vehicle wasn't worth the work it would take to fix it. I found that the bottom 4 nuts were loose, so I tightened them, and the leak was gone. Maybe your nuts are just loose.

Anyway, good luck. It really isn't that hard like Big John says, but you do have to pay attention.

 

[cordrayj1]

i second the RTV. thats all i use. i have a stud that is stripped right now near the top. havent had any leaks. that rtv is way stronger than you think.

 

[AWOL Marine]

All great posts, thank you. Its not loose bolts, checked that. Sounds like a fun project as long as nothing is rushed. Also going to be a good opportunity to get to know my runner a little better. Only had her for a week and she is already worlds better then my 99 Cherokee. God I hate that Cherokee.

 

[cordrayj1]

when you look at the diff, you will see the attention to detail toyota went through to ensure their products dont fall apart. lots of safety fasteners. you wont find a whole lot of that on a jeep.

 

[Mr. Leary]

several detailed writeups in the "tech writeup" sections on Yotatech.

 

[Ghostrider]

If you have the time you might as well do the axle seals since you will have the axles pulled out.

 

[J-money$$$]

If you have the time you might as well do the axle seals since you will have the axles pulled out.

pulling the axles out takes 20 minutes. Its not major. I think leave the axle seals till they leak. Unless your having leaks anyways then its a good combo job

 

[Big John]

Hey, don't make him think it is too easy though, there are some pitfalls...

OP, be careful of the torque you put on the carrier bolts (I think there are 10 of them or so), the FSM I have gives the wrong torque spec (too much). search here for threads about it, I stripped some nuts too because I used the FSM torque and it was way too much. Someone here gave the right torque, but I don't remember what it was.

You should get new nuts and washers as they are 1-time use components.

Before you go tearing it apart though, make sure all the current nuts are torqued correctly. A friend of mine had a slow leak too, took it to a shop, they said axle leak (from rust) and the vehicle wasn't worth the work it would take to fix it. I found that the bottom 4 nuts were loose, so I tightened them, and the leak was gone. Maybe your nuts are just loose.

Anyway, good luck. It really isn't that hard like Big John says, but you do have to pay attention.

Sorry Nelson but pitfalls are a rarity in this one.

There are potential pitfalls to every job, but telling the guy he needs all new hardware before he even starts the job is simply wrong. If there are no problems with the studs or nuts, leave them alone. There are plenty of Toyota's out there that are 25+ years old running that same 25 year old hardware with no issue. Even after having several diff jobs done in that time.


I've also found that torque wrenches can sometimes cause more trouble than they save. Especially on small stuff like this. When was the last time your torque wrench was calibrated? (had mine done 4 mos. ago) Are you using a quality torque wrench? I'm using a Snap-On torque wrench and still don't completely trust it to torque small stuff.

When you're talking anything under 50lbs or so of torque, there's a lot that can go wrong if that torque wrench isn't reading correctly. There are a lot of components that should be torqued but for me this ain't one of them. The proof is in the pudding… The only people that have chimed in here with a bad experience replacing a diff are the one's that tried to torque them.
And… Since you are educated enough to "call me out" directly, I'll assume that you know that ANY contaminates such as oil, dirt, lock tight can change torque readings quite dramatically.
There is a time and place for torque specs, but IMO a good portion of them are to keep some gorilla from putting a 3ft breaker bar on a 8mm bolt.

I say tighten the bolts in a "star pattern" till you get that warm fuzzy feeling with nothing bigger than a 3/8 ratchet and you'll be fine. Go around the diff a couple of times as it very well may "suck in" after you tighten the first few bolts and they will be loose again by the time you get back to them. Tighten the axle nuts a couple times as well as they usually suck in too.

This is an easy job

 

[Nelsonmd]

Sorry Nelson but pitfalls are a rarity in this one.

There are potential pitfalls to every job, but telling the guy he needs all new hardware before he even starts the job is simply wrong. If there are no problems with the studs or nuts, leave them alone. There are plenty of Toyota's out there that are 25+ years old running that same 25 year old hardware with no issue. Even after having several diff jobs done in that time.


I've also found that torque wrenches can sometimes cause more trouble than they save. Especially on small stuff like this. When was the last time your torque wrench was calibrated? (had mine done 4 mos. ago) Are you using a quality torque wrench? I'm using a Snap-On torque wrench and still don't completely trust it to torque small stuff.

When you're talking anything under 50lbs or so of torque, there's a lot that can go wrong if that torque wrench isn't reading correctly. There are a lot of components that should be torqued but for me this ain't one of them. The proof is in the pudding… The only people that have chimed in here with a bad experience replacing a diff are the one's that tried to torque them.
And… Since you are educated enough to "call me out" directly, I'll assume that you know that ANY contaminates such as oil, dirt, lock tight can change torque readings quite dramatically.
There is a time and place for torque specs, but IMO a good portion of them are to keep some gorilla from putting a 3ft breaker bar on a 8mm bolt.

I say tighten the bolts in a "star pattern" till you get that warm fuzzy feeling with nothing bigger than a 3/8 ratchet and you'll be fine. Go around the diff a couple of times as it very well may "suck in" after you tighten the first few bolts and they will be loose again by the time you get back to them. Tighten the axle nuts a couple times as well as they usually suck in too.

This is an easy job

I never said it wasn't an easy job. And I understand very well the need for calibration of a torque wrench (not that I actually calibrate mine, it's a home depot torque wrench). I know you have a shop and have better tools than any of us, and have probably done this more times than any of us, but that is kind of the problem. For a "professional" this is as you say a "VERY easy job", but for a novice that may not be very mechanically inclined or have no experience, it is not so simple. You mentioned several points that are easy/assumed when you have experience, but are completely unknown to a newbie:

1. The need to use a torque wench, or just "Good-n-tight" it with a 3/8's socket. That's judgement.
2. Tighten in a star pattern. A basic principle, but not immediately obvious.
3. tighten multiple times. Again, basic, but not immediately obvious.
4. you don't need to replace the nuts and washers every time. Judgement call based on application and condition. Nuts and bolts are pretty cheap, so I prefer to replace them. If Toyota know's their nuts and bolts (which I am more and more convinced they don't), then they should be getting some strain hardening every time they are torqued on, so they aren't really infinitely reusable. It's a very minor issue, but between that and rust, I like to replace them.

These are all things that a newbie trying to follow the FSM (which is a good practice) won't necessarily know. It's good that you have said them now, because they often get overlooked in walkthrough's (they are usually assumed knowledge), but to me, these kinds of unknowns, along with the fact that the FSM gives way to high a torque spec for these nuts, makes it more than just a "VERY easy job" for a newbie.

 

[rediranch]

Rusty diffs

I'd like to add a few points to all the above.

Yes, this is a pretty easy change (gasket), unless you live where salt is used on roads for snow.

I bought a 98 (have a 99) that was originally from the East coast (I am in CO) and the diff was gone so I needed to get everything replaced. I am not confident enough to do the gearing, but I knew how to pull the 3rd member out so I could take it to a shop to have it rebuilt, saving the labor of pulling the axles and 3rd member.

I found that the 3rd member was rusted to the top of the axle housing. All nuts off, and the thing would not drop.

The muffler was rusted badly so I cut it off which gave me a lot more room to work.

I ran a string around the rubber brake line and diff breather on the top of the diff so that I could tie it off, pulling it away from the axle housing. Then I used a propane torch to heat the axle housing - forcing the metal to expand on the housing but not as much on the 3rd member; then did the reverse, trying to break the rust apart.

Then I used a brass punch on the top of the 3rd member, trying to bust the rust loose.

Finally it broke and dropped the 3rd member.

Also, when I drop 3rd members, i have an empty plastic oil tub (the kind with plugs) underneath of it to catch it in case I lose my grip.

If you need to replace the studs due to messed up threads, after you get the 3rd member off put 1 nut on the stud far enough so you can put a 2nd nut on after the 1st. Using two wrenches, tighten the 2nd nut against the first, then wrench the first nut off - that will force the stud to turn and you can remove and replace from a Toy dealer.

 

[DustinJoints]

If you need to replace the studs due to messed up threads, after you get the 3rd member off put 1 nut on the stud far enough so you can put a 2nd nut on after the 1st. Using two wrenches, tighten the 2nd nut against the first, then wrench the first nut off - that will force the stud to turn and you can remove and replace from a Toy dealer.[/QUOTE]

Great tips bro thank you

 

[DustinJoints]

:bolt::bolt:I'm looking forward to changing mine now after hearing from you guys and I wont be using a torque wrench, good and tight sounds like the proper torque spec to me.

 

[Wakko]

Anyone know how to change the rear diff housing? I've got a leak where the housing connects. Is this basically the same as the 3rd where it's just a sealant or is there a special gasket I need?