Pinion Seal Leakage

[CYi5]

After having my inner, outer, and pinion seals done, not to mention the wheel bearings, my pinion is leaking once again. Without going into too much detail on the problems with the other seals, this will be the 3rd pinion that needs to be worked on.

I was just curious if you have to remove the 3rd from the housing in order to change a pinion seal out. All of my other leaks have stopped (knock on wood), and would reeallly like to reduce the risk of opening them up again by pulling the 3rd out.

 

[Arivalsend]

Pinion seal replacement

I have done a variety of pinion seal work on different older trucks. They are pretty straightforward replacements which really only involves the removal of the driveshaft from the differential, and unbolting the the coupling off of the 3rd (exposing the seal). From here you just need to pull out the old seal, clean the interior, and refit the new seal with a large socket and hammer. You can then push back in the coupling and torque the bolt which secures it back to the factory specs. Just make sure to mark the shaft/coupling before you unbolt the d-shaft. Otherwise you are likely to create a unharmonic shimmy in your drivetrain, due to the driveshaft being reattached in a different position. Your replacement pinion seal could have gotten nicked putting it in and thus is leaking once again. Either that or it was seated in with some grit and the oil is seaping out around it. Good luck on it.

 

[BigAl]

I've never worked on a toy rearend, but you might want to check to see if your drive shaft is bent or out of balance. I had a bent front drive shaft take out a front pinion seal on mine already. Good luck

 

[cruiseroutfit]

Check your pinion flange for wear at the sealing surface... if worn, replace (under $40). Be careful when re-installing the flange that you don't over-torque as you can easily crush the crush-sleeve if equipped.

 

[CYi5]

Thanks for the replies. The shop that did the work has a one year warranty against leaks, so i'll probably pick up a seal tomorrow and have it done Monday.

I'll mention your suggestion cruiser, i'd hope they would know these things already...but ya never know!

 

[taco chaser]

You do not just simply pull it off and replace it unless you have replaced the crush collar with a solid spacer and shim kit. If you still have crush collar inside than you can do it but you have do be very carefull by indexing the nut to the flange and you will need an inch pound pinion torque wrench, not your normal torque wrench to check the preload as you retighten to keep from over tightening the preload past your indexed marks or 17 inch pounds. With the solid spacer, there is nothing to crush to far or not far enough, all preload is set with shims so it makes pinion seal replacement easy, with this you can simply pull the pinion flange, replace and retighten. If you keep blowing through seals it could be your driveline support bearing is shot making your driveline spin way out of balance and actually hop. Did they change ratios when doing the work? IF your flange seal surface is the cause of your seal damage take green brillo pad and scrub the surface in one direction smooth again, it works everytime unless the surface is way far gone.

 

[Grim Reaper]

Thanks for the replies. The shop that did the work has a one year warranty against leaks, so i'll probably pick up a seal tomorrow and have it done Monday.

I'll mention your suggestion cruiser, i'd hope they would know these things already...but ya never know!

But you also don't want to under torque either. I an ideal situation you would have a inch pound torque wrench and tighten till you get to the "used bearing" rotational preload (about 12inlb). Hard to do with an assembled axle since you are spinning the axles shafts. Try to get it back to the same point. With Toy's staked nuts thats usually not a problem just be careful when you pry the stake out.

If you have to replace the nut then I would recommend pulling wheels and brake drums and tighten using the preload settings. Failure to do so may allow the pinion to deflect and that my cause a bearing, Pinion seal, or R&P failure.

Have you checked the run-out on the pinion? Could be bent from hitting a rock and that would be something that would lead to seal failures.

 

[CYi5]

I'm not too familiar with some of the tests, but i'll certainly make a list of things and hand it to the tech. I'm sure they're getting tired of seeing my truck and would like a few more suggests .

 

[p1michaud]

Pinion seal leaking

Has your rig been re-geared? If not, I'll assume that you have a crush type sleever. If so, you need to be very carefull not to over or under torque the pinion nut as previously mentionned. The FSM tells you to use the back lash in the gear set to check the torque value (in-lbs) but I can tell you that this is not a practical test. You don't have enough room to get a decent torque reading with just the back lash. The best way would be to remove both rear axles, replace the pinion seal, check the pinion flange for wear/damage, set the pinion pre-load up again to 8 - 10 in-lbs (I think) per the FSM. Re-install the axles, bleed brakes and you are off. I'm most cases the guys at the garage won't bother with all this work. Stay and watch if you can.
Good luck.
P

 

[CYi5]

Yea its regeared with OEM Toyota 4.56's in it.

Well little update here. Truck has been in the shop since yesterday. They have replaced the seal once and it is doing the same thing. They thought it might be the center bearing as the rubber seemed somewhat loose, so they went ahead and replaced it. I didn't mind too much as the truck has 155k on the clock. They picked up another factory Toyota seal from another dealership and told me that it is really difficult to place on the pinion*? As in, really have to elbow it over the shaft.

It happened with the seal I brought them which also matches the VIN on my truck, and they are pretty sure it will just repeat with the one I gave them.

Sooo, as it stands now, they are keeping the truck for a couple more days to pull the third and put it on a lathe to ensure that it is not wobbling and actually spinning true.

It's not much fun being without my daily driver, but I appreciate that they are taking the time to honor their warranty and not just give me back a truck that will leak next day.