Front Diff - Rear Oil Seal has Failed... Excuse to go ARB or Easy Seal Replacement? (1 Viewer)

[suprarx7nut]

The rear oil seal of my Front Diff has failed and I'm leaking diff oil at the companion flange. To replace the seal, looks like $50-100 in various one time use parts and a good amount of work - nearly what's required to install an ARB, perhaps?

Has anyone replaced the front diff rear oil seal? How big of a pain is that job?

I'm planning on a locking front diff, but was thinking that'd be a 2020 era mod, not 2018. Doing now would be some good peace of mind, but would delay other projects that I'd rather tackle. I'd only jump to the ARB if the labor for each is similar.

Anyone else find themselves in this position?

Rig is a 99LC with 33's, Slee Sliders and soon a BIO Rear Bumper. 256k miles.

 

[Skidoo]

Yes, mine was leaking and just reinstalled diff. If you have a pinion bearing crush sleeve spacer (in other words factory) you can not replace seal without taking diff apart to replace spacer. Most aftermarket installs now use a solid spacer in which case, seal can be replaced without diff teardown. I already had ARB in diff and was getting metal in diff oil change, so pulled diff to see what was going on. Since I was in there changed from factory 4:30 to Nitro 4:88. Also in many cases it is a good idea to replace the yoke flange as seal may have worn a groove in it (as was the case with mine).

Here is a place to look for more info on diffs or to have work done.
Gear Install Harrop

BTW, love my titanium key.

 

[nissanh]

If you are going to get the diff off the truck and all that work, it will cost a lot.

If you can count the number of turns to remove the nut off the pinion perfectly, I think you can install a new diff pinion oil seal (and with a new flange as most flanges at 200K miles will have a minor grove), I think this is doable job. I did one to a taco and so far so good. Make sure to get an OEM oil seal.

 

[Jeepster09]

Yes, mine was leaking and just reinstalled diff. If you have a pinion bearing crush sleeve spacer (in other words factory) you can not replace seal without taking diff apart to replace spacer. Most aftermarket installs now use a solid spacer in which case, seal can be replaced without diff teardown. I already had ARB in diff and was getting metal in diff oil change, so pulled diff to see what was going on. Since I was in there changed from factory 4:30 to Nitro 4:88. Also in many cases it is a good idea to replace the yoke flange as seal may have worn a groove in it (as was the case with mine).

Here is a place to look for more info on diffs or to have work done.
Gear Install Harrop

BTW, love my titanium key.

That is incorrect, when replacing pinion seal check the pre-load with dial type torque wrench before disassembling and record the reading. Next install the seal and torque nut to factory spec in increments while rechecking pre-load with dial torque wrench. NOT A BIG DEAL techs replace pinion seals all the time. As long as you do not exceed the original pre-load you should be ok. Exceeding the pre-load crushes the crush collar further which can cause problem.

 

[Skidoo]

If you are going to get the diff off the truck and all that work, it will cost a lot.

If you can count the number of turns to remove the nut off the pinion perfectly, I think you can install a new diff pinion oil seal (and with a new flange as most flanges at 200K miles will have a minor grove), I think this is doable job. I did one to a taco and so far so good. Make sure to get an OEM oil seal.

Be aware there is risk to replacing seal without new spacer, as it sets preload of pinion bearings. Too much or too little and bearing life gets real short. Also when you replace the yoke, you are counting that it is made to the same exact size as old and not at the other end of acceptable range of tolerance.
So you are counting on an element of luck, just have ask yourself if you feel lucky.

 

[Jeepster09]

I am not sure on Land Cruiser, but flat rate on most pinion seal jobs is only 1 to 1 1/2 hours.
As a former master tech I have done many pinion seals with out issue.

 

[Spike555]

With my Land Rover I was in a similar situation with the transfer case, the front seal was leaking, which meant removing the t-case, seal was only like $6 but the labor involved was not something I wanted to do.
So I tried this, worked great. Stopped the leak and I forgot about it for 5? yrs until I sold the truck and read your thread.

 

[Skidoo]

That is incorrect, when replacing pinion seal check the pre-load with dial type torque wrench before disassembling and record the reading. Next install the seal and torque nut to factory spec in increments while rechecking pre-load with dial torque wrench. NOT A BIG DEAL techs replace pinion seals all the time. As long as you do not exceed the original pre-load you should be ok. Exceeding the pre-load crushes the crush collar further which can cause problem.

It seems like it would be difficult to get a consistent preload readings as you have brake drag, CV joints etc. Maybe you mean after you have pulled diff.

 

[Jeepster09]

I never had a problem. Just check it several times [with dial torque wrench, not click type torque wrench] and re-set it at same reading. Again torquing nut to factory spec. Remember when torquing, check pre-load several times to get consistent reading. Remember that IT SHOULD OF BEEN TORQUED to factory spec first time, so torqing to same reading should not be an issue. You see problems when techs use impact and just run the nut down without checking torque. It then gets over torqued and crush collar gets over crushed changing pre-load.

 

[Skidoo]

Not that it precludes on vehicle replacement, the FSM does not show on vehicle rear seal replacement for front diff, while it does show on vehicle replacement of both diff side seals that CV axles plug into, and it is a lot more work to get to those.
Before starting my diff teardown, I asked Nitro Gear tech folks if I could just replace the rear seal and yoke and their answer was no, unless I had a solid spacer.
So that is what I have learned, but since this is the first diff I have regeared, can't say I am a wealth of experience.

 

[suprarx7nut]

Hmmm... good discussion. In the figure attached, which part is this crush sleeve/washer?

View attachment 1578157 With my Land Rover I was in a similar situation with the transfer case, the front seal was leaking, which meant removing the t-case, seal was only like $6 but the labor involved was not something I wanted to do.
So I tried this, worked great. Stopped the leak and I forgot about it for 5? yrs until I sold the truck and read your thread.

I'm normally not a fan of these stop leak measures... but in a front diff... maybe worth a shot.

 

[Travis 76]

Most likely the 41231F.
I haven't been into one of these, but that looks like it.

 

[Jeepster09]

Most techs don't bother doing pre-load check.....just replace the seal and torque pinion nut to spec. If you go by spec and don't over torque it you normally are good to go. Over torquing is what changes the crush thickness.

 

[nissanh]

I seriously wouldn't worry about getting the pinion seal replaced. Have done a few on toyota's and never had an issue. I count the turns to remove it and then tight it exactly the same.
Will not do it to any other brand of trucks as I live with toyota's for my life.
Something to enjoy...

 

[Skidoo]

It is the 41231F.

 

[Spike555]

Hmmm... good discussion. In the figure attached, which part is this crush sleeve/washer?



I'm normally not a fan of these stop leak measures... but in a front diff... maybe worth a shot.

View attachment 1578340

He's going to open the front diff eventually but he wants to get other things done first, I'm not a fan of stop leaks either but that one works, I can confirm that.
That might by him time to do the things he wants to first and then he can tackle the front diff at his leisure.
I have no idea how bad it is leaking, he didnt say.

 

[suprarx7nut]

Thread update:

I tried the Stop Leak stuff and if anything, it increased the leak rate. No luck there.

I called around to get some estimates from shops and a local differential shop said they'd never had issues replacing it in car. They were a little confused why I was talking about removing the diff and bringing it in. Book time on the job "in car" was a couple hours, as @Jeepster09 mentioned and the shop thought that was even a little much.

I'm going to try this on my own. I've got a lift in my heated garage full of tools so I've little to no excuse not to give it a shot. Once I get a steering wheel back on my other car, I'll pull it off the lift and get the cruiser up in the air to address this. It seems worst case scenario, I screw up the preload and ruin a bearing forcing me to actually have it disassembled. Between my careful hands, a few torque wrenches and some rotation measurements I think the risk is pretty low.

 

[lt1fire]

you can replace the seal yourself.... the thing you should be doing is tricking yourself into thinking you cant and just have a shop put a locker in there.

 

[nissanh]

Just count the number of turns you are turning the nut to remove the pinion flange and then turn the same number of turns when you are putting it back on.

 

[reznunt]

Go all out and get the locker/regear so we can live vicariously