School me on Front Pinon Seals / Bearings (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jun 24, 2018
Threads
17
Messages
146
Location
East Bay Area, CA
Hey there 'Mud,

Just finished the 'rite of passage' front end rebuild on my Vortec '60. (Chromo-Inners, Longfields, TRE's, Steering box, Hi Steer, Brakes/Rotors, etc./etc./etc. and all the bearings and seals)

During this work, I'd had a pesky 1-2 drop a day FRONT pinion seal leak from my axle, so figured I'd put in a new Eco-Seal Marlin Crawler seal, and re-fill with fluid per the FSM. Hopefully Bob's yer' Uncle and all's fixed.

Notably; Pinion felt good, lateral/vertical movement was less than 1mm (not measured, but tested by hand) :bang:


But, now, it seems it's leaking more. And, man... EVERYTHING else went in so well.

SO; I've been searching but unable to find a conclusive answer other than what I can intuit about replacing the inner bearing that the pinion gear/shaft rides on. My questions are as follows:

1) Does the entire diff need to come out to pull the bearings?

2) Could the torque of the flanged nut on the companion flange be the cause? (Torques were between 128ft/lb and like 300ft/lbs)


3) Is there any other issue I could have that one of you is familiar with that could cause this new leak now?


THREADS that helped me get this far:

RE: FJ80 with same issue

Any 411 would be appreciated!
🔥Thanks
 
You replaced the front pinion seal because it was leaking a little and now it's leaking more? If it was me, I’d suspect the last thing I touched. When I had a leaky rear pinion, I chickened out, pulled the diff and took it to a shop. Those diffs usually have a crush sleeve which can be a little tricky to re-torque. You mark the position of the stake nut before you remove it, and then tighten back to the same spot.
 
Last edited:
Those diffs usually have a crush sleeve which can be a little tricky to re-torque. You mark the position of the stake nut before you remove it, and then tighten back to the same spot.


Thanks for the reply. This sounds like a feasible solution. There's a local gear shop to me that I'm going to drop by later in the day. However, I was simply hoping that it was that type of thing... a mis-torqued nut, a poorly installed seal... etc.

We'll find out later.

I have a 700mi round trip (no off road/4x4) this weekend upcoming... I just want a seal of approval *hehe* about driving that far and having it not be critical to fix until next month if it requires pulling the front diff.
 
Witness.

Thanks for the knowledge. I'm thinking @FJ60Seth is right with regards to blaming the Crush Washer. I'll let you know what I found out later.
 
Whenever you have a pinion seal leak....

Check your front axle vent. The spring-loaded rubber 'cap' on the factory setup can stick and cause pressure in the axle. It's takes very little pressure to cause a leak.

I suggest you remove the factory hose and install a section of fuel line up the firewall to a high location and stuff a fuel filter in the end. A free-breathing axle is less likely to leak than one that sees random pressure or vacuum.
 
Whenever you have a pinion seal leak....

Check your front axle vent. The spring-loaded rubber 'cap' on the factory setup can stick and cause pressure in the axle. It's takes very little pressure to cause a leak.

I suggest you remove the factory hose and install a section of fuel line up the firewall to a high location and stuff a fuel filter in the end. A free-breathing axle is less likely to leak than one that sees random pressure or vacuum.

Excellent suggestion. I have a extended breather as well. I'll double check this tonight. Totally forgot to think of this... but when I had my rear ARB locker leaking 80w-90 from the compressor in the engine bay, I determined that my rear dif breather was plugged. Problem solved when I cleaned the breather.

Thanks
 
Hey there 'Mud,

Just finished the 'rite of passage' front end rebuild on my Vortec '60. (Chromo-Inners, Longfields, TRE's, Steering box, Hi Steer, Brakes/Rotors, etc./etc./etc. and all the bearings and seals)

During this work, I'd had a pesky 1-2 drop a day FRONT pinion seal leak from my axle, so figured I'd put in a new Eco-Seal Marlin Crawler seal, and re-fill with fluid per the FSM. Hopefully Bob's yer' Uncle and all's fixed.

Notably; Pinion felt good, lateral/vertical movement was less than 1mm (not measured, but tested by hand) :bang:


But, now, it seems it's leaking more. And, man... EVERYTHING else went in so well.

SO; I've been searching but unable to find a conclusive answer other than what I can intuit about replacing the inner bearing that the pinion gear/shaft rides on. My questions are as follows:

1) Does the entire diff need to come out to pull the bearings?

2) Could the torque of the flanged nut on the companion flange be the cause? (Torques were between 128ft/lb and like 300ft/lbs)


3) Is there any other issue I could have that one of you is familiar with that could cause this new leak now?

THREADS that helped me get this far:

RE: FJ80 with same issue

Any 411 would be appreciated!
🔥Thanks
The pinion nut sets preload on the pinion bearings by crushing the crush sleeve. This is not a specific torque. Needs to be properly set up while off the truck or at least with the axles pulled. You have probably over tightened the nut and this will destroy the pinion bearings. If you tightened the nut past the original setting you have crushed the crush sleeve too far and have too much preload on the bearings
 
The pinion nut sets preload on the pinion bearings by crushing the crush sleeve. This is not a specific torque. Needs to be properly set up while off the truck or at least with the axles pulled. You have probably over tightened the nut and this will destroy the pinion bearings. If you tightened the nut past the original setting you have crushed the crush sleeve too far and have too much preload on the bearings

This is a good theory. I probably did ham fist it with the Impact. >.<
 

Users who are viewing this thread

Back
Top Bottom