Rear pinion seal FJ60 1986

[Aircooled1]

I've got a leaking rear diff at pinion seal. Going to replace the seal. Should I get the kit with the crush piece, or just get the seal and reuse the nut, leaving the crush piece in place and retorque to original nut position based on markings i will make?

Second question on this topic... Should I replace the front pinion seal as well while I'm at it? or is this something that should only be done if it is leaking?

 

[brownbear]

It's not a good idea to replace the seal while installed in the vehicle as you cannot set up the proper pre-load on the bearing.

First thing I would check is to see if the pinion flange has any movement up and down, side to side etc. Your bearings could be worn out and putting in a new seal will only fail very quickly.

But others on here might have a different approach. I did the seal on my T-case to try and slow a leak, but I had some play and it didn't do anything.

My rear diff also leaks and I am going to replace all the bearings and re-set up.

 

[SteveH]

Before you replace any seals, properly vent the axles by removing the OEM vent cap on the axle and installing 3/8" fuel line, run high up under the chassis.

Some (not all) pinion seal leaks are due to pressure in the axle from these vents. On many of my Land Cruisers, the rubber disk on these seals was glued to the top of the vent with gummy old oil, and caused a permanent axle seal which allowed the pressure to build in the axle and the pinion seal to leak. Poor OEM design, in my opinion.

RE: replacement technique - I would replace the seal and torque the nut to its original position. I would also NOT do the front for the heck of it - many of those seals last nearly forever, due to lower use than the rear seal (part time 4WD).

 

[Aircooled1]

I will check the vent first . Thanks. The truck is getting the body off and i wont have a chance to run it for a while. however, if the vent is blocked I will replace the line and hopefully that will help the new seal last longer.

 

[brownbear]

I would also say a small seepage is not such a big deal as long as it can be topped up on oil changes and not go too low.

 

[ravenplague]

I just did this exact thing. I bought an OEM seal but wanted to buy a Marlin rear diff seal but they were out of stock. You will also benefit from buying a new stake nut. I marked the nut and measured the threads using a caliper. Removed the nut, struggled getting the old seal out and replaced both. Re tightened the new nut to the exact position and added a 1/8 of a turn. It was pretty easy