Transfer and pinion seals?

[Toybox]

Would anybody happen to have the dimensions for the rear output seal (the oil seal that fits around the rear output flange) on the transfer? And the pinion seal on the front diff?

I'd like to get em on the way home and forgot to take em out last night... bugga...

[Sifu-Lux]

Hi Jonathan,

Rear output seal is 58 OD, 38 ID, 11mm Thick. This is the straight type oil seal (Bearing Man etc), which I am using.

Toyota genuine seal in a uni-directional helix oil seal. The same dimensions, but with directional helix "oil pumping" ridges. The genuine Toyota seals on the front and rear flanges of the transfer case are not interchangeable as they are uni-directional. See here: http://www.tobar.com/pdf/helix_design.pdf

If you fit straight lip type oil seals, you can fit the same front and back.

As far as I know, the diff pinion seal in the same, but I'm not sure.

[Toybox]

Thanks Andrew, you're dead right. I actually just finished getting the transfer one out. 58/38/11/3mm...

I'm struggling to lift that pesky locking tab on the front pinion so that seal will have to wait till I'm feeling more patient (and have bought another small screwdriver)

[Sifu-Lux]

Post some pics of the front pinion seal replacement for when I have to do this one day :) :)

[Sifu-Lux]

So the day finally came, and I had to replace a weeping front diff oil pinion seal.
You don't have to remove the front diff to do the oil seal replacement, but I had it out anyway
to fix my leaking ARB air locker.

In order to take the flange off, I made a tool / flange holding plate, otherwise removing the nut is rather difficult. Here is a quick drawing for reference. It
holds the flange stationary, and clamps in your vice.

[Sifu-Lux]

Now for the really important critical part !

BEFORE you remove the pinion nut, know the following:
The pinion shaft and and bearings are assembled with a crush sleeve, which is compressed when the
diff is assembled to get the correct gear teeth mesh between the ring and pinion gears, and provide the correct
pre-load on the pinion bearings.

Before you remove the nut, check exactly where it sits on the pinion shaft. Count the exposed threads.
Mark the relative position of the nut (you can use the stake mark) to the pinion shaft (key way)
When you remove it, count the number of turns until it comes off. You need to put it back and tighten it
up to the exact same place (+ 1/8 of a turn) to ensure you don't under tighten it, or over tighten it and crush
the crush sleeve further, which will affect the gear teeth mesh on the ring and pinion, and increase the
pinion bearings pre-load. Over time this will lead to ring and pinion failure, and failed bearings.

With the nut now removed (30mm socket if I recall), you need to remove the flange. For this I used a home made puller.

Here is the oil seal with the flange removed

[Sifu-Lux]

I phone Toyota for the seal price, and as usual was shocked... R 146.00 ea.
So I did my usual web research and got one from Bearing Man (BMG) which is exactly the same for R12.50ea
I did however buy a new pinion nut from Toyota at around R25.00ea.

The pinion oil seal info is as follows: (front and rear diffs on import axles are the same)

Pinion oil seal:
Dimensions : 38*74*11/18 HTBR (get from Bearing Man BMG)
Toyota part number 90311-38035

Pinion nut:
Toyota part number 90179-20001

[Sifu-Lux]

Here is a pic of the pinion shaft and bearing with the oil seal removed

Bearing flange washer lying below in pic (removed to show bearing)

Now the new oil seal is tapped into place (I used a 54mm geyser element socket as a driver to get it seated evenly)
Lubricate the oil seal face with some MS grease.
Clean and inspect the pinion flange for any wear on the oil seal face (sometime has a groove, but more so on the rear diff which has more use)
I gave mine a light sand with 1200 grit water paper to polish it up. Put some MS grease on the oil seal face of the flange.

Press the flange on by hand and tap it into place with a nylon hammer, you can apply a small amount of silicon gasket sealer to the splines if you want.
Put the washer back in place and fit the new nut

Carefully tighten it back to the original position (you can feel the resistance when it starts to load up) Don't over tighten it!

Turn the flange by hand to feel the approximate load feels the same as before. (you could use a fish scale if you want to be 100% sure)

The final product done (some painting to make it look nice )

[Mud Dog]