OK, it looks like the pinion bearing is starting to go in my rear differential. Couple of questions:

1. Does the entire differential need to be removed?

2. Can the bearing be changed in place once the driveshaft is unbolted?

3. I'll obviously need to replace the seal along with the bearing. Anything else? Do I need shims or a crush sleeve?

If I wanna do it this weekend, gotta order parts pretty soon, so any help would be appreciated.

How many bananas to do this job? If I gotta remove the diff, may just wait a bit and put in somer 4.88s.

1. Does the entire differential need to be removed?
No, but the easy way is to remove the carrier unless you only want to change the outer pinion bearing and you are Houdini and can get the outer race out. I've heard that you can get it out with a slide hammer with a claw attachment. If you mark the carrier side bearing adjuster nuts, you can easily get the carrier back in in exactly the same way it was. It is easier to get the pinion preload correct with the carrier out and the 3rd member on your bench.


2. Can the bearing be changed in place once the driveshaft is unbolted?
It is possible if you can get the old outer race out. Getting the pinion preload correct will be a little more difficult, but be sure to measure the total preload before you start and make sure that the total preload is within specs after you change bearings.


3. I'll obviously need to replace the seal along with the bearing. Anything else? Do I need shims or a crush sleeve?

FJ40s use shims (and most 60s too). If the shim and preload adjusting washer has "spun" you will probably need new ones. Get the complete set of preload washers (something like 10 or 12 at $2 each) and once you find the correct one take the other ones back. You don't want to have to get a larger one on Saturday when the dealer is closed.

If you replace the inner pinion, you should at least check the pinion depth with gear pattern compound. I have gotten lucky (2 out of 2) in getting the correct pinion depth just reusing the original depth washer.

Thanks for the reply. Having nexer taken apart a 3rd member, wasn't aware there were two pinion bearings. Sounds like I oughta replace both, which will require pulling the 3rd.

That will push it to next weekend then.

One more question: I have a Haynes, not the official Toyota Manual. Are the instructions in the Haynes Manual correct and accurate?

Probably 9 times out of 10, only the outer bearing is shot, but I prefer to change them all as the little flakes of metal get all over. You can usually get the whole installation kit (all 4 bearings) for the price of the two separate pinion bearings. Preload shims do not come in most kits and you will need to get these from Toyota or SOR etc.

The inner bearing is a little harder to pull off of the pinion. I used a large, 2 jaw gear puller, but a plate type bearing "splitter" will work too. You will need a plate type puller if you need to reuse the bearing when resetting the pinion depth as it does not destroy the bearing. Putting the new inner bearing on was easy: Don't forget to put the depth shim on first, then freeze the pinion and heat the new bearing to about 250 F. The new bearing slides on slick as snot on a door knob. Check the pinion depth before anything else. Randy's ring and pinion web site has a tech article on it, but it is not too detailed.

I don't know about the Haynes manual, but I imagine it would be fine.

I personaly would not recomend doing
this job the first time with out some
help from a qualified person
unless this is a trail rig only.

I've done a 3rd member before, but it was a long time ago on a 1974 Pinto. That was a weird one. The way you figured your bearing preload on the side gears was by measuring the case spread. Very strange.

So who wants to help? I'll supply the beer and wheelin's only 2 blocks away.....

Just doing the pinion bearings is a 2 bannana job, since you probably won't have to reset the pinion depth and you can get the backlash and carrier preload back to where they were just by marking the adjuster nut positions and sides.

A new R&P or a new carrier is a 3 bannana job, since setting the pinion depth by trial and error can be a PITA.

I say go for it if you are reasonably competent and you pay attention to what you are doing. If you were down here where it is warm, I would do it for a case of Sierra Nevada pale ale.

well if you have done one before
I will give you some advise.

usualy you can get away whith the
same size shims.

but i recomend buying a extra bearing
and useing a break hone to enlarge
the inside diameter so that it
is a slip fit use this bearing to
test fit every thing before presssing
the new bearing on.

the fj third is a real easy third
to work on much easyer than a dana axel.

as long as you have it out and apart
you might think about changeing the
gears to a fine spline pinion.
they are a lot stronger..

Thanx Landcrusher

Good tip on the extra bearing. Assume I could use my old one. Or does it need to be "fresh" to get proper measurement?

Was thinking about going 4.55 or 4.88 cause I'm eying 35s.

Would my old 4.11s fit in an IFS Fourskiner? Kid's got an 89 that I think has 3.73s. If they swap, its time for a diff. party!