NickS022

Getting ready to do the pinon seal on my 91 3vz 4runner and I know there is a crush sleeve in the diff and if I get my new seal to tight ill ruin my rear end. My question is how tight is to tight for my new pinon seal don't want to ruin my rear end? plz help this in experienced mechanic

coryc85

Nick - it's not the seal you are tightening, it is the pinion nut that holds the differential flange onto the end of the pinion. The general rule would be to note how much thread is sticking out past the nut right now (before loosening the nut) and where the stake in the nut lines up with the groove in the pinion. So let's say you have 5 threads sticking out past the nut, you would simply tighten it back into position so that 5 threads are showing and the stake dimple lines up with the groove in the pinion. It probably wouldn't hurt to go a little past that in terms of tightening too since your bearings have worn in over the years and could use a little more preload. Read www.gearinstalls.com for loads of information. I think 4Crawler's site also has some info on pinion seal replacement.

Good luck.

gregory_wilcox

You should be fine as long as you get the pinion nut onto the same position it was before. Like coryc85 said, you could probably even go a little tighter. Looser would be a problem. Note that I believe on the back diff you drive the seal in 1 mm. There is probably a lip that will stop it from going in further as long as you drive it in as evenly as you can. A pipe or socket that fits around the circumference of the seal will make it easier. You don't want to drive it in with something too small otherwise you risk denting and damaging the seal.

BTW I made some edits above w/r/t preload. I misunderstood it. The FSM is referring to backlash, which is a different measurement than what I was doing (see my other post here). Since I have the pinion nut onto where it was, I feel confident that it will be fine (phew).

jsabowabo

I just did the rear pinion on my 89 4Runner. I recommend having a spare seal on hand in case you ruin one ( I did and had to wait for a spare). Make sure you have a 54mm axle socket to drive it in. I tried doing it without which resulted in the ruined seal as I couldn't drive it on straight. As for the torque on the pinion nut, the FSM calls for 90 ft lbs. My pinion nut was loose, so I tightened to 90lbs. The other way to do it is just count the turns out and then just tighten it back up the same number of turns. You can overdrive the seal as well. I put mine flush with the diff housing and have no leaks or issues. I don't think it's that sensitive.

hidesert

Be sure to pack the garter spring on the back of the seal with heavy grease so it doesn't pop off when you hammer it in (guess how I know).