88 4runner rear differential leak
05-14-2017, 08:47 PM
#1
88 4runner rear differential leak
I have a 88 4runner and now the rear differential is leaking. I narrowed it down to the drive shaft entering the differential. I know i have to change the seal, but I noticed it made a suction noise when I open the fluid refill bolt. I checked the breather on top of the axle and it was totally clean, no blockage at all. Before I change the seal I want to figure out what's making the differential not ventilate properly or else I am gonna be changing the seal again and again. Please help, any advice is good.
Last edited by Toycoma33s; 05-15-2017 at 08:53 PM.
05-15-2017, 02:11 AM
#2
Registered User
iTrader: (8)
Join Date: May 2011
Location: Southeast Virginia
Posts: 1,510
Likes: 0
Received 346 Likes
on
215 Posts
If I recall correctly, inside the axle housing under the breather, there is a little baffle of some sort to keep oil spray from just misting out of the breather all the time. You might want to blow some low pressure compressed air into the top of the axle housing with the breather removed and see if anything clears up. Also, when you replace the pinion seal, technically you should replace the crush sleeve too since they aren't reusable. But some people have gotten away with just counting threads and putting the nut back to the factory stake mark. I did this and it was fine for a couple years before I swapped the differential out for an E-locker. When I say it was fine, I mean it didn't leak, blow up, or make noise. It didn't really have any bearing preload though and there was a bit of play. Not ideal. Just wanted to inform you so you can make a good decision for yourself.
05-15-2017, 05:43 AM
#3
Registered User
Many 3rd members with high mileage are found with somewhat loose pinion flanges, so simply re-tightening the nut back to where you found it leaves the flange a bit wobbley again.
You can re-torque the pinion nut to 100 foot pounds, or more without additional crushing of the crush sleeve.
I have re-tightened several to 130-140 foot pounds without substantial harmful increase of pinion preload and have run them tens of thousands of miles without trouble.
Of course, if serious pinion bearing wear, or damage has caused the looseless, there's gonna be trouble ahead, no matter how much, or little you tighten it back up.
You can re-torque the pinion nut to 100 foot pounds, or more without additional crushing of the crush sleeve.
I have re-tightened several to 130-140 foot pounds without substantial harmful increase of pinion preload and have run them tens of thousands of miles without trouble.
Of course, if serious pinion bearing wear, or damage has caused the looseless, there's gonna be trouble ahead, no matter how much, or little you tighten it back up.
Last edited by millball; 05-15-2017 at 05:47 AM.
05-15-2017, 08:58 PM
#4
Thank guys for the info. After i got home today i loosened up the breather and listened for air. There was none and the axle wasn't leaking. Nevertheless I will still replace the seal and hopefully the axle will still breathe. I'll take all of your advice in mind and do it right.
