1991 FJ80 Front Axle seal WONT stop leaking! (1 Viewer)

Joined
Jan 22, 2015
Messages
5
Location
Portland Oregon
 
Hi Internet and IH8MUD family,

I've got a pretty solid 255k 1991 FJ80, tires, brush guard & winch etc entry level trail ready ..... but a few years back I did crack the spider gear in my front diff and ended up having a shop replace the whole front end. Everything was great.

Since then, I had my front right axle seal start leaking and despite my best efforts I can't get it to stop. By the time I got around to installing maybe my 3rd axle seal, assuming i'd been simply doing something wrong, I noticed the axle itself where it spun on the seal had the obvious signs of wear. Assuming at that point the axle shaft had been worn enough that it couldn't seal properly and clearly that was my issue, I replaced it. I bought a front right axle shaft (used) with less visual wear and best I could tell (visually and with straight edge) to be in highly serviceable shape.

That didn't fix it. I replaced the seal when I put in the axle, but she still leaks. I just hate the mess and I'm in my head about running low on gear oil and ruining my diff again..

What else can I try?
-I've read a little about using a sleeve to make a new perfect surface, but is that even my issue!?
-Can I just put a bunch of elmers glue in it (kidding)?
-Could my oversized tires be a root cause?
-Am I just stupid and simply installing the seal wrong somehow?

Appreciate any feedback or suggestions on what to try next...

-Eric in Portland
IMG_0097.JPG

IMG_0014.JPG
 
Joined
May 26, 2005
Messages
7,820
Location
Phoenix
 
 
 
What seal are you using? Just having the right ID and OD is not enough. Toyota uses a seal with a bellows design that allows the shaft to move a bit, standard parts store seals do not have this feature.
 

jfz80

Spicy
Joined
Jun 5, 2005
Messages
12,100
Location
Madison NC
 
 
 
Define “whole front end”
Parts and pieces or new donor axle and housing assembly?
Bent axle housing a possibility?

I’d reinstall an OEM Toyota seal and overdrive it with the wits-end offset seal driver if it were mine.

there is a speedi-sleeve avail as well.Don’t have part number off hand but it’s catalogued here in the thread archives. Maybe even faq?
 
Last edited:

Cannon88

In the duck blind...
Joined
Dec 7, 2009
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2,040
Location
Ft. Worth, TX
 
 
Can you see where it is leaking from at the seal?

On my old 80 there was a tiny knick in the metal where the seal would seat. It was tiny, but small enough to create a dimple in the seal and fluid would run out. Once I found it I filed it smooth and never had another leak once the seal could seat properly. No clue how it got there, maybe a PO did it installing one incorrectly, or removing an old one with a screw driver or something. No clue. Lol
 
Joined
Dec 17, 2007
Messages
4,417
Location
Sydney, Australia
 
 
good suggestions above.

I'd also replace with an OEM seal, punch it in a few millimetres further.
check the surface the outer diameter of the seal fits against too. (I've also experienced a small gouge in the diff housing causing a leak)

if you've done all that, time too check the diff housing isn't bent.
also check that shims on the trunion bearing caps are still in place. if the knuckle was rebuilt, it's possible shims may not have gone back correctly
 
Joined
Feb 11, 2011
Messages
578
Location
Wisconsin
 
originally the seal is pressed all the way in so you can't overdrive it
what i did i took carbide teeth hole saw and cut the seal hole deeper for 1/16 " and no problems pushed new seal all the way in and no problems
 
Joined
Jan 22, 2015
Messages
5
Location
Portland Oregon
 
Hello, Happy New year first off - thanks for all the feedback.

@ Spike - it's a seal from a part store "that fits my FJ" can't say much specifically beyond that.

@ JFZ80 - they replaced the entire 3rd member, axles and everything. sourced from a landcruiser place back east, wish I had more details. So maybe it's bent, but I put some faith in having been sold decent parts (famous last words I know)

@Cannon88 - I don't feel or see anything like a burr. The FIRST seal was in bad shape when it came out, since then all the seals I've pulled out have only been damaged by me removing them, none were visibly leaking from a tear or anything best I could tell.

@ heckraiser - i'm ready to re-try overdriving a seal. I had before, but it was before axle #2 so maybe I CAN find a sweet spot where it sits right and doesn't leak.

@mudgudgeon - trunion bearings would be a new troubleshooting frontier for me to consider. hmm..

Thanks again to everyone - if there are any other ideas i'm all ears.

In the interim, i'm going to consider trying to overdrive one more time. Also what about a heavier duty bearing with a flange, I see some offroad one, but since they're flanged wouldn't that prevent me from over driving them??
 
Joined
May 26, 2005
Messages
7,820
Location
Phoenix
 
 
 
Hello, Happy New year first off - thanks for all the feedback.

@ Spike - it's a seal from a part store "that fits my FJ" can't say much specifically beyond that.

@ JFZ80 - they replaced the entire 3rd member, axles and everything. sourced from a landcruiser place back east, wish I had more details. So maybe it's bent, but I put some faith in having been sold decent parts (famous last words I know)

@Cannon88 - I don't feel or see anything like a burr. The FIRST seal was in bad shape when it came out, since then all the seals I've pulled out have only been damaged by me removing them, none were visibly leaking from a tear or anything best I could tell.

@ heckraiser - i'm ready to re-try overdriving a seal. I had before, but it was before axle #2 so maybe I CAN find a sweet spot where it sits right and doesn't leak.

@mudgudgeon - trunion bearings would be a new troubleshooting frontier for me to consider. hmm..

Thanks again to everyone - if there are any other ideas i'm all ears.

In the interim, i'm going to consider trying to overdrive one more time. Also what about a heavier duty bearing with a flange, I see some offroad one, but since they're flanged wouldn't that prevent me from over driving them??
Get a factory seal. They are not standard. Make sure the vent isn't blocked.
 
Joined
Oct 15, 2019
Messages
165
Location
Ocracoke island North Carolina
check your axle breathers. Somebody on here suggested that to me. on my 1991 the breathers were all gummed up causing the rear pinion seal to fail and the front axle seals to fail. I replaced the seals and the breathers and no issues since. breathers are a cheep and easy fix and really should be a routine tune up thing to check.
 
Joined
Jan 22, 2015
Messages
5
Location
Portland Oregon
 
Hello again and thanks again for all the previous feedback.

I've been keeping it topped off and playing all summer. finally digging in, here is how much it leaked in just two days before I started
the leak.JPG


Huge shout out to Jonesy's on YouTube, great step by step two part video showing the whole process for reference.

A followup write up; lessons, observations, successes and next steps.
-the kit I bought off Amazon had too many parts, probably could have sourced just barely cheaper w/o waste. nice to get a turn key kit tho.
-front was pretty easy to disassemble, sure i've done most of it a few times but the burfield didn't challenge me much
-I saw and felt problems: orange seal was my leaking passenger side, other was my "barely leaking" driver side.
-clearly the driver side had failed, this is one I had never replaced.
-the leaking passenger looked fine I guess, but I actually was able to pull it with my hand.
-this is the seal I replaced several times with this same napa replacement. I think this has been a poor quality part or fit from the beginning and a continued source of my frustration on why it was leaking when everythign looked fine. took me doing them side by side to really notice the difference.

bad seal.JPEG
pass side.JPEG

Here are both types of seal new next to each other, both fit. the metal outside one was clearly better in quality and fit.

seals.JPEG


Another thing I noticed was how different each hubs overall oil and fluids were holding up.

the leaking, rubber sealed problematic side, had gear oil spilling out of the wheel hub, and the bearings and burfield greases's were just watered down and mixed and the whole thing looked .... rinsed ..

the not so leaking, driver side, with the failed seal, seemed in need of change. all the greases were very dirty and grimey

this took me 3 days basically., I bent an inner seal day one and it took me ordering it from a second place (thank god I live so close to discount imports) so it took a few days.

I also learned a hard lesson about removing the ball joint with a hammer :) and was lucky enough to be able to afford the $30 replacement since the thread was "not so gently" removed.

all and all the rebuilt was almost two weeks ago, towed the boat, driven the truck a medium amount and i'm looking good!!

project.JPEG
 

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