T-A-Z-M-A-N

I will be replacing for the third time in almost two years the axle seals to the right rear assembly...does anyone know possibly why i am having this continued issue??? the seal is not expensive, unfortunate for me it requires a new bearing everytime you replace a seal...now that is expensive...feedback would be appreciated? thanks john

Yoter

Check the valve on top of the diff. May be clogged.

wrenchmonster

Word. I think Yoter is right. Sounds like a plugged vent. Also check the axle and housing itself when you have it apart.

Yoter

The vent is one thing to check but are you really cleaning the housings seal seat good getting all of the dirt and grime out? also are you making sure you have the seal tapped in straight and all the way in? Also are you replacing the outer seal because that would be why your leaking still. The inner is the prime area to check when there is a leak being if it leaks it will make its way out. If the out seal dies the inner still holds if im not mistaken. how are you tapping the seal in? it is easiest to use a 2x4 and give it an even tapping surface imo. good luck.

SloPoke

I would tend to think it's the vent as well.

Why are you having to replace the bearing every time? That's a $50 part and if your just replacing the seals, you should have to install a NEW bearing. Hmmmmmm

mt_goat

Maybe a bent axle. Check for wheel wobble.

T-A-Z-M-A-N

thanks for the posts, i will ask the mechanic to check the valves? as for the replacement of the bearing its a must because to replace the inner seal you need to break through the bearing, so on seal results in two seals plus a bearing everytime, the repair costs me about 300 each time...

T-A-Z-M-A-N

i am going to ask about a bent axle that was my first thought? thanks

Unhappy99

The inner seal is what allows diff fluid to dribble out. The outer seal is just a dust seal for the relatively sealed bearing.

a) don't use Toyota seals. Get them from NAPA
b) replacing the inner seal does not require the bearings to be replaced. The hub/bearing assembly with axle attached removes from the axle housing as a unit. The inner seal remains on the axle housing.

replacing the inner seal

RockComa

Generally when a seal leaks it's due to bad bearings. Check the shaft as mentioned but something else to consider. Check the seat of the seal. If you had a bearing go bad and it wobbled around it could have scared the seat. I had that happen to mine so I took a dremel and smoothed it back out. 2.5 years later no problems yet

RockComa

Also why wouldn't you use Toyota seals vs napa. Napa usually has the best quality stuff from the parts store chains but you say it as if not to use a toyota seal period

Unhappy99

"Generally when a seal leaks it's due to bad bearings."

This isn't particularly accurate when it comes to 4Runner rear axles. Do a search here. Many, and I mean a whole lot, have leaking seals with very low mileage on bearings. Factory seals are either installed incorrectly, or are not very good quality to begin with. Mine leaked early in my 87's life, the bearings failed at 160,000. My 99 leaked at 30K miles, and I certainly believe the bearings are still good now at 70K.

The reason why I recommend NAPA seals is that since lots of Toyota seals have leaked, why would I want to put another Toyota seal in? The NAPA seals work.

Same logic I use on the warping Toyota brake rotors.

kyle_22r

i had a bent flange on my passenger side axle shaft when i bought my truck. seemed fine(albeit wobbly making me think i had a bent rim until i was on my 3rd rim on that wheel) until last summer when i noticed some gear oil seeping where the flange and the drum meet. started saving up money to replace it, unfortunately for me i didn't make it that far. when running to the store one day, out of nowhere, i started hearing a clicking noise coming from the rear end, and it started getting louder. i thought it was a bad u-joint so i replaced those...didn't go away. turns out that i had sheared 3 pinion teeth off. i think that the vibration from the bent axle flange wallowed out the seal causing it to leak, as well as making things go bad in the rear end.

the main reason people say to replace the bearing when redoing your seal is because typically gear oil has to get through the bearing to leak past it. this washes out the grease in the bearing and can make it go bad. however, i've heard if you're careful with a small pick, you can remove the seal and repack the bearing.

Yoter

Shouldnt cost you over $50 for the priceyer bearing others $8 for the seal and enough to top off the gear oil . there is even a write up on doing thos job. its easy, I wont pay a dealer to work on my rig. Even when engine time comes I will let my rig sit until I have swap parts ready to go. Not rebuilding this engine. But thats in something like 80,000 miles.