Quick Tech: Leaking Axle Seals Suck!

Our 2000 Toyota 4Runner has seen quite a bit of off-road action since it was acquired two years ago. From Johnson Valley to Las Vegas to Ocotillo Wells, there have been some hard miles put onto the SUV. One of those miles was particularly fateful and resulted in less-than-ideal braking power, as well as squeals that couldn’t be ignored.

A trip to a brake service shop diagnosed the problem as the left rear drum brake. It turned out that the axle seal on that side had gone bad, and was leaking gear oil all over the brake. This was compromising our ability to stop effectively, and had to be dealt with soon or else it could lead to a broken brake drum. Better that we found this out now, than at some later date while out on the trail.

Armed with the knowledge of the problem, we made a call to the local Toyota dealership parts center and ordered the inner and outer axle seal, as well as the o-ring between the bearing and hub, and a brake gasket for the brake drum. The outer axle seal and gasket were more of a “just in case” purchase (as it turns out, we didn’t need them).

First, we removed the brake drum to expose the inner components. Grease had collected on everything, so we hit it with brake cleaner before moving on to the axle shaft, which we removed. The oil drained out, and then we proceeded to remove the old o-ring and chip away at some surface rust that had accumulated.

We grabbed our bearing removal tool and went after the inner axle seal. It came out after some effort. We cleaned up the inside of the housing end and broke out the bearing installation tools, picked the correct one, and then hammered the bearing into place inside the axle housing. Afterwards, the axle was slid back into place and the repair was complete.

Next to happen will be replacing the brake pads on the drums, as they have worn down unevenly and are still squeaking when coming to a stop. Still, we’re glad to know this fix was done in time before something worse happened further down the road.