Rear Wheel Seals Keep Blowing

boston97 · July 11, 2008

I have a 94 Silverado 1/2-ton 2wd extended cab pickup with 234,000 miles on it. I've replaced the rear wheel seals three times in the last 80,000 miles. This seems excessive. I've had the carrier and pinion bearings changed twice in the life of the vehicle and the current bearings have about 40,000 miles on them. Just last week, I installed new axle shafts, rear outer bearings and seals and within 1 week the left seal is leaking again! The seals were Timken brand from AutoZone. Is the seal quality better from GM or is there something else wrong? I checked the vent hose and is seems to be clear.

Chevymetal · July 11, 2008

I was told recently that Timken was outsourcing a lot of their production to china and the quality has dropped considerably. Just what I was told, but it def wouldnt be the first time I saw a brand new faulty part.

boston97 · July 12, 2008

I bought GM seals today and will be installing them tomorrow. The dealer service manager told me I was overfilling the differential and may be the problem. He said the oil level should be about 1/2" below the fill plug when the truck is at normal riding height. I'll make sure this time! Hopefully the problem does not return. The Timken seals were from china. The GM seals do not say where they're made!

I was told recently that Timken was outsourcing a lot of their production to china and the quality has dropped considerably. Just what I was told, but it def wouldnt be the first time I saw a brand new faulty part.

L29er · July 12, 2008

your vent hose may be clear but you need to use a pick or something small into the port in the axle, and see if you can get it in there, stuff commonly builds up in the axle port and can plug off, and the hose can be a- okay, there is no other reason that your seals should be failing this soon, your axle must not be able to vent.

C & A s Dad · July 15, 2008

Steve, my bet is you were overfilling it. GM (at least on my Yuk XL) recommends 5/8" below the bottom of the fill hole. This does not sound like much but it is enough to allow excessive gear oil to get to the seals and leak.