1989 GMC Van, 3/4 ton, 5.7 l (350 cu in) engine, conventional differential Hi, I opened a differential because there was a whining noise when cruising at 80km/h. I found one of the pinion gears has a broken tooth and several others teeth are pitted. I took both pinion gears out, the other looks fine. I also checked the side gears (the ones driving the axels) they seems fine as well a crown gear. I phoned around and I was told by GMC dealer that they sell an o/h kit for $ 1,000.- but non is available across Canada! They suggested to ask an independent "rear end" supplier to get a pinion kit. Do I have to replace all gears at once or is it ok to replace only the damaged one? Also do I have to adjust/shim some clearences? What to watch for? Thanks for a reply! Danigo

i did some looking around and i am getting this answer, catalyst system efficency below threshold bank 2, so im not sure what this is, some are saying its an o2 sensor and some are saying the cat convert might just be bad, so im at a cross roads cause i would like to Doit myself, i got under there and i see every thing, just not sure wich thing i should rip out, please help.....:wall: