Ive replaced the rear pinion seal twice with after market seals from AutoZone and Pepboys ... I still have a leak ... enough that the under carriage gets coated and dripping after a days use

I noticed the original seal loooked a bit different than the replacement - lip was a bit bigger

any tips - help
OEM part number or suitable replacement ??

2002 Chevy Blazer 7/58ths ring 3.42 ratio
thanks in advance

 

You may have a groove worn in the yoke. Were you cleaning up the sealing surface on the yoke each time? Are your pinion bearings still good?

If you know any good machine shops, they should be able to turn down the yoke and then sleeve it turning it back down to the proper size and surface finish for the lip seal.

 

If the yoke has a grove worn in it check to see if the auto stores have a repair kit. I don't know if they make them for the pinion seal. They do make them for the front crankshaft harmonic balancer. It is a thin metal sleeve that slides on giving a new surface for the seal to ride on and it comes with a new seal.

You need a smooth non groved surface for the seal to keep it from leaking. Your other options are a good used yoke or a new one.

 

the yoke doesnt seem to have any groves in it .... Im going to try to get a replacement seal from the Chevy dealer this time ... like I stated the replacement seal I got doesnt seem to be the same as what was in there before.... thanks

 

OE # 26026792 is the pinion seal showing an application for 7.5" and 7.625" rear axles from the mid 80's up to 2002, but it looks like there may be two different seals available for 2002 trucks. I would contact your dealer for the current PN and pricing. MSRP on the later seal is ~$11 from the dealership.

 

Is there any movement in the Yoke whne it's all put together? Could be a worn Pinion Bearing causing the Pinion to move around. Hense the leak.
It's not unusual for the Nut on the Pinion to loosen. an 1/8th of a turn goes a long way. Have you notice a slight whine coming from the rear that comes and goes depending on whether you are accelerating or decelerating?