getting a parts list together for the blazer, one item im replaceing is the rear axle oil seals. was at the autozone site and it seems there are 2 major possibilitys, a 10-1/2 ring gear or a 9-1/2 ring gear. when i tried to do a search here i found references to a 7.5 rearend or a 8-point something rearend. heres what i do know: its a '97 ls 4 door 4wd, 3.42 gears, open differential, drum brakes. came with 235-70-15 tires oringinally. when i replaced a front differential seal last fall i ran into a situation with the wrong seal, ended up needing the "larger" one. any for-sure idea what rear axle i may have? i know theres some #'s on a axle tube under there somewhere, think its on the r.h. side on the backside but havent gone sanding the rust/scale off to find them. even then it may just give me some "code" to be decoded. i defitely dont want to skip this seal job, l.h. side is letting some oil by into the brake drums. but with 175,000 miles i guess its time. thanks. on edit: just went out and crwled underneath, no tag, has 10 bolts on the cover. 'spose i'll just have to get 2 sets of both kinds and hope that one set is correct. you would thin for such a common vehicle thay would have just ran 1 type of rear axle and have been done with it. heck, a camaro rear end would have worked.

 

It is lost likely the 7.5. It either that or an 8.5 which was very rare to find on a non ZR2. An easy way to tell would be to take a tape measure and hold it up to the cover.

 

o.k. thanks.

 

The GU6 3:42 with the 8.5 is what you have,but check the sheet in the glove box too!-Actually,I find these axles most common...

 

im sure i have the 7.5, based on pic ive seen of both, the 8.5 is more of a round shape, mine appears to be more oval. what puzzles me is no matter what auto parts vender i look up, im refered to a "c" or "k" in the 3rd postion of a number stamped on the axle tube. see link, #3 and #4 on list http://www.napaonline.com/Search/Res...+50014+2014003 ive yet to locate this number. maybe when the weather is better i can do a better job of looking. or just tear it down when the time comes and take one of the old seals with me to the store. ended up doing that with the front axleshaft seal, first one i got was way too small.

 

I would take the VIN to a dealer and see if they can tell you what one you need

 

just call the local gm dealership and tell them
your looking for a rear axle and they will
get your vin and they can tell you everything
including part#S ive got a rare breed a 2001 blazer
2 dr 5speed manual tranny 30 spline axle 28-13/16 long
gm part#26058079