So my brother in law had my blazer for a while and said the tranny went out. He didn't want to deal with it so I took it back. Shortly before I went to get it he says it's not the tranny it's the rear differential. We drove it on the trailer and back off and around the block in 4x4 no problem. I went to move it this morning and it would not go in reverse so I tried drive and when I hit the gas it clunked started grinding and didn't move. I'm not sure whether it is the tranny or rear diff. It's a 2000 blazer ls 4x4 with 235000 miles if that makes a difference. If anyone can give me some info before I bring it in or try to fix it thank you.

 

Sounds like the sun shell went out. In other words a rebuild or replacement.

 

No need to replace, rebuild with a beefier sunshell

 

I agree with TZFbird and NewGuy. sun shell... unhook the rear drive shaft and rotate the pinion to confirm that the diff's ok. Call around and/or check craigslist for a reman or good used, whichever fits the budget. I build 'em and post on CL for $900 rebuilt, repairs start @ $450. surely there's someone in your area that does the same.
Tranzman

 

I don't mean to sound stupid but what is the sun shell? My budget is kinda tight but it is necessary to fix so I will pay what's needed. I'm assuming if I try to find a used one I can look for s10 or the likes. So it shouldn't be too hard to find. Is there any tests to do besides taking the drive shaft out and turning the pinion?

 

Sun shell is an internal part of the trans that connects the rear sun gear to the reverse input drum. Go to www.wittrans.com and look at the blow up of a 4L60E trans. pictures are worth 1000 words. It is item # 624.

 

Thank you guys. I will get under the blazer this weekend. Hopefully it's not raining still. Is it hard to rebuild?

 

you`ll have to pull the tranny

 

If you have never done a trans before. You will need some special tools to get the job done. You'll be over whelmed with new everything inside of a transmission. Do some research before you decide to tear into it. Take lots of pictures. There is a lot of you tube videos on that will help you get through it. 35 year veteran trans-builder. I'll help if I can but I work two jobs.
Tranzman

 

I haven't done one before so I will most likely bring it in. I got it on Jacks today and the rear drive shaft spins in 4x4 and 2x4 but the rear wheels don't turn. As well in 2x4 when I push the breaks the rear drive shaft continues to go oh course because the wheels aren't being stopped. Making it clunk as I had mentioned earlier because I shifted out of drive while it was spinning.