Transmission whining no reverse again

I’m having a similar problem from a year ago, and I’m afraid I may already know the answer. I wanted to see what others thought might be the problem.

Vehicle: 1999 Chevrolet Blazer LT 4x4, 164,147 miles, automatic transmission (rebuilt at 157,859)

Problem: Started getting a whining noise while driving right under the driver’s seat. I noticed that shifting from 1st to 2nd was occurring at higher rpm (2500+ range). I basically had to back of the throttle to get it to shift. Once it was in high gear it drove fine. The whining is still there even when in park. That was making me think it was the transmission pump. But….

My observations: I got it home and checked the noise with a small piece of pipe to my ear. It’s coming from the back end of the transmission near the transfer case. The car would NOT go in REVERSE. I had a similar problem a year ago. I was thinking the sun gear was out. In any case, I had a rebuilt transmission installed. That was at 157,859 mile (i.e. I only have 6288 miles on a rebuilt tranny). I drained the oil last night and looked for metal. There is the typical grayish sludge coating the magnet and a little in the pan, but nothing major. The oil looked relatively clean.

My plan for now: I’m going to put a new filter on and refill with fresh fluid. I wanted to see what others thought. I've read several posts with similar issues over the years. I'm sensing another rebuild in my future.

It's a good start, after ATF change, make sure the engine is at normal operating Temp, idle, and in the parked pos when checking oil.

It sounds like there wasn't enough ATF for the hydro pressure to do the shifting.

Just and update. I put a new filter and fluid in. It still whines and no reverse gear. It shifts into 2nd gear at high RPM's. I'm guessing its the sun gear shell that's stripped again. Looks like a tranny rebuild (or at minimum sun gear shell replacement..which still means pulling the tranny).

As a side note: I've enjoyed the information and feedback that I've gotten from this forum over the years. I've done everything from wheel hubs, heating core, intake manifold gasket, fuel pump, O2 sensors, radiator, idler arm, pitman arm, upper/lower ball joints, etc. Thanks to the information I found here. With that said...I'm done with my 99 Blazer and moving on to something new. I've already got an offer for this headache from someone more knowledgable and capable than me who loves a challenge. Thanks again everyone......

thanks for the reply. sorry your experience couldnt be better, but glad the forums were able to help. i know this place has saved my ass a few times. just a question though? have you had it scanned for codes? I'm guessin the warranty is done on the rebuild...

I’m having a similar problem from a year ago, and I’m afraid I may already know the answer. I wanted to see what others thought might be the problem.

Vehicle: 1999 Chevrolet Blazer LT 4x4, 164,147 miles, automatic transmission (rebuilt at 157,859)

Problem: Started getting a whining noise while driving right under the driver’s seat. I noticed that shifting from 1st to 2nd was occurring at higher rpm (2500+ range). I basically had to back of the throttle to get it to shift. Once it was in high gear it drove fine. The whining is still there even when in park. That was making me think it was the transmission pump. But….

My observations: I got it home and checked the noise with a small piece of pipe to my ear. It’s coming from the back end of the transmission near the transfer case. The car would NOT go in REVERSE. I had a similar problem a year ago. I was thinking the sun gear was out. In any case, I had a rebuilt transmission installed. That was at 157,859 mile (i.e. I only have 6288 miles on a rebuilt tranny). I drained the oil last night and looked for metal. There is the typical grayish sludge coating the magnet and a little in the pan, but nothing major. The oil looked relatively clean.

My plan for now: I’m going to put a new filter on and refill with fresh fluid. I wanted to see what others thought. I've read several posts with similar issues over the years. I'm sensing another rebuild in my future.

As an owner of my years worth of Blazer & Jimmy SUV's, I have been through this transmission issue a number of times, but only on the original trans. Most reputable transmission shops replace the weak sun gear shell with an updated heavy duty shell that will not strip as the wimpy OEM does. Once the transmission has been updated and rebuilt, the trans should be good for 200k plus miles. I would certainly complain to the transmission shop that performed the rebuild. Keep us posted.

Talking to orgional rebuilder may help getting a break on the job,,,lol,,,,the issue mainly is that part is the weak point in that trans,,,not so much an issue in the 700-R4,,,but the 4L60-E,,turns to a piece of crap!!!!!! there is several choices on what to replace it with.....OEM,,,,,The Animal,,,,The Beast,,,,Sonnex re-engineered......All are a good choice as long as "USED" is not in the mix.......Trust is the name of the game on what part replaces the damaged one.....,,,,chances are the only way to know is to be standing there when it is installed,,,then would you know the difference!!!!! If the shop can't inform you of the different shells out there ,,or lowball price,,,you might be in the wrong shop.......I do not understand why everyone is in a hurry to change the filter for a component failure,,,isn't the filter filtering all the oil,,,,NOT just reverse????,,must have stock in a filter MFG Co....... Just my babblings,,,,gbaum