Tranny problems?

[Trailblazer6]

My family and I went on a 100 mile trip. On the way there no problems. On the way back is a different story. So, went driving around lake Altus took a dirt road (trail) used 4x4 low and high. No problems. Got back to the highway put back in 2wd. Still no problems. Went to pick my wife up and was waiting for about 20 min in the blazer in park idling. Started to leave and we had no reverse. Tried drive, no problem all forward gears work. Decided we would get something to eat and decide weather or not to try driving 100 miles home. Decided to go for it. Tried reverse again no reverse but now it's grinding and clicking very bad. Start driving and before we get out of town It starts making clunking sounds
And going in and out of 3rd and 4th. Get out of town and as long as I kept
Slight pressure on the gas pedal and stayed at 40mph it seemed fine. If I let off the gas and got back on it would act like it was in neutral and start clunking and grinding. We got about 20 miles from Altus lost halfway to Lawton and just lost all forward gears. Coasted about 1/2 a mile going down hill and pulled on to the shoulder. Tried all fwd gears, nothing but grinding, clicking, acted like it was in neutral. Tried reverse and it went in no problem. Tried drive again and went in. Started driving again shifted normal and did fine all the way home. Tranny fluid is full and no warning light. I have no clue
What caused this. Any ideas? Never had an issued before. 157,xxx miles.

[Trail X]

Sounds like you got very lucky getting home. I wish I had more advice for you at the moment. Intermittent problems are very difficult to diagnose, and I almost guarantee that if you brought it to a transmission shop, they would tell you it needed to be rebuilt.

If you did not notice any slipping when the transmission was operating properly, then it may not be a clutch issue. It sounds most like you may have a shift solenoid going out. They are little valves that shift hydraulic pressure around in the transmission valve body. It sounds like you may have one sticking or getting a bad signal. When is the last time you flushed the trans fluid? Its possible that your fluid is so gummed up that it is causing things to stick. I would start with a fluid flush and new filter and replacing the solenoids (wish I could narrow down which one to swap out), and see where that gets you. These sort of problems rarely just go away on their own, so I'd expect you'll see it again if you don't take some action. Good luck, transmission problems suck.

[AA1PR]

is it in the transfer case

I once had what I thought was the trans going only to discover it was the transfer case

slipping in 1st & reverse was my issue with mine

wonder if the chain is worn in the transfer case & thats the noise you hear & the issue

best of luck

[Anthony Hernandez]

Bruce Jenner

[Trailblazer6]

Thanks for the reply guys. I'm about 95% sure the issue is the transfer case and not the transmission. I cannot get the transfer case to shift into neutral. I was messing with it last night. Some times the 4x4 will in gage and some times it won't. Lights on the selector switch will flash and then none of the lights will light up. Also when this happens the check 4x4 light will come one on the cluster. I checked the transfer case fluid and found exactly what I thought I would. Drained a little in a cup. Very fine metal flakes suspended in the fluid with large ones settled in the bottom of the cup. Also the fluid is black like coffee and smells burnt. I'm thinking it has never been changed and or the wrong fluid was put in it. If I can fig out how to post pics. I will get one of the fluid. Thanks again every one.

[Trail X]

Interesting. I hadn't considered that, but it is possible. It sounds like your transfer case motor wasn't working right originally, which allowed the engagement cam to slip (your transfer case motor lock circuit may have been the original issue). Once the TCCM locks down the motor lock, it doesn't check for slippage in 2WD or 4WD modes again. It does check for slippage in A4WD mode, so sometimes you can use that as a limp mode to still get around.

At this point, its possible that you chewed the internals of the TC up enough that its just not going to engage at all now due to the internal damage. You can either attempt to change out the transfer case motor, and do a fluid flush and refill and see where that gets you... or get a new transfer case.