2005 Chevy Trailblazer tranny
 

Daughter just bought a used one and it doesn't always shift from 2 - 3. She can manipulate it by throttle and manual shifting and sometimes it will change. It is an automatic.

Anyone with experience ? Thanks. Don't want her ripped off by tranny shops if possible.

How's the fluid level? Condition? How many miles on this thing? What transmission is it? We need more info in order to give you input.

Can't say what I don't know. ;) Fluid was 2 quarts over full and looked fresh ?

It's a 4WD but no idea of the trans model. 130,000 miles. So far on other forums advise to disconnect battery cables and clean all connections, short them together to reset computer, check both shaft speed sensors.

I am 1500 miles away until the 25th when I go to Fl and might get to see this rig. Have never been inside an auto tranny. Will pursue needed info,Thanks

Some numb-skull overfilled it: Drain it to where it needs to be and the problem will likely go away.

If not, the electrical reset tactics are a good next step.

If that doesn't work, I would say based on the fresh looking fluid that the previous owner noticed the problem, changed fluid, problem didn't go away, so they dumped it before the tranny went out.

Fluid was drained to proper level. No change. Feel same as you about dumping before problems. Will update when I talk with Daughter. Is it possible really dirty filter and low pressure ? Thanks

Low pressure and it would have a lot of hesitation. Low enough pressure and it wouldn't move at all. My guess would have to be the transmission itself is bad if it isn't an electrical deal. Maybe the valve body? I'm not a tranny guy (especially autotragics), but I know most trannies the valve body can be changed just by removing the oil pan.

Yes, really dirty oil filter = lots of friction material in filter = trans is likely beyond saving. A filter change might restore some function, but it's on the backside of life.

I have been DIY all my life, and just don't have confidence in Tranny shops. It can't be all that difficult to rebuild one, what with all the youtube videos out there. I just can't lay under cars anymore after all these years.

I had a 04 Envoy, I sold it with 165,000 on it and it still shifted like a dream.
I read it was a Corvette trans with a different tail shaft to accommodate the 4WD and the parts interchanged, there was a shift valve upgrade most were doing that acted like a shift kit.
Check out Trailvoy.com forums, there's tons of information there and I used it like a Bible when I had mine. Those guys were really sharp and knew their stuff.

Been to that trailvoy forum. Good info. I'm phishing for more inexpensive ideas before going inside. Need to go back and do some more reading.

It's now leaning toward an electrical issue. Previously, the fuel gauge was defective. Suddenly, it's now working. Also, oil pressure sender suddenly went dead. She changed that and it is now working. It WAS leaking a little so needed changing.

A manual transmission, yes.

Automatics are a whole different animal. There are hundreds of little parts inside of an automatic, and put one thing in wrong and it may not work at all. Find a transmission shop that's certified to rebuild it and put a warranty on it. There's one in my area that is certified by all 3 of the big 3, and if he rebuilds a tranny from one of them the respective auto company puts a 5 yr-100k mile warranty on the rebuilt tranny.

Did not realize a shop could get that certification. Probably will end up going that route. Thanks

Update

Did a tranny shop exam and had the thing rebuilt. Was mostly gummed up. New parts added as needed.