Trans Question

Been a while since I could login. Changed divisions, and had to get myself around the tighter browser controls at this office. :evillol: Anyway, here's my question. Had the transmission fluid & filter changed at 55k. Under one very specific situation, the transmission will hesitate upshifting sometimes. When the truck has been sitting at work all day, when I leave the parking lot, it will sometimes not upshift out of second. But only if I am driving normally and not punching it. If I floor it from the stop sign, it shifts up all the way through the gears just like any other time I floor it. But if I just accelerate lightly, as in normal driving, it will not upshift unless I flutter the gas or come off completely then accelerate a little harder. Only happens about half the time, and literally, I have ONLY had it happen leaving the parking lot at work. It's fine when it's cold after sitting overnight, fine everywhere else I've parked it for a few minutes or a few hours. I suspect the fluid level is either too low or too high, and something about the angle of the parking spot I always take, but maybe I'm way off base. The fluid level looks like it might be a little high, but I'm no expert on how that would affect it. When they stick in a gear and it IS caused by fluid level, does that normally happen with low or high fluid? Any other things I should check?

55,000 is too late for the FIRST atf and filter change. There could be lots of metal shavings, etc. from the first few break-in miles. I did mine at 50,000 and the trans died at 85,000.

With an add-on cooler and Mobil 1 ATF the second one (built by top local shop) went another 215,000.

Now using Redline D4 ATF and shooting for over 300,000!

It wasn't the first change. It was the first one I did, but I am not the original owner. Service records show one around 28k, and the fluid looked great. I'm just worried they overfilled it or something since it is now doing something it did not do before.

It wasn't the first change. It was the first one I did, but I am not the original owner. Service records show one around 28k, and the fluid looked great. I'm just worried they overfilled it or something since it is now doing something it did not do before.

On the fluid level always check after good and hot or after a good 15-20 mile drive.
Engine running in park.

Several thing could cause it to act up a little.
Gear selector switch/engine or transmission sensor/lose wire or plug in.
First a good transmission/engine scanner may show a problem or stored code past or history or present.
Could even be a engine sensor acting up.
Remember the engine has to be running good for the transmission to work good.
And some times they have PCM/VCM re flashes to cure some problems.
Have your dealer check for PCM/VCM re lashes and TSB's on it.
Good luck
MT

i have a 2000 z71. is my transmission pan deep or shallow? the guy at autozone couldn't help me. i need to know so i can change my fluid.

i have a 2000 z71. is my transmission pan deep or shallow? the guy at autozone couldn't help me. i need to know so i can change my fluid.

Welcome to AF.
With a new problem or your problem it is best to start a new Thread or post.
You could have either on but I would suggest you go to the dealer and get a good transmission filter.
They can run your vin and give you the right on for it.
And remember it it has the good thick hard rubber pan gasket it is resuable.
MT