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1999 Pontiac Montana Transmission

My '99 Montana has had two separate episodes of rough upshifting between 1-2 and 2-3. No warning lights, overheating, or weird sounds. I’ve seen several old posts about this problem and wondered if anyone has reached a solid conclusion as to the cause.

There are lots of reasons that you can get hard shifting. So there isn’t “a” problem with “a” cause.

Clue people in on the mileage on this transmission as well as its service history (fluid/filter changes). Also report on the condition of the transmission fluid - level, color, and smell.

Also try to describe the problem in more detail. What is an “episode?” Why did you mention only the 1-2 & 2-3 - is the 3-4 shift ok? Or perhaps is there no 3-4 shift at the time?

The best thing to do for help would be to have a transmission shop scan it for codes - there are transmission codes that can be stored w/out a check engine light. There are shops that will run codes for free. Others might charge an hour labor or so. You can just call around.

If you get codes you can post them up here for comment.