Is anyone experiencing or had experienced a rough shifting automatic transmission in their Monte Carlo? I have a 2002 Monte Pace car and when the car is driven around for a while and at operating temperature,the transmission begins to shift very rough through the gears from 1 to 4. Sometimes it shifts smoothly for a long time but other times it begins to rough shift after just a half hour of stop and go driving. Does anyone have any ideas of whats causing this problem and what the cost of the fix would be? I have a 3.8 with 68000 well taken care of miles. There is no cel when its shifting rough.

 

Mine is doing the exact same thing. EXACTLY. Only my threw a code because it started acting up pretty bad and it threw a Torque converter code

 

Thank you JW for your reply. Mine hasn't thrown a cel yet but I'm sure it will when it gets worse. I hope i wont need to replace the tranny. A fellow Monte owner told me that it may be the shift solenoid going bad on me....usually when they start to go bad it goes into a default mode were full pressure is used to change gears and the shifts get really rough but im not sure if thats the case with mine since the cel isnt on and for the most part it shifts smoothly until it get hot.

 

I would start out by getting your catalytic converter checked out, Someone on here told me yesterday that Monte Carlo's had a tendency to get clogged cats and they would cause the same issues we are facing.

 

I had the cat replaced last year at the dealer under warranty because of the clog issue but it still shifted smoothly even though the cat was clogged. I just had no power at all when it was clogged. I think its an issue with the shift solenoid but i thought that it would at least give me a code for that issue but it hasnt as yet.

 

If you have access to a scan tool, check for codes. Transmission codes usually will not activate the check engine light. Mine is doing something similar, and is setting the long shift\max adapter code. That is for a sioinoid in the trans. To replace it, most of the trans would have to be torn down.

I was told by a local trans shop, that I would be better off to just rebuild it, since it has to be torn down most of the way anyway. I think it was $800.00 to replace the part, or 1,600.00 for a rebuild. If you just replace the bad part, you would be kind of rolling the dice to see if the trans wasn't hurt in the first place.

 

WOW...not too many responses to my question about the rough shifting.....guess no Monte Carlo owners are experiencing this issue on a common GM transmission problem.I saw a pic of the solenoid that controls shifting and line pressure and it figures that its made out of plastic! No surprise to me of the quality parts that GM uses in their vehicles! No wonder they have so many issues with their products!

 

I have the same problem

Try replacing your TCC solenoid, shift solenoids, and pressure control solenoid in the transmission. The check engine light won't cut on for transmission codes, but they are stored in the PCM. Using a scanner, look for P1811 or P0742 or any codes in that range (P1800-1900 and P0700-P0800)

If that doesn't work, your torque converter's bad

 

mine was doing that......it was the shift solenoid.......and it showed up on code......if you shut the car off and leave it sit for awhile does it still shift hard?.....when the solenoid is faulty the computer holds the last pressure point which is high.....after it sits it resets ...for awhile....had it done on my monte and gran prix as well

 

After i let the car sit for a while and then drive it again, the tranny shifts fine until about an hour later while driving it starts to shift rough again..Dealer will not look into it until it leaves a code but so far no code in the computer so they say.