I.m sure you meant 140kmph not 140mph.Chico

My fiance's 97 GTP did the same thing. It started shifting real hard into second and hard, but not as hard, into 3rd and drive. The problem was a bad pressure control solenoid in the transmission. They replaced the solenoid and the valve body in the transmission and it cost about 800 bucks. 2.5 years later and its doing it again. Check out this link below. It describes the problem as well. The pressure control solenoid is about 50 bucks and its a 5 hour job to change it. If thats the only problem you're looking at about 400 bucks. The solenoid acts up more as it gets hot which explains the fact that you have to drive it for a while before you see the problem.

http://autorepair.about.com/library/faqs/bl895g.htm

i've noticed mine will sometimes not shift until 3500, or 4 grand without performance shift if im feathering it it only does it the odd time and sometimes it feels like it wont shift at all

I have never had any transmission issues with my car until last week when I had a place flush my tranny fluid and change the filter. My car has 110,000 and I have driven them all. Now when I am stopped and hit the gas the car shutters or shakes like the wheels are spinning but bouncing but I dont think they are spinning. I dont have any other issues with shifting any gears just this from a stop. Can anyone help me?

First check your transmission fluid level. Was that the first time you have ever had the tranny flushed? Have you done tranny fluid filter changes regularly or was that the first time? It's not advisable to have a neglegted high mileage tranny flushed. Only filter change and fluid topped off. Otherwise you just might open a can of worms. I hope that's not your case.

Transmission fluid should be changed every 15k-30k miles. Letting a tranny go too long and doing a flush is asking for trouble, because the fluid being pressurized through the system flushes clutch material buildup out of the lines/cooler into your tranny. I have no doubt that my tranny problems are linked to user neglect and could have been prevented if the past owner had regularly flushed or changed fluid. Most people know to change their oil and perhaps coolant. It seems that almost no one knows they need their tranny fluid changed or that it needs to be completed before their user manual says so.

well, i am going to go ahead this weekend and change the fluid and filter in the tranny. with the car having 71k on it, would this be the best thing to do at this point, or should i go ahead and look into having it flushed completely? also going to go ahead and do a t-stat change and coolant change while im at it. will get back and let you guys know if this fixes any of the problems.

thanks for the link jmahnke. hopefully this wont be the problem, but i guess i should keep that thought in the back of my mind huh.

No flush, filter/fluid change only imo. Just be sure to warm up the tranny by driving it for about 10-15mins before you change it, that will suspend anything in a fluid so it can be drained out. The hardest part on mine was getting out the old filter seal. They have a tight fit.

Anyone know if we can do the tranny line disconnect and start the engine to drain the fluid from the tc? I never really looked into it, but that would be the next best thing to a flush if we could, especially for those of us who have already installed a new filter. It would allow a total fluid change without the worry of forcing crap out of the lines and into the tranny.

Thanks for the replay Hercman. Unfortunatly this is the first time I have had the fluid flushed. I would change the oil regularly and coolant but not tranny. I checked the level by having the car running in neutral and it was just at the minimum at the bottom of the min to max box. I drove to work today and was unable to recreate the problem. When it happened yesterday it was at the end of my ride home. I dont know if it may have been heating up or if I just have to top the level off. I am going to bring it by the shop that worked on it today after work.

Thats along with doing a flush, i would not recomend doing that either, if you have a LOW millage or well taken care of tranny you can get a flush but on a HIGH millage or a tranny that has 70K with never doing a flush or regulare fluid change could result in a LOT of problems, i would recomend the basic filter change, then top off the fluid again...

before i get started tomorrow, just a couple more question. most of you guys have recommended using synthetic fluid, are there any problems associated with a fluid change and refilling with synthetic. since all of the old fluid will not be drained, will there be any problems mixing the two? what about additives? should i add anything else when doing the change or stay away from any other additives all together?

well, let me say thanks to all the guys that had input on my problems. thanks herc, pulled all the info needed to do the necessary fluid changes from your site.

ended up changing trany fluid and filter, coolant flush, new plugs and air filter, new t-stat and an oil change on lil sis's GP today.

everything went great up to the point when i put the tranny pan back on and then all things went wrong. sent mom to town to get a torque wrench for the pan bolts, came back and i didnt have an adaptor for the 10 mm socket so had to go buy one. got back and went right back to work and snapped off a bolt for the pan. i know what ur thinkin, but it happened, 10Ft/Lb right!! called Autozone to see if they had the bolts, which they did. so i decided to go ahead with the oil change while i was under there. it was really windy today so i held the drain pan up to the bottom of the car to prevent spillage, ended up spilling oil everywhere, then dropped the whole thing trying to keep from spilling more. ended up with oil all over the driveway, so much for the catch pan that i bought today to keep from getting tranny fluid all over the driveway.

got the new bolts, put them in and snapped another of the old ones. should this be happening and should i replace them all at this point?? got it all together and took it for a test drive and..........still shifting hard. what next?? any ideas? does it sound like time for a tranny rebuild or is there aomething else i can try? has anyone else had a problem with the pressure control solenoid as jmahnke suggested?

Sorry about your luck.

I thought it was just me, but to get a lb/ft torque wrench to be accurate at such a low setting almost made me strip out my Throttle Body. I tried putting 8lb/ft on my TB studs and I swear I was going to pull the stud right out.... I never heard the click, but I've got a pretty good feel for what a bolt can endure before breaking, or pulling out.
I use an lb/inch Torque wrench when I do tranny work. The 1-2/2-3 accumulator housing bolts are 97lb/inch and the pan bolts are 120lb/inch. Theoretically the lb/ft conversion would be 10lb/ft, but with our experience, it seems that such a low setting on such a big wrench is not a good idea.

For low ft/lbs, you use an in/lb torque wrench and multiply by 12. Much more accurate. I personally didn't use on at all on my tranny pan. I just snugged them all, then gave another 1/4 to 1/2 turn. No problems so far and it's been months ago.

As for next stop toward fixing the problem, try jmahnke's suggestion with the pressure control solenoid. They've been known to go bad on our cars. Labor shouldn't be too bad seeing as you can do it just by pulling the left suspension and not dropping the tranny. The part itself is around $40. If that fails, it's rebuild time for sure.

i just found out that one of the guys i work with was the tranny guy for a local gm dealer. gonna run it by him and see what he can do for me. sounds to me like that will be a fix for someone who really knows what they are doing. i can handle all the minor maintenance stuff, but dont think i want to tackle that one.

thanks for the advice on the in/lb torque, will have to keep that in mind when i get around to doing my car. will keep you guys posted after the next fix.

thanks