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My Transmission is starting to upshift and down shift real hard, And when it does the rpms go high then it shifts hard and when in idle after it has been acting up I can hear a high pitch sound coming from around the transmission. When I turn the car off for alittle while it shifts normal, like it has reset or something from sitting. It does it when you least expect it and then I can go a week with out it doing it, but now has done it for the past few days. Has anyone had this problem? and now added to this, When I turn right only going up a driveway or incline I hear a loud pop on the right and sometimes a double one. I guess this is going to be an interesting month...

Pressure Control Solenoid is the hard shifts, IMO.

Your popping would be a suspension part. I have that and its my strut mount/bearing on the passenger side.

TransGo shift kit to see if that will work around your failed PCS. It did on my Buick's 4T65.

The 05 should for sure have the upgraded PCS and everything, though, which is weird. I'd do a pan drop and filter with some Seafoam TransTune beforehand and see what happens.

Upgrade doesn't mean it's not a bum part.

Eh, new ATF and filter will help a lot.

ok so I am having a similar problem with my 2000 bonneville. I could not figure out which transgo shift kit I would need (I dont know what tranny is in the bonneville) and also I see that the solenoid is not all that expensive but how difficult is it to replace? I have decent automotive know-how (brakes, oil changes, trans flushes, and other rather "normal" maintenance issues) So I think I should be able to handle it, I just want to know what type of time slot I should allow for this, or how long should I tell my wife I am going to be, "working on that *dang* car" Thanks to anyone who can help!!

brownbrentm wrote:ok so I am having a similar problem with my 2000 bonneville. I could not figure out which transgo shift kit I would need (I dont know what tranny is in the bonneville) and also I see that the solenoid is not all that expensive but how difficult is it to replace? I have decent automotive know-how (brakes, oil changes, trans flushes, and other rather "normal" maintenance issues) So I think I should be able to handle it, I just want to know what type of time slot I should allow for this, or how long should I tell my wife I am going to be, "working on that *dang* car" Thanks to anyone who can help!!

viewtopic.php?f=18&t=3230&p=31349&hilit ... oid#p31349

ANd I know theres another thread with pics of it being done, but I couldnt find it quick.

so that looks like it pretty much sucks balls. So you have to remove the case to get to the PCS? Yeah, uhhh, not for me!!! I will pay someone else to do it, lol.

robjr69 wrote: When I turn the car off for alittle while it shifts normal, like it has reset or something from sitting. It does it when you least expect it and then I can go a week with out it doing it, but now has done it for the past few days. Has anyone had this problem?

For about a year, I had the exact problem come up intermitentely when driving hard on hot days. Turn off engine for 15 seconds and its goes away. Sure sign of a PCS issue (due to it's problem determining correct pressure under high heat, imo)

I installed a 180 degeee thermostat first before considering more expensive solutions and I haven't seen the hard shift in over two years. If it comes back I'll get a shift kit.

Thought I'd suggest a less expensive possible solution to try first.

Thanks Guys for all your help. My car has been at the dealer for 2 days and all I get is "well its being looked at and the mechanic got some code from the transmission" I just called the service advisor and told him to pass along to the mechanic that cannot seem to find the problem what it might be. from what I have read it sure is a job replacing it. Im glad I have a warranty with a $50 deductible.

Well I got my car back last friday and so far so good. They got codes from the transmission that there was slippage. They came to the conclusion that it was the PCS so they replaced it. It was $70.00 for the part and $712.00 Labor.

So you paid $50 with your warranty? Good deal there!

no kidding ^^^^^

I experienced the same thing for a year or so. Lucas tranny fix after a fluid change helped quite a bit for a long while till my 4th output shaft finally bit it and I had the whole thing rebuilt for 1800