Having trans issues, please help!

[oakleafresin]

I'm hoping someone here will be able to help me! All the good people went here it seems

I've been having issues with the ole GTP that I THINK are symptoms of the PCS but maybe someone will tell me I need a new trans.

On mornings colder than roughly 32* the trans shifts VERY slow for the first 5 or 6 shifts.

On these same mornings, when accelerating from a stop, the engine will just rev and the car will move a tiny but and then suddenly the trans "grips" and takes off like normal. This doesn't happen very often.

Now yesterday I went WOT on the expressway and it refused to shift into 3rd until I let off the gas.

Also, earlier in the day, I was accelerating down the road and when it hit 4th (and TCC lockup), the RPMs jumped around a good 3 or 4 times over the course of a few seconds before settling out.

This all started last summer I think. I ended up modifying the tune to combat it. I put the old tune back on the other day and it shifts HARD. So I'm thinking it has gotten worse...

I raised desired shift time to .3 seconds for all gears and also lowered pressure across the board. This makes it manageable and doesn't feel like it is going to break as bad. But it does chirp the tires pretty bad during upshifts and it didn't do this before.

I replaced the entire accumulator assembly and put a brand new shift kit in and this helped a tiny bit.

Should I bother replacing the PCS? The trans has probably 60k on it. I'd like to put money into the engine but this definitely takes precedence over that.

Thank you in advance!!!

Click to read more...

 

[RICH17]

My guess is TCC solenoid

 

[SuperDaveGSE]

Like you were shown on CGP,

No Forward Cold, Neutrals at stops, Shudders on take off:

One of the most common problems I have found after the milege gets over roughly 60K miles. The scenario.... You are driving in traffic for a while OR your car has sat for a while and is a cold startup. You put the car in Drive range and it wont move, or if driving you come up to a stop light and in heavy traffic and the light turns green and SUPRISE!!! You are holding up traffic with a car that wont go anywhere. The most common cause of this problem is a worn out inner surface of the Input clutch piston. I will post pics soon so you can better understand why it IS a real problem. Once the inner sealing area wears it can prevent the inner lip seal for the piston from sealing properly. You may find that revving th engine up will finally get the car to move and it will BANG into gear. This is because the pump in the transmission is working harder and moving more fluid thus allowing the added fluid to overcome the leak which prevented the clutch from either initially applying or staying applied. From the factory the rubber lip seals that are used on the inner and outer sections of the input cluch apply piston are a Short design seal. The transmission repair service field has found that a Long style lip seal greatly helps against this problem and is what is included in aftermarket gasket and seal kits and is also what we use in our rebuilds. New seals from GM are still the short design and offer no benifit over the originals. Another area of concern that causes this is a boost valve in the valve body, not near as common but it can cause this problem on a lessor scale. If a fluid/filter service has not been performed in a very long time then a very dirty or plugged up filter can add to problems as it because a major restriction. IF the filter is found to be very dirty on the inside, which can be verified by cutting open the filter, then there are other problems inside the transmission anyways and an overhaul is the only correct way to fix the problem. Sometimes servicing a transmission with this condition will make the problem worse, so dont feel that you need to rush out to have a transmission fluid service done to make the transmission work like new again because it isnt going to.

I would change all the solenoids out just to be safe though.

 

[99PONTIACGP]

I had similar problems with my impala and it wad the speed sensor. I had the trans rebuilt.

 

[oakleafresin]

Like you were shown on CGP,

No Forward Cold, Neutrals at stops, Shudders on take off:

One of the most common problems I have found after the milege gets over roughly 60K miles. The scenario.... You are driving in traffic for a while OR your car has sat for a while and is a cold startup. You put the car in Drive range and it wont move, or if driving you come up to a stop light and in heavy traffic and the light turns green and SUPRISE!!! You are holding up traffic with a car that wont go anywhere. The most common cause of this problem is a worn out inner surface of the Input clutch piston. I will post pics soon so you can better understand why it IS a real problem. Once the inner sealing area wears it can prevent the inner lip seal for the piston from sealing properly. You may find that revving th engine up will finally get the car to move and it will BANG into gear. This is because the pump in the transmission is working harder and moving more fluid thus allowing the added fluid to overcome the leak which prevented the clutch from either initially applying or staying applied. From the factory the rubber lip seals that are used on the inner and outer sections of the input cluch apply piston are a Short design seal. The transmission repair service field has found that a Long style lip seal greatly helps against this problem and is what is included in aftermarket gasket and seal kits and is also what we use in our rebuilds. New seals from GM are still the short design and offer no benifit over the originals. Another area of concern that causes this is a boost valve in the valve body, not near as common but it can cause this problem on a lessor scale. If a fluid/filter service has not been performed in a very long time then a very dirty or plugged up filter can add to problems as it because a major restriction. IF the filter is found to be very dirty on the inside, which can be verified by cutting open the filter, then there are other problems inside the transmission anyways and an overhaul is the only correct way to fix the problem. Sometimes servicing a transmission with this condition will make the problem worse, so dont feel that you need to rush out to have a transmission fluid service done to make the transmission work like new again because it isnt going to.

I would change all the solenoids out just to be safe though.

See, the only issue I have with that is that it doesn't explain the hard shifting...

 

[PANDA]

Did you do a pan drop and filter change yet?

 

[oakleafresin]

Yes I did, fluid looked fine though. I also replaced the entire accumulator assembly (pistons and all) because there was a lot of wear in this area, especially the pins. This helped a tiny bit

 

[SuperDaveGSE]

Says it right in there...

"Once the inner sealing area wears it can prevent the inner lip seal for the piston from sealing properly. You may find that revving th engine up will finally get the car to move and it will BANG into gear. This is because the pump in the transmission is working harder and moving more fluid thus allowing the added fluid to overcome the leak which prevented the clutch from either initially applying or staying applied. From the factory the rubber lip seals that are used on the inner and outer sections of the input cluch apply piston are a Short design seal."