Thread: 2002 4T65E TCC RPM Oscillation

I have the TCC RPM oscillation issue with my transmission. I jumped the gun and bought a TCC PWM Solenoid, but am reading on Dave's '4t65e common problems' page that it is very rarely ever the solenoid itself. I wanted to chime in here to see if anyone else has had this problem and how they fixed it, also if it is possible to do it with the transmission in the car still (I would assume, just have to take side cover off and unbolt the channel plate as a whole assembly and work on it outside of the car?).

Here's the potential causes (taken from Dave's page):
- Excess wear in TCC regulated apply valve area
- Shrunken TCC apply valve end plug o-ring
- Worn/Shrunken teflon seals on the IS
- Bad o-rign on IS or seals in TC
- Faulty TCC
- Bad PC solenoid
- Worn out sleeve in channel plate that supports IS
- Dirty MAF (Wouldn't that be nice)

Some things about my transmission:
- It is in need of a fluid change. I have the Dexron VI and just bought a garage heater, so this will be happening shortly. Hopefully this will fix the problem, but I doubt it.
- Car does not stall when rolling to a stop, so the lockup disengages fine
- Trans does not run hot. When scanning and cruising on the interstate, it hits maybe 160F?
- I have never experienced TC shudder, but I am pretty sure my car doesn't have any of that.
- It is starting to get those sloppy/slow shifts when it is warmed up where it will lag for a couple seconds then slam into gear. Not hard, but definitely can feel it.

SES was set for P1860 TCC PWM Solenoid circuit electrical, but has since gone away. For a few days, I was getting absolutely no oscillation in RPMs. Car ran fine. Now today, it was pretty bad on my way to work, so I guess I should give it some attention.

Side note. Since transmission work is almost guaranteed, what else should I replace while there? I have a TransGo shift kit (should I have gotten a different one), plan on doing the PC solenoid, and 4th gear clutch hub.

Originally Posted by Nchristopherson

I have the TCC RPM oscillation issue with my transmission. I jumped the gun and bought a TCC PWM Solenoid, but am reading on Dave's '4t65e common problems' page that it is very rarely ever the solenoid itself. I wanted to chime in here to see if anyone else has had this problem and how they fixed it, also if it is possible to do it with the transmission in the car still (I would assume, just have to take side cover off and unbolt the channel plate as a whole assembly and work on it outside of the car?).

Here's the potential causes (taken from Dave's page):
- Excess wear in TCC regulated apply valve area
- Shrunken TCC apply valve end plug o-ring
- Worn/Shrunken teflon seals on the IS
- Bad o-rign on IS or seals in TC
- Faulty TCC
- Bad PC solenoid
- Worn out sleeve in channel plate that supports IS
- Dirty MAF (Wouldn't that be nice)

Some things about my transmission:
- It is in need of a fluid change. I have the Dexron VI and just bought a garage heater, so this will be happening shortly. Hopefully this will fix the problem, but I doubt it.
- Car does not stall when rolling to a stop, so the lockup disengages fine
- Trans does not run hot. When scanning and cruising on the interstate, it hits maybe 160F?
- I have never experienced TC shudder, but I am pretty sure my car doesn't have any of that.

SES was set for P1860 TCC PWM Solenoid circuit electrical, but has since gone away. For a few days, I was getting absolutely no oscillation in RPMs. Car ran fine. Now today, it was pretty bad on my way to work, so I guess I should give it some attention.

Side note. Since transmission work is almost guaranteed, what else should I replace while there? I have a TransGo shift kit (should I have gotten a different one), plan on doing the PC solenoid, and 4th gear clutch hub.

If you replace that fluid you're going to be in the same boat I was in...slipping 1-2 shift and worse TCC oscillation. Dump some Lucas trans fix in it and call it a day. If you want to change the filter, fine...but make sure you dump all the old fluid back in or you'll have to replace the trans.

I don't like the sound of that, that concerns me. I planned on dropping my L67 in and doing e85, so I'd like to put a 'reliable' transmission behind it. What ended up being the problem, was it in the valve body?

Originally Posted by Nchristopherson

I don't like the sound of that, that concerns me. I planned on dropping my L67 in and doing e85, so I'd like to put a 'reliable' transmission behind it. What ended up being the problem, was it in the valve body?

Valve body was worn out and too much clearance in the clutch pack. You could literally wiggle 1/2 the valves in the valve body.

Wow. If I knew I could get a TEP remanned for $1600 shipped, I would have done it a while ago. Unfortunately I now have two transmissions sitting in my garage, making it 3 is not an option lol.

So is this a notoriously annoying/difficult problem with these transmissions that I should just let it be and not even try to fix it?

Also, what kind of power are you putting through that transmission / driving style?