TCC not locking at WOT

[VIN7]

Here we go again...

Background, low mile (3000 mile billet 9x11) converter, fresh EA stage II transmission. TCC locks up under part throttle conditions, will not lock up at WOT.

Pull converter and send to to Bruce. I talked to Rusty at TCS and he said converter clutch looked fine but went ahead and replace clutch, conical, etc.

Reinstall, but this time I took out the checkball in the input shaft. Same thing!!! Part throttle lock up, not wot lock up. I even took off the wastegate rod to see if I was overpowering the TCC, still no wot lock.

One thing I noticed...at part throttle (enough to raise line pressure via TV cable) the TCC won't lock. Low tps (cruising) and the TCC will hit hard.

So it seems to be pressure related. Can some describe the fluid circuit? I know the TCC locks by evacuating the fluid from the clutch. Is there something I could check in the TC control valve that could possibly be associated with this problem??

Thanks,
Mike

 

[VIN7]

Is it possible for the tc control valve to be installed upside down in the pump? If so can someone look at the fluid paths to see if it could cause my issue?

Uugghh, I think it'll be a dexron shampoo tonight.

Mike

 

[HighPSI]

Have you tried manually locking it up via the ALDL and then squeezing into the throttle to see what happens?

 

[VIN7]

Yes, I also have a manual switch and can lock/unlock it at will under light throttle. If I lock it from a standing start I can go back and compare logs to WOT unlocked and the rpms/speed match so it doesn't lock with a manual switch at WOT.

Mike

 

[SSedan64]

Lockup Solenoid Tutorial

Mike, does this help you? >> http://www.turbobuick.com/forums/transmission-talk/260404-lockup-solenoid-tutorial.html

Todd

 

[VIN7]

Todd,

I've had this issue for a long time. I have searched hours and days for something like this. I don't know how my searches came up empty, but THANK YOU!

Now I have a better understanding and can see that a slight bind that keeps passages partially open may be able to cause what I'm going through

I now hate transmissions once again thanks to all the dexron that has soaked into my skin last night, but I did disassemble and stroke the tcc control valve and replaced the solenoid oring so maybe I'll see some results.

Mike

 

[shifty6]

TCC l/u

Mike, Ensure that the wiring from your l/u solenoid to the 3rd & 4th gear switches (and the switches themselves; on the side and the bottom of the VB respectively) are functioning properly. These switches control communication w/ECM when to ground and allow l/u to occur. HTH.

Larry