Lost lock up after new trans install

[robzombie]

I will start off by saying that I had lock up before trans was rebuilt, and after rebuild during test drive.

I didn't have lock up initially on test drive but when I rested my hand on the shifter and moved it slightly forward it locked, and when I pulled slightly back it went out of lock up.

We went back to the trans shop to adjust the linkage [trans builder was in car with me for test drive] and found that it was out of adjustment. It would start in OD not neutral like it should.

Any how we adjust linkage so it starts in neutral and verify that reverse lights come on in R and all seems well.

Take it for another test drive and can't get lock up no matter how I nudge the shifter like earlier.

I figure I'll fix it when I get home as it was a long drive from the trans shop, NC back to SC.

I've read all I could find and have done the following so far. I have power at ALDL pin F [top upper left] and shorted to ground with switch and still no LU although I hear it clicking when IGN on and engine off testing.

I forgot to mention that we did this on a test drive while at trans shop [he jumped it with a paper clip while I was driving] and it did go into LU.

He told me it might be the 700r4 trans filter grounding on the fourth gear switch but I'm reluctant to drop pan yet as it had L/U when we switched it at ALDL before I brought it home and also when linkage was out of adjustment.

What if anything am I missing or overlooking in getting the L/U to work??

Could it be a valve in the trans or solenoid [even though I here it clicking when testing] but not locking when driving.

I highly doubt the brake switch as it was unlocking when I hit the pedal when we had it working before adjusting the linkage.

This is with a new converter [that works] and fresh rebuild on trans.


Any help would be appreciated, thanks ROB

 

[86 MCSS NA]

Not much help, but I remember reading/hearing about there being 2 different switches for 86 and older/87 and newer transmissions. One was N/O and the other was N/C but I don't remember which.
Just thought I'd mention it although you have said it worked initially so that probably isn't the cause.

 

[SSedan64]

Make sure you have good Engine & Trans -Grounds. If the Shift Cable is creating the Ground path it can cause all sorts of trouble/problems. You could run a Temporary -Ground wire to the Trans to check or
to check for the Cable creating a -Ground, open door & move shifter back & forth, dome light will usually flicker if it is.
trouble/problems = Broken cables, no Lockup etc...
It could also be a bad TCC Solenoid, even new ones are known to crap out. Or the 4th Pr. Switch grounding.

 

[robzombie]

All grounds are good, and although I hear the solenoid clicking when I test it I will probably replace it if I can't find the problem elsewhere.

 

[SSedan64]

Check the TCC Apply Valve in bottom of Pump for binding/sticking etc.. while you're at it if replacing the TCC Solenoid.

Lockup Tutorial >> http://www.turbobuick.com/forums/threads/lockup-solenoid-tutorial.260404/

Mo Info >> http://www.sonnax.com/product-lines/transmission/parts/1803

 

[robzombie]

Thank you SSedan64 for the info,I will check my trans tomorrow as I have a day off.

I will let you know what if anything I find.