TCC keeps locking and unlocking at highway speeds

d0n_3d

Boost is good.
On my 86, I'm noticing when I am driving at highway speeds say 45-55 mph, the converter is locking, then unlocks, then re-locks, and keeps repeating this process. The trans was refreshed just recently and everything is mostly stock to my knowledge. All gear shifts are fine and quick/firm. Could I just eliminate the lockup by just unplugging the solenoid at the trans or would this cause problems?
 

blackmonte

New HP Technology !!!
Yep, mine does the same thing, but only when I let off the throttle.I asked a few people and said that was normal.
 

d0n_3d

Boost is good.
it locks and unlocks constantly when I am driving between 45-55 mph. when i go faster say 65, it doesn't seem to do it.....it stays locked......i wonder if the chip is at fault here........i don't even know what chip is in this car, i just picked it up 2 weeks ago....3-4 shift is firm and quick
 

wickedtt

Active Member
it locks and unlocks constantly when I am driving between 45-55 mph. when i go faster say 65, it doesn't seem to do it.....it stays locked......i wonder if the chip is at fault here........i don't even know what chip is in this car, i just picked it up 2 weeks ago....3-4 shift is firm and quick

You could have the chip reprogramed to have lockup come in earlier or later if you wish.
 

Real-T

Member
Also, just to rule it out be sure to check the brake switches underneath the dash on the brake pedal.

This switch disengages the lockup when the brakes are applied. If misadjusted or faulty they "could" cause what you are seeing......
 

Scott231

Mean Scott
These are all valid comments/questions. If the chip is the same one you were using before the transmission mod...guess where the problem is? :)

If not, check the comments already listed. There are plenty of TCC lock/unlock parameters in a TR chip.
 

S10xGN

RETIRED!
Could it be temp. related? The only time mine's ever done this was during a long (750 mile roundtrip) overnighter to Jakeshoe's place last Dec. and it was very cold (for us!) in the mid 30's and my truck runs pretty cold anyways...
 

d0n_3d

Boost is good.
That's a very good point............I did swap out thermostats and now run a 160.........my temps are between 155-160 on the highway even with a front mount intercooler.....I love my dual 12" Spal fan setup :D

So does the converter only lock up at a certain engine temp and not just based on vehicle speed?
 

JDSfastGN

Well-Known Member
mine will not lock until temps are above i think 150.... a few months ago i was driving late at night and it was in the 20s. The car wouldnt go above 145*.... and the Tc wouldn't lock either...
 
Top