Cheap TCC lockup - not so good Experience

[MTTwister]

Just back from my raod trip - 3000+ miles. Evidently I wired the TCC lockup incorrectly, or the switch is faulty, but the resultant "high TFT" signal to the ECM caused problems, but not right away.

Initial symptoms were hard shifts, and a hard up- immediate downshift on acceleration. But - 5 days into the trip, I started getting a Serious Surging - random, and at various throttle positions. Immediately thought the TPS was going bad ( or bad injector, or bad IP again, or .....) Took it into a GM dealer in Lansing, MI, the tech got a contiuous High Tranny Temp code - with no MIL light - working just as prescribed, except that it was continuously on. :mad: I need to check that wiring soon. Disconnected one of the wires to the ECM and the problem went away - But That was some Serious Surging and Defueling. Scary (and Dumb Me not double checking the wiring before installation - thought for sure I had that resistor in line to the switch.)

Morale - don't run with the cheap TCC lockup on all the time, only when needed!

BTW - Rarely saw tranny temps over 175 either way (not towing)

[rjwest]

MTT, I posted my results last week.


DITTO on harsh shifts....
I only use as needed, and do not shift gears with engaged.. Did get a temp code once, I have a laptop with CARCODE prog, reset on the fly as soon as Yeller lite.

I think it came on at 2nd gear Very high PRM and shifted....( forgot switch,

Also ther is a delay in PCM set/ release of
Locked condition, have to time it...


REALLY makes a differance in tran temps......

[tanker]

Hmmm, I don't remember what I paid for my "BD" Torq-Loc, but in all the years I've had it, not one problem. I think that they only work well with the older 94-95 units. Howie E. has the same set up as mine on his 97 and had trans pressure problems, not temp issues. I think he has it under control now.
Sometimes our "cheap" things can and will bite us. ;)

[rjwest]

Just back from 4K trip with camper.....

TCC lock up works well if used at correct time.

Best at 40-50 mph on roads where speed limit/conditions prevent lock up from staying
on ( above constant 50mph) Leave it in 3rd and
locked.

When going above 50 , switch off shift to 4th.
Prevents harsh shift..

Also if TCC left on in forth , it will hold lockup
untill 3rd gear down shift.
i have it pretty well figured out with Boost gage where shift will occur..and swith off tcc and
do a manual 3rd downshift.

Also have used it in 2nd on long climbs, but
make sure switch off before shifting out of second.

Its like a manual automatic shift.

Does keep tran temps down.and pulls better.

Only code problem I have had was the Overboost
if I shift from 2nd or 3rd without Releasing
TCC and keeping boost to high, Boost really
overshoots when it shifts, got to get booost fooler working...

Plan to leave it installed. Thanks Mttwister.

[a5150nut]

What if you put a momentary contact switch (normaly open) on the floor board in the upper left corner. Like where they used to put the dimmer switch? Add an LED on the dash so you remember why your left foot is over there.

[rjwest]

Tanker, Had the BD torqueloc, Didn't work for reason stated. sets limp/harsh shift mode.
I think 96 and newer compares input to output speed
and flags error if not as expected.

Got 1 torq-loc sitting on shelf....

2nd gear TCC lock up is a "MUST" if you travel in PA.!!!!!!!!!!!