I dont' think i'm getting and lockup in my car in overdrive OR third. Doin 60 on the highway on lever ground with cruise set my RPM'* are exactly 2000 rpm. What are u guys running on the highway? I'm not sure my final drive so u all might be off a little. It'* a stock 440-T4 that i just rebuilt. Thanks.

wow i havent postest in almost a year hopefully i havent missed too much.....

as for your TCC, this may not help but its a start, is your engine running at operating and running at normal temp? The TCC will not "lock" to a 100% coupling until the engine/transaxel is warmed up enough, around 120 degrees is about when mine will engage.

also ive found that when the shifter is in 3rd (D) and cruise is set above 45ish mph the transmission will not go into TCC "lock". Only when in overdrive will it the TCC lock when cruise is on. This is for my 88, on my dads 93 the TCC will lock in both drive and overdrive while the cruise is set. the 93 transmission is newer "4T-60"

hope this helps, get back to us

I always leave the car in OD and it was at operating temperature (for my car at least) and going down the highway at 60 MPH steady. I can feel it kick into 4th but not lockup. The RPMs are a better indication that'* why i wanted people'* feedback on their cars.

No one'* got input? Someone must have had/has this problem before.

Had a Fiero that did that - 5 v to the solenoid (TCC command) but no lockup. I'd connect a trouble light or DVM and see if there is a command. 60 mph in 4th lockup should be around 1650 rpm. and tach should not move when you change the throttle position.

BTW the 4T60 is a 440T4, just a nomenclature change. 92 and later should have a 4T60E (electronic). L67 got 4T65E.

Well the rpm'* are between 2000-2200 and they do change with very slight throttle input. How do i check if it'* getting tcc lockup signal when i'm going down the highway?

heres how i knew mine was working. i woiuld be hauling butt down the interstate. 2700 rpm @78 mph. i would start to climb a hill, it would slow down to about 75-76, and then the rpms would jump to about 3200. later on in the hill, if that didnt do it, it would drop out of overdrive and roll out 4grand and some change. after topping the hill, the rpms would go back down to where they were before, 2700 rpm.

A better way to check:

Your car should automatically stop the TCC as soon as the brake is applied (as litlte as just enough to get the brake lights to kick on, which is so little braking that you wouldn't feel it while driving) is enough for the TCC to know to turn off. SO to see if its kicking in or not while you're driving, keep your foot on the accelerator as you normally would while driving and with your left foot push the brake pedal down ever so lightly. This should kick of the TCC and the RPMs should jump up instantly.

If this doesn't happen then your TCC was NOT engaged when you tried this.

Note: DO NOT remove your right foot from the accelerator pedal during this test as that would naturally disengaged the TCC and so you wouldn't be doing much of a test anymore.

ALSO: Be sure to GENTLY push the brake pedal with your left foot... you'd be surprised how much your left foot will slam the brake pedal just because it has never been used to brake before.. this is just a warning so you dont stomp the brake pedal when going 60 mph or whatever..

Let us know what happens!
mike diaz

When talking about rpm you really need to have a scan tool but with a 2.97 gear, 78 mph in od/lockup should be in the 2300-2400 rpm range and just a hair over 2000 at 70 mph.

My OTC 2000 has a indicator for TCC command (and what gear you are in) so makes this sort of thing easy.

I have wondered the same thing about my 90 SSE. I find that running if it is in OD and I go up a slight hill, not huge hill, and I have to press harder on the gas to keep speed, the rpms actually drop lower, yet the speed stays the same if not increases. Then once I am back on level ground and let off a bit from the pedal the rpms go back up.

I am running around 2,000rpm at close to 100 km/h ( 60 mph). When going up this hill I am between 90km/h and 100km/h and the rpms drop down to about 1,600 rpm, then once leveled off it goes back up to about 2,000 rpms.


So I guess I can get someone with the scanner to take it for a ride with the scanner hooked up and watch the tranny then? Cause if it never hits full lockup it will be burning more gas than really needed.