Replaced trans auto O/D with factory GM Reman, the torque conv clutch locks up differentthan original trans. With old trans when it locked up the RPM's dropped about 300 to 400 rpm's, (at 60 to 70 MPH on level road) with new trans it drops about 100 to 200. What is normal?
Is the lock up of the torgue conv adjustable with the ECM with proper lap top computer?
1994 Camaro Z28 LT1, with auto overdrive, 88,000 miles
Does anyone know what the RPM's should be at 65 MPH with converter locked up? with standard axle, I believe is 3.23,

 

This is a function of how tight the torque converter is. Meaning that the old converter was a little more "loose" then your new one is right before the lock up. IMO nothing to worry about. In fact a you would expect a new converter to be tighter then a high miles one. Even just new fluid could change it 100 RPMs.

A tuner can change when the Torque converter locks up but he can not adjust how much the toque converter is slipping right before it locks up.

 

69 has a link saved to convert mph to rpms. seems like mine was about 1700 at 60 with the 323s if memory serves.

 

Thanks for the input.
This weekend I was able to get the car out on the open road. This is how it works: At 48 MPH the torque conv locks up, RPM drops slightly, at 60 MPH the RPM is 2000, touch the brake and the RPM go up very, very little. At 70 or so touch the brake and the RPM change is even less. With old trans for 10 years the RPM at 60 was about 1700 and at 70 or more just a little touch of brake and the RPM would go up 300 or so. With new trans the lock up conv is almost not noticeable and RPM is higher.
The electrical TCC is working.
For the conv to lock up correctly does it need certain fluid pressure to maintain a lock up? Could fluid pressure inside the trans be the problem?
Thanks again

 

woh,,, at 60 im at 2100 with 370 gears. i dont think its locking at all or the trans is not right. something is wrong

 

Sure sounds to me like the old setup was the not normal and the new setup is working the way it should. Most people rarely even aware of the Torque converter lockup. In my 2000 Z28 I only notice the lockup only when I am looking for it. After your post I watched mine. Its less then 100 RPMs.

When you see a large change RPM indicates a lot of slippage right before or after the clutch locks up. The pressures in your trans can tell the TCC to not engage but it will have no effect on the amount of slippage. The only way I know to "Fix" this is to find a worn out torque converter and install that. I am sure if you find someone with a worn out torque converter they will trade for the new tight one.

 

2000 rpms at 60 mph in overdrive should be around 370 gears in the rear, if its got 323s something is not right.

 

Again thanks for your reply. I think I understand but am I correct with the new trans the car is turning more RPM's at 60 or 70 so it will use more gas?

 

run through the gears to make sure its going into overdrive?

 

Yes, several times run through the gears to be sure all work including overdrive.