Engine/Transmission (1994 - 1998) Convertor lock-up or overdrive ?

[TEasley]

When my transmission upshifts even under light throttle it just stays around 2000 rpm with almost imperceptible shift points, then the last shift, at around 50 mph drops rpm about 350-400 rpm and kind of mushes in. Is that convertor lock-up or overdrive or both? I always have OD engaged. Convertor and transmission are stock.



Whichever one it is, is there some way to make it happen at a higher speed ?



Thanks, Tom

 

[Ruckuz]

I'd guess TC, but someone else will be able to tell you for sure. i have a shift kit, TC and stock transmission. Mine shifts real hard... you can count shifts without a doubt. When my TC locks up, the rpm's drop about the same as yours do, and it pulls like a rocket.

 

[bdcraig]

My 95' did the same till I stuck a torque plate in it. It now locks up at around 60-62 Mph and has plenty of power to go with it then. Before when it locked up it wouldn't unlock even with the pedel mashed to the floor and it didn't have a lick of power. Very slow getting into traffic on the interstate. With the plate it will unlock the TC when I mash it to the floor. Don't know what the plate changed on the shift points but I like it a lot better.



Brian

 

[Howard Durand]

The shift into OD is usually positive enough that you know it. The shift you are referring to is TC lockup.

Once TC locks, if you have good engine power, you should be able to accelerate to freeway speed quite rapidly.

The kickdown feature is not intended to serve as a passing gear. It is handy when pulling a load and need to downshift.

 

[TEasley]

Howard, does removing the tps raise the lock-up and/or OD shift point ?



Thanks to all, Tom

 

[Howard Durand]

I don't know if it will even shift into OD without a signal voltage. I have removed the TPS on my truck and replaced it with a potentiomter which provides a manually adjustable signal voltage.

The combination I am using allows me to vary the signal from 0. 8 volts to 2. 5 volts. At 1. 0 volts it shifts into OD at 32 mph and the TC locks up at 44 mph.

On the other end, at 2. 5 volts, OD shifts at 47 mph and TC locks up at

51 mph. I think raising the voltage more will result in an even later OD shift.

 

[TEasley]

Thanks Howard. I'm going to be off line for a few days, but will follow up on the potentiometer when I get back.



Tom

 

[Mbschmidt]

i just got a 96 & experienced the exact same shift patterns as you describe, except for when my converter would lock up there was a very noticable clunk, then i could feel it locked up. The lock-up was a bit unsettling though, as I felt the clunk was a bit excessive. I was told that a product called shudder guard would help so I added a container to the transmission & now the lock-up is super smooth, but still feels good and solid-no slip. I wonder if anybody else has had this experience & how they have dealt with it.