How do I know if my TC isn't stalling?


Supporting Member
May 26, 2001
I posted this message a couple of days ago, but deleted it after doing some work on the car. Here goes:

Been having trans trouble since November of last year. Something happened to it, still not really sure what. I pulled it out of park, it didn't want to go so I pulled harder. It clunked into reverse and stalled as if the engine was directly attached to the trans. Drove it around like this and it was terrible - stalling, surging, etc. Pump was making clicking noise.

Had a Red Stripe converter and hardened stator support from BGC installed. Didn't fix it.

Had an Art Carr rebuild kit installed, didn't fix it but the symptoms are different. I'll 'splain in a minute. Pump not clicking any more, now whining very slightly. Replaced pump with 10 vane pump. Still not right. Replaced governor, servo. Still the same….everything seems to be working, but it just doesn't feel right.

So here's the symptoms:

I'm thinking that somewhere along the line we actually solved the original problem, but the new Red Stripe converter is bad. Shifts are okay now (didn't have 2nd gear before - it went bye-bye just before the Art Carr kit), but it seems to be working very hard to get moving. Seems sluggish. Gas mileage is in the crapper. I KNOW it's sluggish because I drove my Typhoon to work today and it felt FAST. I'm thinking the converter is too tight. If I rev it up against the brake I can get it to stall, but if I floor it off the line it bogs pretty bad. Won't spin the tires until I'm moving pretty quick, and again on the 1-2. With the D5, I could just stomp on it and it would lurch forward and break the tires loose. It was pinging, too, which I thought was a symptom of the extra work it was doing, but it turned out to be the 25 psi I was hitting because of a split vacuum hose (oooops).

Here's another symptom that's hard to explain. In 4th, at a cruise speed and low RPM if I give it a little gas the RPMs will immediately pick up and then drop as if it shifted. It's not the TCC locking up (I just replaced the solenoid just in case, plus I know what that feels like), and I know it's not shifting. I'm thinking it's the converter reaching its stall speed. BUT, it's not like it's supposed to be. I used to be able to "rev it" sort of in any gear - as if it's in neutral - before the torque converter would catch and pull. Same in the 'Phoon - I can rev it up and feel the converter "catch". Now, it seems that during this time it takes to catch (below the stall RPM) it's bogging - it's never really completely free. I hope this makes sense…it just doesn't seem like it's stalling right.

I have another D5 to put in it, but I'm wondering if that's really the problem. Any ideas?


Lets try this again

Is there anything in the trans itself that would cause the car to be sluggish off the line and basically have no pull at lower RPMs? The turbo is spooling slower, too.

There's nothing mechanically wrong with the engine that would cause it to be down on power.

I'm thinking the TC isn't stalling. I'm going to replace my Red Stripe with a stocker this weekend unless someone can give a reason not to....(other than that with the PT51 I need higher stall - I know that, but I want to first figure this trans thing out).

Doesn't happen too often on these GM 12" units but it's possible that the roller clutch in the stator isn't holding properly. That would reduce torque multiplication, stall speed and act sluggish.
Woooo hoooooooo!

It was the torque converter. The car is completely back to normal now that I put the stock D5 back in. The Red Stripe is junk - it never worked right. Unfortunately, I don't know who made it.

It wasn't stalling. The car was really sluggish. That afraid-to-mash-the-pedal-for-fear-of-losing-the-back-end feeling is back. It was such a dog before!

Thanks to all who replied (here and privately).