slipping and shuddering from a stop????


Apr 8, 2005
Big car show tomorrow and trans decides to act up. Seems to be slipping and shuddering when starting from a stop, BUT not all the time. I noticed when I put it in drive, it didn't feel to 'positively engage'. Usually it will start rolling from idle, but now engine rev's and it barely moves like it's slipping, then if I give it more gas it feels like it fights back and shudders. Once it gets to 2nd it drives fine. Doesn't matter what position the shifter is in, behaves the same. Coming to a stop, it down-shifts from 3rd to 2nd, then to 1st. Fluid is full and looks great, may have a slight burnt smell (trying to pretend nothing is wrong...). Trans has been working great all summer, after putting in CK shift kit and billet front drum end of last summer. Trans already had performance clutches and servo. Firm shifts (chirps going to 2nd) and great response with CZ valvebody and governor front Monte SS. Pro Torque Non-lock up 2800 stall converter behind a Pontiac 400. I have not taken pressure readings yet. I checked pressures after the shift kit was in, and everything was fine.
Any ideas would be greatly appreciated. Thanks.
pressure readings

I took the pressure readings, with the trans cold.
Gear @MinTV @MaxTV
P 75 200
R 115 225
N 75 200
D4 75 200
D3 75 200
D2 210 215
D1 210 215

Are these pressures acceptable? Should they be higher? How?
I did not drive the car, but it felt like it engaged ok. The trans did not slip in first with my foot on the brake.
After measuring the psi at Max TV, there was a groan coming from the trans while in park.

I assume the forward clutch assembly is ok for now, but the pressure must have been low for it to slip in first.
Is the pump on it's way out?

I suppose I should drop the pan and look for metal, but I get the feeling the trans will have to come out for inspection.
Anything I'm missing?
What happens when you start off in manual LO? Lo roller clutch perhaps.
Thanks for the response. It did not seem to matter what position the gear selector was in. It would slip in first, then be fine in 2nd, 3rd and 4th. Would the Lo roller clutch slip then work again?
Can anyone tell me if the pressures are acceptable, or should they be higher? I don’t think the pressures have changed since I put the CK kit in, and it has been working great. Is the groaning sound likely coming from the pump? Should I drive the car and see if it slips again, then record the pressure or any fluctuation? Or should I just pull the trans? I don’t want to do too much damage if there is something I can fix before catastrophic failure. Thanks.
The pressures are a little low, if you have CK's PR setup you should have
90 min.& 230-240 max. I think. But they are not low enough to cause slipping. IMO