tranny pressures - what to look for?

Posted By: boscosis

tranny pressures - what to look for? - 08/28/11 01:23 PM

We've got a fresh race tranny with problems - it acts like it's in two gears at once. It has an older A&A non LBA reverse manual valvebody if that matters. This my first time to check pressures. Can someone give me a quick rundown on how to do it and what to look for please?

Thanks

Posted By: mopar400

Re: tranny pressures - what to look for? - 08/28/11 01:45 PM

Posted By: boscosis

Re: tranny pressures - what to look for? - 08/28/11 02:31 PM

I've got Carl Munroe's book for reference I just hoped that someone could tell me what to expect if something is wrong.

Thanks

Posted By: 440Jim

Re: tranny pressures - what to look for? - 08/28/11 02:58 PM

Quote:

I've got Carl Munroe's book for reference I just hoped that someone could tell me what to expect if something is wrong.

Thanks

Carl's book has some good instructions and pictures of the pressure measurement points, pages 207-209. The only thing I will add is that with your manual valve body, the line pressure at 1000-1500 rpm should be at least 120 psi (90 psi stock), and depending on the design it could be 140 or more.

I think if the pressure is low it is likely a ring/seal issue, or if basically zero pressure the pump drive tangs could be broke off.

The feeling of two gears at once is tough. While you are testing with the trans in the car, the simple things like shifter cable adjustment are worth doing. Even disconnecting the shifter cable and putting the lever in each gear by hand and then checking how it moves the car.

Posted By: rickraw

Re: tranny pressures - what to look for? - 08/28/11 04:40 PM

need more specifics. if were in 2 gears it won't move. i agree with 440jim, check ur cable for detent. ur trunion should lift out of the selector arm with no pressure on it, meaning u have perfect gear selecting. line pressure is checked on the center 1/8 pipe plug. i have 180#-1st, 160#-2nd&3rd. if u don't get a reading on the center plug, u will have to hookup 2 quages, 1 on the front plug & on the rear of the case. stay safe, seeya.

Posted By: John_Kunkel

Re: tranny pressures - what to look for? - 08/28/11 08:55 PM

The OP needs to explain why he thinks it's in two gears at once....the problem might not be pressure related.