new trans problem

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R

rcottick

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Need ideas on what may have happened here. As you all heard about my cam troubles I went ahead and installed my solid back in it for now. So I get her all buttoned back together and running and I decide to go get fuel. Now this is a brand new trans (727) I had built with a greiner reverse manual valve body and a brand new ptc 9 1/2 convertor. Made sure it was all topped off with fluid. Filled it in neutral and then cycled it thru the gears and rechecked. Levels all good. Pull it out of the driveway and it has to rev fairly high to get her going, I'm assuming its the 3600 stall on the vert. start out down the block and all feels good. Give it a slight....very slight goose it it jumps to life....all smiles....just coasting now....give her a little more gas and...nothing....no 1st....no 2nd....no 3rd....after I come to a stop....no reverse either. CRAP SONZABICH GRRRRRRRRRRRRRRRRRR. The linkage seems to be moving it thru all the gears but its not going into gear at all. Any ideas? I'm really very frustrated and down. Its been one problem after another. I hope this is something simple that doesnt mean removing the trans.

Ron
 
rcottick said:
Need ideas on what may have happened here. As you all heard about my cam troubles I went ahead and installed my solid back in it for now. So I get her all buttoned back together and running and I decide to go get fuel. Now this is a brand new trans (727) I had built with a greiner reverse manual valve body and a brand new ptc 9 1/2 convertor. Made sure it was all topped off with fluid. Filled it in neutral and then cycled it thru the gears and rechecked. Levels all good. Pull it out of the driveway and it has to rev fairly high to get her going, I'm assuming its the 3600 stall on the vert. start out down the block and all feels good. Give it a slight....very slight goose it it jumps to life....all smiles....just coasting now....give her a little more gas and...nothing....no 1st....no 2nd....no 3rd....after I come to a stop....no reverse either. CRAP SONZABICH GRRRRRRRRRRRRRRRRRR. The linkage seems to be moving it thru all the gears but its not going into gear at all. Any ideas? I'm really very frustrated and down. Its been one problem after another. I hope this is something simple that doesnt mean removing the trans.

Ron
Click to expand...

Check the low/reverse piston, sound like it is leaking, bad seal, broken piston? Easy fix can be done in car. Unless somewhere else you have an internal leak?
 
Try pulling the v/body and air check all system's and possible front gasket between pump body to case blown. Check for possible valve body screw up, it could be dumping all hydraulic pressure's.
 
man is that line pressure port a ***** to get to. Anyways, I hooked the pressure gauge up and started the car, shifted it into all positions and reved it up, 0 psi the gauge didnt even move. I didnt have the fitting very tight because with the headers and everything in the way its a pain to get to so I was expecting a massive spray of fluid and got nothing zip nodda not even a drip. only fluid to get anywhere was the fluid coming out when the fitting was removed. So It looks the the pump took a dump. Out it comes and back to the trans guy. GRRRRRRR

Ron
 
It's extremely rare for a pump to take a dump like that and there are other things that can cause no pressure. I'd suspect it to be a valve body problem or blown seal (most likely from improper installation) rather than the pump but a pump is possible. Which port were you hooked up to? The line pressure port is on the passenger side approx. in the middle between the 2 humps for the servos.

Here's a pic out of the FSM that shows what ports are what.

727 pressure test ports 2.jpg
 
More than likely the lugs on the inner pump gear broke off. Instead of replacing the whole pump, you're better off buying a hardened pump gear set for your existing pump. That way you don't install another pump with the OEM pump gears and have them break again.
727_build_024.jpg
 
Duster346 said:
More than likely the lugs on the inner pump gear broke off. Instead of replacing the whole pump, you're better off buying a hardened pump gear set for your existing pump. That way you don't install another pump with the OEM pump gears and have them break again.
727_build_024.jpg
Click to expand...

Duster436 beat me to it, My money is the engagement ears on the front pump inner gear have sheared off. This is prone to happen when you let off the throttle or engine kicks back. Replace them with a heavy duty set like A-1 transmission make.
 
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