Took the car out for a spin with the new 383, seemed like the tranny was slipping a little, got 20 yards up the road and it felt like the engine was free revving. Nothing, no reverse, no drive on any gear. Fluid level looks good & color is fine (only has about 1/2 a mile on it).

I should mention that when bolting up the tranny to the new engine, in my haste I had messed up the pump because I missed the last "click" when putting the converter on, and it put pressure on it. The pump was replaced, and I drove the car around the block once and it felt like there was a little slipping, but the car still moved.

I know it could be so many things, but the tranny was working fine before my mishap. Any ideas? Suggestions on things to check before pulling the tranny? Things to check after pulling it? If the pumped wasn't working, I assume this is how the car would react? Does DataMaster have any useful info for diagnosing? Easy way to check if there is fluid pressure (don't have a gauge)?

Thanks!

 

to check that the pump is working easily remove a line at the radiator have a freind start the car for just a moment it should squirt fluild , if it dosent the pump is dead

 

Thanks for the input! I was able to track down a 200 psi gauge last night so I should be able to check the actual pressure.

Transmissions are like brain surgery to me - I could cut the head open and that's about it. Crossing my fingers that it's the pump.

 

...Sounds like the pump. You're pointed in the right direction by checking your pressure. Was the hub on the converter OK when you replaced the pump? We've seen repeated pump failures after a converter misinstallation because of damaged converter hubs. Sometimes you won't even be able to see the damage. The hub should be checked for "run out".

Frank
CPT

 

Got hold of a gauge and there's zero line pressure.

Am I checking the OD or the ID of the hub for runout? I have a dial indicator, but I'm not positive how I would set it up and spin the converter. Probabaly better taking it somehwere. Too bad I'm not closer to Delaware!

 

It should be chucked in a lathe to check for run out. They'll be checking the outside of the hub. This is what centers your pump rotor.
Other areas to look for:

Are both dowl pins sticking out of the back of your block far enough? The trans has to center on those dowls to keep the same cenerline between the crankshaft and converter. If your dowls are in the block too far (or missing) it'll cause an alignment problem. We've seen people leave them out after a motor build.

Too much crankshft end play will cause repeated pump failure also.

How much converter gap do you have when the trans is bolted up? You should have between 1/8" and 1/4" between the flexplate and the converter lugs before pulling the converter forward.

Is your flexplate good? If a plate cracks, or dishes, it can cause a pump failure problem.

Frank
CPT

 

I'll have the converter checked. Pins are good. Gap looks good.

Flexplate could be an issue. It didn't want to go onto my new crank so I had to do some light grinding on it to get it to go on. Maybe it got off center from that a little?

Thank you for the ideas!

 

How much did you grind? This could certainly throw it off center.


Hey, we're here to help. Let me know what you come up with, or if I can help you any further.

Frank
CPT