So a few months ago we rebuilt our 727 and added a reverse manual valve body with low band apply along with a couple of billet parts.

We finally got her back together and fired her up. Park/Reverse/123 work great, but for some reason the tires spin forward in neutral.

We're wondering if this could be some kind of band adjustment or low fluid issue or if we have a bigger issue. We haven't ran the transmission other than on jack stands in the garage. So we don't think the clutches could be locked up. Though maybe we mis-measured some clearances somewhere.

We're looking for a little advice on where to look first. We read in the manual that it could be gearshift control linkage, but we are manually(with our hand) placing the selector valve into the gear we want. It also says it could be a malfunctioning or leaking VB. This is a brand new unit from CRT so I don't think that could be it, but is there a way to troubleshoot it to know for sure if we have to pull the tranny?

Thanks for any advice you can give it's appreciated!

That's normal...

Sorry... when you apply a bit of gas the tires will speed up. Meaning you can't stop the tires from moving if you tired with your foot once the car is running and they start to spin.

If applying the brakes stops the wheels from turning with no engine bog, all is well.

So let me get this straight. If the car is started and then put into neutral and the tires start to roll forward as if in gear. All is fine?

The only reason we even found the issue was we were trying to get the correct tranny fluid level so we were putting the car in neutral to do the check and found the wheels were moving while on jack stands so we are afraid something with the rebuild went wrong.

Yes entirely normal . Put it on the ground and see what happens.

Well I guess you learn something new every day... maybe even a couple things a day for us newbies. We will definitely try that today with hopes that the car won't end up in the living room and report back haha...

Thank you guys for your input. We were getting a bit down since we are getting really close to get the car back on the road after a year of downtime.

A BIG THANK YOU from the wife and I. We set her on the ground and gently let off the brakes and she didn't move. We gave her a little gas and still she didn't budge! We are super excited that so far so good! Just waiting/looking to find a swivel so we can actually move the gears around without crawling under the car and we may be able to drive it!


Thanks again!
-Luke and Lisa

It's like having 2 house fans facing each other & one is on & the other one is not on. the air from the one fan turns the other fan slightly, With the trans, fluid is slung from one set of clutches to the stationary set & you ain't aware of it normally cuz the car is rarely up on stands idling like you are doing. When you're up on stands BE SURE to stop the wheels with the brake pedal before shifting the trans to park or reverse. It's easy to space that off & I ain't did that gaffe but I've heard of it happening & it'll give you a very bad day

The effect is amplified with a higher than stock converter too.