Manual Valve Body and street driving

[Carl Wiese]

So......hypothetically if someone had a 727 with an art carr full manual reverse pattern valve body, would there be any adverse damage done to the transmission if it were driven on the street from time to time? Like on a weekend, or for short trips? The trans also had a bolt in sprag and a 5.0:1 second gear engagement lever.

 

[Robert Kenney]

No not at all. The manual valve bodies are intended to make gear changes @ full throttle so around town will impart only easy shifts in relative terms. Make sure the control pressures keep up with the torque output(throttle position) of the engine. The worst possible senerio is overly soft shifts.

Your question is fairly vague actualy. Is everything in proper working order? Hook a pressore gauge to the controle pressure port and make some pressure checks. See if they corralate to book suggestions vs manifold pressures.

 

[Michael Mayben]

Ditto Robert's reply! Is the throttle pressure control on that unit still functional? I'd have to research exactly "how" the valve bodies are modded by the carr operation to handle line pressure regulation. Otherwise, as Robert says, at light throttle application, the manual shift May be so soft that flare will be experienced which means that the clutches and bands are are gonna experience elevated temps!

The bolt-in sprag (overrunning clutch race) is done as a repair scenario in order to salvage a damaged tranny case, too many folks add those thinking they add some strength. In the case of pushing 600>800 hp through a 727, that might be valid... But the primary reason we install bolt-in overrunning clutch races is to salvage a case that has experienced a spun race.

The increase in band apply lever ratio only increases the clamping force of the band, has nothing to do with shift timing.

 

[Carl Wiese]

The transmission is in fine working order, I just want to keep it that way. As far as throttle pressure goes, the art carr has none. There is way to attach the throttle pressure lever to the valve body, it was the reason we bought it as it didn't use any sort of throttle pressure regulation.

I am considering a build using this transmission in a occasionally street driven rig and just wanted to know if I should figure in a valve body swap.

Fyi this is the valve body we are using art carr off road rpfmvb, it says compression braking in all 3 gears, and I confirmed it with them before I bought it, but it's never worked in first.