The Dodge Challenger Message Board

This might be a completly stupid question but:
The slapstick of a 727 allows "manual" shifting. For racing, the standard valve body (is that the right term?) is often (always?) replaced with a manual valve body. So whats the difference between "manual" shifting with the slap stick and shifting with a manual valve body?

With a standard transmission you can shift down at any speed but the gear will not change until it is safe to do so. Also when shifting up early at full throttle the normal trans will still not shift up until the correct peak rpm (set by the kick-down linkage) is reached.

With a manual valve body you have to shift up and down manually all the time. The 'Drive' position is third gear only. But when you do shift the gears will change right then and not a few seconds later or when it thinks it is safe to do so. So you have total control over what rpm you can shift up and down.

My trans is modified a little to give firmer shifts but also I can change down at any rpm. It still shifts normally in drive. I do not see the point of a manual valve body on a street driven car. But maybe there is an advantage I don't know about?

Thanks Dave,
Your conclusion that there is no obvious advantage with a manual valve body on a street car is the same as mine and the reason for asking. Still you see quite a few of these around (at least in Sweden). Could it be that the max rpm for shifting with a max adjusted kick-down linkage is substantially lower than the max rpm you could squeese out of a slightly modified street car engine? I haven't dared trying at what high rpm you could have shifting with max adjusted kick-down. My car also have slightly modified firmer shifting.

Well a normal trans will still hold in gear up to any rpm so that is not the advantage. A manual valve body will allow you to shift early at wide open throttle. Also it will not shift down when in drive. Maybe that is an advantage but I don't see how.

Hi Guys!
I use a manual valve body in my Dart. One advantage is that you can do away with the kickdown linkage. As you say you have total control of when the box changes up and down,and also the shifts are harder than you get by installing a shift kit.For this reason i would think twice before putting one in a car that see's a lot of street use because all that thumping into gear must seriously shorten the life of your transmission seals & u.j's. I'm fairly sure that the box runs at full line pressure all the time (again,not good for longevity).I was under the impression that even if you held an autobox in a gear, it would still change up at whatever R.P.M the factory set the governer at,if that is the case then going "manual"would allow you to pull more R.P.M through the gears.As a reformed 4 speed man i just love being in control of a violent gear change! Oh,and of course manual valve bodys have a reverse shift pattern (PRN123) so you shift away from park , reverse & neutral ( hitting reverse at 6500 when you were aiming for third can seriously ruin your day!

Just for the record Blue, I have a standard 727 and SlapStick in my Challenger and when manualy changing up, the gear IS held until you shift again. i.e it doesn't change up at a pre-determined RPM. For that reason I couldn't see any advantage in changing the shifter in my "street" Challenger for the "Sportsman" strip use it gets. Cheers!

unless of course you buy a new valve body from Protrans that has TWO neutral positions John!
And trust me you have NEVER experienced an auto gear change like these guys build them to do, ouch.
Their valve bodies get around all the hesitating and lazy 2-3 shift of the Turbo action units.
The shifts in tweety are dramatic to say the very least and as soon as I get half a day spare I shall be down the barn and fitting my new billet all front drum to add some safety to the system, I don't fancy bits of the steel one coming out through the floor!
Martin as previously discussed, l'd be tempted to leave the car alone until you add some power,I'm pretty sure that it'll work just fine as it is with a bit of nitrous. Then when you want to step up to a new tranny talk to Blue he's the man for all that stuff, good luck mate

Cheers Andy, that's just what I intend to do, I'll keep you posted.

I agree with Dave. Unless you like manual shifting your transmission (why not have a 4 speed then) or you're doing a lot of racing, a manual valve body can be no fun for normal daily driving. A good valve body improver kit installed by someone who understands how the TF transmission works, can be made to shift just as hard as a manual valve body equipped trans. As Blue mentioned, too much line pressure can be the cause of premature transmission failure as well other driveline problems. I can't see one being of much value (other than feeding ones' ego ) on a vehicle that mainly sees street use.

The world of torqueflites has moved on a lot since the Turbo Action and B+M days guys, believe me!
Although in Martin's case leaving it stock is definitley the way to go for now.
My advice would be to simply buy a whole new unit when he's ready for the upgrade, $1250 buys you a fully sorted trans' sure it doesn't have all the billet stuff in there, but it'll be plenty for most peoples use

More than most people need I would have said. Why pay $1250 when for a few hundred you can re-build it yourself in a weekend and have lots of fun doing it.

Hum, then re-build it, then rebuild, then rebuild it......
Through a decade of doing this stuff and more 727's than I care to think about I have to tell you if only I knew then what I know now?