hhi

can a 1973 vb be used in a 1969 /1970 to get ptkd

thank you !

Mopar change the 727 in 1971, they converted them to light part throttle down shifting from 3rd into 2nd below 25 or 30 MPH, they stayed in 2nd gear longer also
I have no idea what that involved in those trannies

I believe you can just move the PTK assembly to the other VB , but yes you can also swap over the VB .

The big change in '71 was in the area of the accumulator, swapping the '71-later VB into a pre-'71 eliminates part of the accumulator's function...it'll work but it would be better to just swap the PTK module onto the early VB as JohnRR suggested..

What is a "PTK"?

Part throttle kick down?

🎯👍

Thanks

I thought the later ptkd wont fit the early vb? You’d need an early 6 cly one to fit the early trans? A and A sells the early version.

http://www.aandatrans.com/Products/727-3-2-Kick-Down-Module-(1966-69)__22740-32SI.aspx

Here it is. Says you can’t switch between styles

I’ve never done the late to early module swap myself but a google search suggests it’s a common swap with the only issue being clearance with one of the separator plate screws. A button head screw appears to solve that problem.

John could you go into more detail on the change in the accumulator function?
Doug

On the pre-'71 the accumulator piston has fluid pressure bearing on only two surfaces. In '71 they added the 1-2 Shift Control Valve which sends fluid pressure to a third surface of the piston. Basically, the early accumulator would cushion the 1-2 upshift the same at all throttle settings where the later cushions the 1-2 upshift depending on the throttle setting.

To make this change, they added another fluid passage to the case, so when swapping VB's, all the fluid ports don't line up correctly.

The difference in the PTK modules is the addition of a limit valve in the later module that limits PTK to about 40 mph and below. With the early module it would still kickdown at higher speeds depending on the axle ratio.