Building a unit for a guy. I’ve always just used a stock spring in the forward accumulator (the accumulator in the valve body) and the yahoo who built this thing before me did some fraggle naggle bullshit on this thing and broke like two coils off the spring and put a spacer on the backside of the piston. The broken (yea they didn’t cut it, they broke it so the thing was sharp) spring cut through the plastic piston and left a big hole in it. Could be why the forward clutches were smoked?

anyways, I’m in dire need of a spring and my parts place does not have one today. This unit has to go tonight. I put a sonnax pinless billet piston in it. What would it do if I either

1) put no spring? Shift too hard? Bump shift?
2) just found another similar spring and used that?

If anyone has the part number for that spring, maybe I can get one from the dealer. It’s like a flat or oval wire spring. Thx

 

use any other accumulator spring you want
lighter spring=softer apply

I actually block the fwd accum with a setscrew on a transbrake valve body i'm designing/testing and it isn't too aggressive.

p.s. no the valve body isn't done yet...but I can confidently say the fwd engagement isnt TOO bad with the fwd accum blocked. No worse than any th400 that is in a high performance car

 

thanks brochacho! I may be machining the pocket on the piston tonight lol

 

The Forward Accumulator is not really needed...
There are multiple ways to soften the Forward apply.

The early design for the forward clutch did not have a Forward Accumulator (Pre-1987 THM700-R4)...
It was added for the vehicles that have to keep Grandma happy with softer shifting.

Depending on the Torque-Converter used/ design/ stall-speed...
and orificing for the Forward Clutch; you really won't notice that there is no more Forward Accumulator.

 

I agree wholeheartedly with the post above

 

well unfortunately I don’t have time to figure all that out, trans has to go this evening. It’s a stock converter for now.

 

Use any spring that you have that will fit the piston properly and is not firmer than the original spring.

 

thanks...that was the plan. i'll probably have to chuck the piston up in the lathe, but it is what is is.

 

Vortec, can you go into a little more detail on this?

In my opinion, the more accumulators you can eliminate, the better.

 

Well to simplify this some...

Do you have any experience with Seporator-Plate Feed Orifice sizing after installing a new higher Stall-Speed Torque-Converter?
Often you would find that the Feed Orifice sizes will need to be increased (to maintain the prior shift feel/ firmness), as the new Torque-Converter will take more shock, and reduce the firmness/ Feel of the Shifts.