47rh front clutch orfice restrictor

dotson90

dotson90

Chupacabra
Joined
Mar 24, 2011
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Looked around and couldn't find anything on this. Anyone familiar with doing this? Read about it in "Torqueflite A-727 Handbook" by Carl Munroe. Just wondered if this was necessary to do with my suncoast manual VB? Or does Suncoast block this somewhere in the valvebody? This is my first auto trans build, any help or tips would be appreciated.

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Just make an aluminum plug with 1/8 inch hole in it and fit it to the hole. Then you can fine tune it for shift quality as you want.

What you are doing is balancing the timing of front clutch apply with the release of the front band.
Also, there is a few things to be aware of.
Spring count in the front clutch, spring strength of the front servo, line pressure are a few of them.
 
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Thanks, I understand how to do it. Here's a little more info. I have the billet piece from DTT, it came with one more spring and is machined to accept 10 springs, which is what I'll be running. Just didn't know if anyone that installed a manual VB from suncoast, goerend, etc. themselves, had done this? Hadn't seen people talk about it.
 
With a 4.2 ratio lever, stock intermediate servo with sonnax o-ring sealed cover, stock 9 spring setup, stock apply piston, (2) added 1/8" feed holes, kevlar flex band, and (6) clutch flat retainer with .050" clearance, and 200-215 psi line pressure, my 47rh has perfect shift timing on the 2-3 shift with no modifications to the case whatsoever. Both the band and the direct clutch are wearing normally and holding up fine. I don't have a fancy accelerometer to check for bind-up but my seat of the pants meter feels crisp, firm shifts.

All that said, your results may vary!!!!!!

Most of the guys with bind-up issues are running upgraded aftermarket intermediate servos with better seals. These bigger servos are slower to release, compound that with an odd ball 4.4 or hemi 5.0 ratio lever and bind-up is real possibility.

I really like the 4.2 ratio lever with stock servo and upgraded cover. In my opinion, when line pressure starts hovering in the 200 psi range, there is no need for a larger servo and radical ratio lever, all that does is risk case breakage from too much force.
 
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dotson90 said:
View attachment 41685

Thanks, I understand how to do it. Here's a little more info. I have the billet piece from DTT, it came with one more spring and is machined to accept 10 springs, which is what I'll be running. Just didn't know if anyone that installed a manual VB from suncoast, goerend, etc. themselves, had done this? Hadn't seen people talk about it.
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That extra spring that the DTT kit includes is heavier than the stock spring as you will see and will aid in speeding up 3rd gear release (direct). If you use their rebuilt kit, it will also include a heavier spring for the front servo to control 2-3 shift and any potential bind up

There are also centripetal forces at work with spring loaded drums but that is a different subject.
 
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