In the past, I have used the dual ring or the Sonnex upgrade, which supports the servo pin at the cover.
I think the Sonnex upgrade may be unnecessary for 575 - 600 horsepower range.
Let me hear from those of you who build Powerglides for the milder engines. What do you use for the servo?
Larry Woodfin
April 13, 2025, 04:29 PM
rusty
8821-10k is the one we use
honesty is the best policy,insanity is a better deffense 1.036, 6.16@ 224
April 13, 2025, 06:51 PM
SP 124X
We have a few stock cover/dual ring servo and a few sonnax 28821-20K setups.
Denis LeBlanc
April 14, 2025, 07:51 AM
sr4440
quote:
Originally posted by rusty: 8821-10k is the one we use
Ditto, fixes so many issues.
Without data, you’re just another guy with an opinion.
April 14, 2025, 03:18 PM
329L
The sonnax 28821-20k is the one i prefer.
Jeremiah Hall
April 14, 2025, 04:25 PM
Larry Woodfin
Because of the relatively low power level I am talking about, I agree that the #20K is suitable.
I also agree that with Rusty's power level, he needs every trick possible.
My old home built small blocks do not require many extras. I even reuse most of the gaskets
Larry Woodfin
April 14, 2025, 04:31 PM
rusty
servos require matching the servo spring to the pressure being used.i have been on the phone today with 5 different experts and companies to sorting issues.as one siad the most simple trans out there can cause the most issues
honesty is the best policy,insanity is a better deffense 1.036, 6.16@ 224
April 14, 2025, 06:10 PM
moparacer
I run the 20K.225PSI. Not high power. 850hp. Stock case.
April 14, 2025, 09:05 PM
Hutch
28821-20k is a nice upgrade to any powerglide build regardless of power.
Originally posted by rusty: servos require matching the servo spring to the pressure being used.i have been on the phone today with 5 different experts and companies to sorting issues.as one siad the most simple trans out there can cause the most issues
FYI the 28821-10k Eliminates the need to calibrate servo return spring to line pressure or varying case depth. According to sonnax, it's an upgrade from the 28821-20k.
Without data, you’re just another guy with an opinion.
April 14, 2025, 10:36 PM
Big Steve
For what its worth when I had the TD I switched from the 20K to the smart tech 10K and burned up 2 bands, switched back to the 20K and never burned up another. I never determined what was wrong that caused the bands to burn, was just happy it was fixed when I switched back
April 16, 2025, 08:58 AM
329L
quote:
Originally posted by Big Steve: For what its worth when I had the TD I switched from the 20K to the smart tech 10K and burned up 2 bands, switched back to the 20K and never burned up another. I never determined what was wrong that caused the bands to burn, was just happy it was fixed when I switched back
^^This is why i use the 20k. Only issue i ever had was trying to use the heavy green servo spring with Abruzi valvebodies. Change it back to the Abruzi servo spring and works fine. The actual issue was when you activated the transbrake, it would rock really hard.This message has been edited. Last edited by: 329L,
Jeremiah Hall
April 18, 2025, 02:33 PM
Hutch
The green spring is not heavy. By putting in a weak spring that is completely defeating the purpose of the servo system you bought.
quote: Originally posted by rusty: servos require matching the servo spring to the pressure being used.i have been on the phone today with 5 different experts and companies to sorting issues.as one siad the most simple trans out there can cause the most issues
FYI the 28821-10k Eliminates the need to calibrate servo return spring to line pressure or varying case depth. According to sonnax, it's an upgrade from the 28821-20k.
htt
the 10 is the one they told me to run
honesty is the best policy,insanity is a better deffense 1.036, 6.16@ 224
April 19, 2025, 12:23 PM
Alaskaracer
My buddy Danny runs the 10k in his funny car and has had zero issues with it. I was running the 20k in my car and also zero issues. I went with the 10k for my new trans to see how things go...Hopefully they go well, I've already found an issue I need to fix, but it will have to wait until I pull converter to change stators again.
Mark Goulette Owner/Driver of the Livin' The Dream Racing dragster www.livinthedreamracing.com "Speed kills but it's better than going slow!" Authorized Amsoil Retailer
