Anyone here running the Sonnex Powerglide Servos? If so which one and how do you like them.

yes ,have been using them for about 3-4 years now .. very nice suff . no issues ... this model ..Sonnax Powerglide Supported Servo 28821-20K

yes and the blue one is the one you want

quote:

Originally posted by rusty:
yes and the blue one is the one you want

Part number 28821-10K

If you have ever backed up when applying the trans brake, you need a 28821-10K kit

If you have ever pulled down your trans for a rebuild and the band has a burn mark down the center, then you need a 28821-10K kit

Honestly, it's the best money I have spent on my transmission, will NEVER build another trans without one.

Joe

I have a few of the 28821-20K in my cars.

I have the 28821-20K in mine but it's a stock case transmission with a bracket brake. If I had an aftermarket case and wanted the best I'd step up to a 28821-10K kit. Go to Sonnax's site and watch the video on the glide servo.

This message has been edited. Last edited by: Eman,

quote:

Originally posted by sr4440:

quote:

Originally posted by rusty:
yes and the blue one is the one you want

Part number 28821-10K

If you have ever backed up when applying the trans brake, you need a 28821-10K kit

If you have ever pulled down your trans for a rebuild and the band has a burn mark down the center, then you need a 28821-10K kit

Honestly, it's the best money I have spent on my transmission, will NEVER build another trans without one.

Joe

"If you have ever backed up when applying the trans brake, you need a 28821-10K kit"


Why?

I use the black cover -20K kit, I tried the blue cover 10K kit and burned up 2 bands in a row. Put the black cover servo back in and never looked back. Your results may vary

steve what is the difference in the 10 and the 20 i cant see any unless its the spring,,i havnt had any issues with the blue

quote:

Originally posted by rusty:
steve what is the difference in the 10 and the 20 i cant see any unless its the spring,,i havnt had any issues with the blue

Rusty, I am not saying there is anything wrong with the smart tech servo, I just did not have any luck with it

Blue cover -10
https://www.sonnax.com/parts/4...atio-style-servo-kit

Black cover -20
https://www.sonnax.com/parts/4...ted-servo-master-kit

just trying to see diff i had already read description and couldnt see it.maybe one is black and one is blue lol

quote:

Originally posted by rusty:
just trying to see diff i had already read description and couldnt see it.maybe one is black and one is blue lol

Rusty, I think they have different spring rates.

ok thanks

I believe the main differences is The blue one has a lighter spring and more hyd surface area behind the piston for release

The 28821-20K kit requires you to know what your line pressure is, in order to install the correct shims.

The 28821-10k has a 10% greater release area, the "stock design" servo has a 3% greater apply area (pin bias), which is why you need a heavy spring with the "stock" style servo, to keep from slightly applying the band (burned center stripe) as you go down track. The issue is when you are stageing at idle, you engage the transbrake and there is a momentary pressure drop as the reverse piston fills up, on some cars that "heavy" spring causes the band to release for an instant and the car to rock back. The 28821-10k uses a light spring because it uses it's 10% greater hydraulic surface area (release side) to keep the band from applying down track.

Steve, I have no clue as to why you had issues, the 28821-10k is designed to work with all pressures (self-adjusting). In the instructions, they warn about an issue with the pin-bore and seal-bore are not concentric. The interesting thing is that warning is not showed with any other servo.

Joe

link pin bias

I KNOW THIS WILL SOUND STRANGE....I HAD TO STOP USING THE GREEN SONNAX SERVO SPRING,,,IT WORKED TOO WELL ON THE SHIFT TO HIGH...IT RETRACKED THE BAND TOO FAST..

I SEEN THIS WITH A PRESSURE GAUGE ON THE SERVO....LETS SAY FIRST GEAR HAD 220-250 PSI..@ THE SHIFT TO HIGH GEAR THE GAUGE WOULD GO TO ZERO & COME BACK UP....THAT

TIME LAG BACK UP CAUSED HIGH GEAR TO SLIP...BURNED UP HIGH CLUTCH'S....I KNOW CERTAIN VALVEBODY'S ARE PRONE TO THIS ALSO...THE SONNAX STUFF IS FIRST CLASS STUFF..

WHEN I USE THEM...I SWITCH TO AN FTI OR HUGHES SERVO SPRING...JUST CHECK THE PRESSURE WITH A GAUGE TO SEE IT..SOME VALVEBODY'S ONLY DROP 50 PSI..AFTER I SWITCHED

SERVO SPRINGS..NO MORE HIGH GEAR DAMAGE HAPPENED...

quote:

Originally posted by sr4440:

Steve, I have no clue as to why you had issues, the 28821-10k is designed to work with all pressures (self-adjusting). In the instructions, they warn about an issue with the pin-bore and seal-bore are not concentric. The interesting thing is that warning is not showed with any other servo.

Joe

]

No idea either, all I know is I burned up 2 bands after installing it and problem went away after putting the black one back in, maybe the one I got was defective, I know lots of racers run that servo. This was on my TD and pressure in the 280psi range

Reading up on these servo kits it appears they only help/improve things when line pressures are over 200lbs......correct?
Also, it was mentioned earlier that this servo kit is a must if you use a button to back up.....why?
Finally, can this kit be installed without dropping the pan or even further disassembly?

Thanks,

quote:

Originally posted by imakehp:
Also, it was mentioned earlier that this servo kit is a must if you use a button to back up.....why?

The other post could have been worded more clearly. The meaning was "if you set the brake and your car rocks backward out of the beams."

I use and recommend the black cover on builds. Funny, The black with the heavy green spring will rock everytime when an abruzi valvebody is used. I have not had that issue with ANY other valvebody, it was ONLY the abruzi. Take and put the abruzi spring with the sonnax servo and it works great, and alot of times, you wont see the bands burned as often with those valvebodies.