[TheRktmn]

Can someone please explain the letter designators for C6 servos?
I have been told that the 3 best are D, H, R with R being the best for the strip.
I have an N in my C6 now and have the oppotunity to get a P, which I am told is better than my N, but isn't an N better than a D or H?

 

[Cougrrcj]

C-6 servos

Wow, you're asking me to wrack my brain of old info. That is not a good thing any more. My internal hard drive (brain or memory) is getting so old and full (I opt for the full : ) that I'm starting to overwrite what was there. You know, over write old seldom used files? ( Ba-dum-Dum ) Hey, if I have to explain the supposed joke, I guess it really isn't one. :1poke:

Anyway, back to the point of this post... C-6 servos. Ummmmmm. Gee. I'm gonna have to ask my tranny guy again when I see him tonite. I know it has something to do with how fast they apply due to different sizes/shapes. Like I said, I'll get back to you on this one. It has been too darned long since I have built up any C-6s.

Cougrrcj is having another 'senior moment'.

 

[Cougrrcj]

OK, I talked to my tranny guy, who also happens to work at a Ford dealership. The servo letters do not run in any sort of order. Yes, the 'R' servo is supposedly the best one, but those usually go for big bucks. My guy just went to a boneyard and took a look at thier tranny pile. He popped off the servo covers of all the C-6s he could find and took a look at them, taking the biggest for his race trans. He wasn't paying any attention to the relative sizes of the servo/pistons so I can't tell you what order they go in.

Not only do the servo/pistons vary, but there is a pivot lever inside of the trans that also makes a difference. On a C-4 the servo piston acts directly on the band, but the C-6 uses the lever. The servo piston acts on the middle of the lever, with one end of the lever pivoting on the case (fixed) and the other end pushes on the band. There must be a problem with those levers in racing use since they are known to break often if the pressure in the trans (and to the servo) is run too high. Someone makes a billet aluminum lever that is stronger than any of the factory pieces.

Hope this helps you somewhat.

 

[CougarAOD]

The N servo isn't that great, the S has more surface area and I think it is the L that is even better but the R is the best. Sonnax Trans Parts makes a really nice billet C-6 servo that is supposed to be even better then the R and is has sealing rings on the shaft and comes with tuning springs. You need the tuning spings to get he 2-3 shift timied right---timed as in the band release speed versus the direct clutch apply. If you have a 2-3 flare-up then you're return spring is too heavy, if you feel a bind on the 2-3 then your servo return spring is too light.
Most after market trans parts companies make a billet C-6 servo if you are unable to obtain one from Sonnax.

www.sonnax.com


hope this helps ya some,