PTS Adjustable Servo Pin question

[Brooks]

If you use the PTS adjustable servo pin, what's the proedure for measuring and adjusting band clearance?

Also, on the PTS website it says the adjustable servo pin eliminates the 2-3 accumulator piston.

Is this a requirement of the adjustable pin design (Looking at the diagrams in the ATSG manual I can't figure out how that would be) or is the remoal of the 2-3 accumulator a recommendation to get the best shift quality from the modified band clearance?

Transmission newbie,
Charles Brooks

 

[Brooks]

Has anyone used the PTS adjustable servo pin? If not the PTS setup, how do you guys go about measuring/adjusting the band without the "special" tool?


Charles Brooks

 

[77 cruiser]

I set mine so I couldn`t turn driveshaft backwards & then I removed 1 shim. You should have about .06 travel pushing in on the cover.

Jim

 

[88S10Durango]

Hi Jim ,, by .06 how much is that ? like in thousands would it be 60 thou ? Or like 1/8th of and inch , don`t understand what you meant about that ,,I`ve read alot of posts on driveshaft turning and the pushing in on the cover , and i understand those steps ,,

 

[Steve V]

I have this set up,Bruce has eliminated thr 2/3 accumator. The upshift is nice the downshift is clunky,I am considering putting the stock pin in with the big cushion spring. But keeping the servo,just the pin.

 

[77 cruiser]

.060 inch. actually I don't think it's that critical as long as it's not too tight.

 

[88S10Durango]

Thankyou for the reply ,thats like 1/16th of an inch , when I`m under mine again I`m going to push in that cover just to see how far it actually goes in ,I still have a stock servo in mine , Bill ( its the curiosity thing killing my mind ,, lol )

 

[jakeshoe]

.060" is a good target, can be a bit tighter too. Clearance has a big effect on 2-3 shift. Tight is good.

One thing,
you can't really check band clearance by depressing the cover.... Gotta have an extra cover with a hole in it.

ALWAYS leave the cushion spring in place on the servo.

 

[Steve V]

If 95% of the builders say never remove the big spring,why did PTS design their pin without it? Bruce...............?I know he has a great rep for strong 200's thats why I bought his 9/11 and servo/pin setup. There's no way to add the big spring with his pin,so going back to the stock setup is the only option.

I have CK's book and has alot of his mods in my trans and it works great with the exception of the 3-2 clunking(which is Bruce's). It's not as hard as the old super servo though.......

I guess guys with fast 200's don't care about the harsh downshift?

 

[jakeshoe]

Bruce's servo looks nice,

However leaving the cushion spring off the assembly is a bad idea. That is why Bruce also uses 300M band anchor pins....

The servo is a hydraulically applied device. It is a piston, in a cylinder (servo bore). When you apply it, there is NO cushion in the apply. Oil does not compress.
So when the band comes on, when it hits the end of it's travel, the only cushion to apply is that spring. Otherwise you are jerking the band anchors, anchor pin, and case.
You also get the 3-2 downshift clunk.

Also a little clue, most transmission hard parts failures happen on a downshift...

You can make these things shift brutally hard into 2nd AND 3rd on the upshift and still have that spring in place. And not have as harsh of a 3-2 downshift.

 

[Steve V]

Thanks Jakeshoe for the info! Bruce is a great guy but I think I will remove his pin and keep his servo setup!

 

[WE4]

Ck out this thread.

http://www.turbobuick.com/forums/transmission-talk/232340-adjusting-adjustable-servo-pin.html

Bruce
WE4
Performance Transmission Services

 

[charlie]

sonnax

We have installed the Sonnax Super Servo with great success. Minimal 3-2 downshift clunk and excellent instructions for setting the pin servo travel. Another option you may want to consider.