Help me ID this numberless servo.....

[Blazer406]

I might have jumped the gun..... all the searching came up short on the dimensions I am measuring on this used servo I got. It has a cover outside diameter of about (I measured with a scale... not calipers) 81mm or 3.189". The inside bore of the cover is just a shade under 2" in diameter.

So..... what did I get?

I can get pics if you like..... or more accurate measurements.

I was originally told it was an early 200 servo, but that he got it from a board member here. He never used it and decided to sell it......

 

[77 cruiser]

If it's only 2" it's not any good for perf. usage.

 

[Firechicken]

Is there a number on the inside piston? If so, what is it?

 

[Blazer406]

Is there a number on the inside piston? If so, what is it?

I don't see any numbers.......anywhere.....

 

[Firechicken]

There is a very old thread somewhere in the archives of this site which did discuss servo diameters and such. I will see if I can dig it up. I remember reading it a while ago, but I can't remember specifics.

 

[Blazer406]

There is a very old thread somewhere in the archives of this site which did discuss servo diameters and such. I will see if I can dig it up. I remember reading it a while ago, but I can't remember specifics.

Do you mean this one?

Linky

I read it..... saw no mention of a 2" piston.... I saw someting about 2.9 something ..... thought mine might be that one if the 2.9 something was square inches.... of apply area..... but it appears that they were referring to diameter... not area.... mine is about 2.9 sq in.....


Looks like I am out of luck.

 

[Blazer406]

I think I made a oops....

I think the servo has another piston..... I re-examined the correspondance between me and the seller.... and it appears that when I looked at it today.... I didn't fully disassemble the servo.... I saw the small piston.... just under 2" dia.... and the cover..... I didn't realize there was another piston made into the cover..... I should have looked more closely....... Seller says it has LESTER4 on the cover.... I guess that is what is on the underside of the piston I didn't see. I left it at work... so I will check.... and update the thread..... still curious if this is the one I was hunting.....

The seller sent this in an email:

In both the pics, the left side is the factory GN servo. On the right is the larger servo. I can't find any part numbers on the cover but the large piston has LESTER4 on it. It's about 1/2 larger than the factory servo and I was told this is the largest of the factory servos.


pic 1

pic2

The servo I bought is on the right..... the one with 3 pistons......

I was giving you guys the measurement of the little piston (3rd piston)

Does this make more sense?

 

[Firechicken]

Yes that is the thread I was speaking of. If you measure the large piston, you will have an idea of what the servo is when you compare with sizes mentioned in that thread.

As far as I know, the old 200 servos did not have the small piston. That only came later. I have both of the old 200 servos, the 133 cover and the 134 cover, and neither have the small piston. As well, the covers on my old 200 servos do not have a flat area on the outside center of the cover. They are both concave in the center.

 

[Blazer406]

Well..... according to my scale..... it is 75mm which is 2.95"

The piston has LESTER4 and also the numbers 863354 on it.....

I'll get some calipers......and re-measure........ looks like 2.95" OD on the piston.


Hopefully someone will shed some light on what I actually have......

 

[Blazer406]

TTT ..... nobody's seen one of these servos..???.. like in the pic I posted? ... with the three pistons......?

 

[Blazer406]

Bump.... Chris...? .... Brian......?

I hate to try and install it if I don't know if it will work like I want it to.....

stock one is on the left.... the one in question is on the right.......

 

[KEhrhardt]

Well..... according to my scale..... it is 75mm which is 2.95"

The piston has LESTER4 and also the numbers 863354 on it.....

I'll get some calipers......and re-measure........ looks like 2.95" OD on the piston.


Hopefully someone will shed some light on what I actually have......

Hrmm... you missing a digit on that piston? Usually GM part numbers are 7 digits. Maybe that guy LESTER would know?

 

[Blazer406]

Hrmm... you missing a digit on that piston? Usually GM part numbers are 7 digits. Maybe that guy LESTER would know?

The missing number could be on that casting tit that is on it.... it is right in the middle of the string of numbers......

I hate it when tits get in the way! That rarely happens. :biggrin:

 

[blackplague]

That numberless servo is a

Case Stretcher from a member of this board named brian. Install it, you'll love it. :biggrin:

 

[HellOnWheels]

Well..... according to my scale..... it is 75mm which is 2.95"

The piston has LESTER4 and also the numbers 863354 on it.....

I'll get some calipers......and re-measure........ looks like 2.95" OD on the piston.


Hopefully someone will shed some light on what I actually have......

Measured mine and it measures 2.975" ID for the cover, with Lester 8 on it (GM#8630569). The outer piston measures 2.970" with Lester 1 on it (also GM#8633564), and the inner measures 1.931".

So can anyone ID as to which servo I have?

 

[chris718]

its a modified stocker.bruce toelle sent me one a while back to examine.it is from mike kurtz originally

 

[KEhrhardt]

Measured mine and it measures 2.975" ID for the cover, with Lester 8 on it (GM#8630569). The outer piston measures 2.970" with Lester 1 on it (also GM#8633564), and the inner measures 1.931".

So can anyone ID as to which servo I have?

HOW,

The 569 cover/564 pistons I have seen have a smaller piston like 2.35" OD. I have one that I removed from an 85 Monte SS with the same GM part numbers you list, but with the 2.35" piston OD. I am surprised that you got a 2.970" OD on the outer piston. You sure on that measurement? Piston envy

 

[HellOnWheels]

HOW,

The 569 cover/564 pistons I have seen have a smaller piston like 2.35" OD. I have one that I removed from an 85 Monte SS with the same GM part numbers you list, but with the 2.35" piston OD. I am surprised that you got a 2.970" OD on the outer piston. You sure on that measurement? Piston envy

Re-measured: 2.977" id cover (569), 2.966" od outer piston (564), don't know why the difference except maybe temperature, measured with an adjusted dial caliper.


HOW

 

[brian]

Blazer406,
That is one of my servos.
Somehow... I overlooked this thread.
As Blackplague stated, put it in, you will love it!
Yours is the average size we use. I have one that specs out just under 3.25 in my Malibu now. It is a freakin` monster! It would be a bit much if it was not for my 3800 stall converter.
Brian

 

[KEhrhardt]

Blazer406,
That is one of my servos.
Somehow... I overlooked this thread.
As Blackplague stated, put it in, you will love it!
Yours is the average size we use. I have one that specs out just under 3.25 in my Malibu now. It is a freakin` monster! It would be a bit much if it was not for my 3800 stall converter.
Brian

So then are you modifying a stock piston to increase its surface area? I doubt GM would have two different diameter servo pistons with the same part number on them. Time to break out the alumalloy, a bottle of mapp gas and fire up the Bridgeport!!