Rough 2-3 detent with dual feed?

[77 cruiser]

Is that the nature of it? I didn't do the 3-2 valve mod when I did I just used CK's plate.

 

[mikestertwo]

Are you talking the 2-3 up shift or the 3-2 down shift?

 

[77 cruiser]

OOPS! Yea the 3-2 down shift, slap me.

 

[mikestertwo]

A rough 3-2 down shift is usually caused by a missing cushion spring in the intermediate servo. Dual feeding should have nothing to do with it.

 

[77 cruiser]

It has the cushion spring.

 

[Ttype6]

It has the cushion spring.

Are you talking the big spring or the little one. The little one that slips over the tip of the servo is the return spring. The cushion spring is the big one.

 

[77 cruiser]

Big cushion spring, my servo doesn't have a return spring. It's the big one from a 200C.

 

[Ttype6]

Big cushion spring, my servo doesn't have a return spring. It's the big one from a 200C.

You need to have,at least,a GN return spring.

 

[mikestertwo]

It's the big one from a 200C.

That's your problem. When you use that servo the downshifts will be abusive.

 

[77 cruiser]

It was good before I duel fed & used the other plate.

 

[mikestertwo]

It was good before I duel fed & used the other plate.

The feed holes in the new plate are bigger than stock which is typical. Combined with the 200C servo it is abusive. If you can live with it that's ok. If not the prudent thing to do is put a GN servo in. The point is it's not the dual feed that is causing the issue.

 

[77 cruiser]

Does every one the uses a big servo have the problem?

 

[mikestertwo]

Does every one the uses a big servo have the problem?

It depends on what mods are done and which large servo you are using. If you use a stock spacer plate the issue will be reduced. I removed a 200C servo from a customer's car because he didn't like the feel of the down shift. I installed the large Superior servo with the cushion spring and CK's heavy return spring and he was happy. Still had firm upshifts and a much more mild down shift.

 

[RmvBfrFlght]

It depends on what mods are done and which large servo you are using. If you use a stock spacer plate the issue will be reduced. I removed a 200C servo from a customer's car because he didn't like the feel of the down shift. I installed the large Superior servo with the cushion spring and CK's heavy return spring and he was happy. Still had firm upshifts and a much more mild down shift.

I had the same brutal 3-2 shift with just the Superior servo. It was binding up as it was in 3rd & 2nd both for an instant, rattled the drive-train something fierce. I added the CK return spring and a stock cushion spring setup. Shifts great now. Note that the brutal 3-2 shift would also occur when slowing down to a stop.

From reading here (and elsewhere) when dual feeding isn't the 3-2 valve supposed to be blocked forward? Would this have anything to do with the harsh 3-2 shift? I don't know enough about the function of the 3-2 valve to know.

RemoveBeforeFlight

 

[77 cruiser]

I had the same brutal 3-2 shift with just the Superior servo. It was binding up as it was in 3rd & 2nd both for an instant, rattled the drive-train something fierce. I added the CK return spring and a stock cushion spring setup. Shifts great now. Note that the brutal 3-2 shift would also occur when slowing down to a stop.

From reading here (and elsewhere) when dual feeding isn't the 3-2 valve supposed to be blocked forward? Would this have anything to do with the harsh 3-2 shift? I don't know enough about the function of the 3-2 valve to know.

RemoveBeforeFlight

I don't know if all do it, I didn't, Chris said to. Is it supposed to be blocked open toward the pin?

 

[mikestertwo]

I don't know if all do it, I didn't, Chris said to. Is it supposed to be blocked open toward the pin?

No. Block it in the direction the spring is pushing the valve. The valve is normally open at low speeds. At higher speeds (above 50mph) governor pressure closes the valve to restrict the oil bleed off from the 3rd accumulator.

 

[77 cruiser]

Thank you.

 

[77 cruiser]

Went back to the GN servo , slight softened the 1-2 & 2-3 & it took some harshness from the 3-2 downshift. I don't think it will chirp direct now.