2 to 3 shift problem

[KENTON]

I have a 69 Roadrunner that seems to have a problem going from 2nd to 3rd. It acts like it can’t make up its mind on which gear it wants to be in. It shudders for what seems like a second or two, then goes to 3rd. It doesn’t do it all the time, but probably 3 out of 5 times.

 

[493 Mike]

Has the KD band been adjusted properly? I'd start there and check the KD linkage adjustment too.
Mike

 

[Bad Sport]

It shudders for what seems like a second or two, then goes to 3rd. It doesn’t do it all the time, but probably 3 out of 5 times.

Did it just start doing it out of the blue?

Light throttle or hard throttle? Both?

If it's doing it on light throttle, I would try adjusting the throttle pressure linkage.......first.

 

[KENTON]

Has the KD band been adjusted properly? I'd start there and check the KD linkage adjustment too.
Mike

The band is 72” pounds and backed off 2 1/2 turns. The kick down is adjusted according to the FSM

 

[KENTON]

Did it just start doing it out of the blue?

Light throttle or hard throttle? Both?

If it's doing it on light throttle, I would try adjusting the throttle pressure linkage.......first.

It is hard throttle only. I rebuilt the transmission and it has done it since it was finished. Drove it that way for a couple of years. I don’t normally drive it very hard. I have rebuilt 4 or 5 727s and 1 904 and never had one do this.

 

[KENTON]

I cannot remember if I put a Transgo shift kit in this one or not.

 

[Cranky]

Not sure if turning the band in a tad more than 72 inch pounds or backing it off less would help or not but I know what having the low reverse band too tight does Had transmission guys tell me that going totally by the book isn't always the best thing especially when the trans has been modified. Don't know if that's a line of BS or not as I'm not trans expert but more of a novice.

 

[dvw]

My bet is the high/reverse clutch is slipping. The band applies only in 2nd gear, then releases on the 2/3 shift when the high/reverse clutch applies. Could be high /rev piston seals or reaction shaft sealing rings.
Doug

 

[KENTON]

My bet is the high/reverse clutch is slipping. The band applies only in 2nd gear, then releases on the 2/3 shift when the high/reverse clutch applies. Could be high /rev piston seals or reaction shaft sealing rings.
Doug

I don't feel a slipping thing, but rather a trying to be in 2 and 3 at the same time. Like the band is not releasing fast enough. When the servo that holds the band in releases, where does the fluid go? Is there a spring that forces the fluid back? I can't remember. Could the spring be weak? I Just can't remember, it's been a few years since I did one.

 

[KENTON]

Not sure if turning the band in a tad more than 72 inch pounds or backing it off less would help or not but I know what having the low reverse band too tight does Had transmission guys tell me that going totally by the book isn't always the best thing especially when the trans has been modified. Don't know if that's a line of BS or not as I'm not trans expert but more of a novice.

I was wondering about going a little looser on the band. Seems like I read that once before. I know when you take one apart there is a lot of play on the band, and they are not slipping.

 

[493 Mike]

I was wondering about going a little looser on the band. Seems like I read that once before. I know when you take one apart there is a lot of play on the band, and they are not slipping.

The guys at Transgo have played with a couple different band adjustment techniques over the years, by-passing the FSM specs. It won't cost anything to try some different clearances.
Mike

 

[dvw]

I don't feel a slipping thing, but rather a trying to be in 2 and 3 at the same time. Like the band is not releasing fast enough. When the servo that holds the band in releases, where does the fluid go? Is there a spring that forces the fluid back? I can't remember. Could the spring be weak? I Just can't remember, it's been a few years since I did one.

If it overlaps, it'll tie up in 2nd and 3rd together. At low speed it'll feel like a very hard shift. higher speed should be fine. I suppose it's possible it broke a KD servo release spring. But I've never seen one break.
Doug