I just had my tranny built and drove it for the first time today and it wont shift from first to second unless you let off the gas? The tranny has billet servos, .490 boost valve,high output pump slide spring, intermediate servo release check valve, with the hole drilled in seperater plate per instructions. Anyone know what could cause this? Oh and if you got WOT it will just bounce off the rev limiter untill you let off the gas then it will shift to second.

 

When it eventually makes a 1-2 shift, is it a soft or firm shift?

Did your builder use a machined reverse input housing?

Are you certain he got the servo apply pin length correct?

Shouldn't your transmission builder be figuring this out?

Frank
CPT

 

I agree with Franks last line. Make sure he knows there's a problem as soon as you can.

 

Yea when it eventually shifts its a firm shift. We used the same reverse input drum and 2-4 band The drum was still straight as an arrow without machining it, The only thing wrong with the tranny when I took it out was the 3-4 clutch pack, It still shifted fine from first to second. We used the stock servo pin without the supplyed pin extender. He will be back from vacation monday I will let him know. Oh and he did put a 1/4 turn on the force motor as well.

 

Are you using the same stall converter or did you put in a different one? What stall speed?

 

Same converter as before 2000 stall.

 

Anyone have any thoughts on why it wont shift?

 

possible valve body issues, debris in valvetrain, stuck valves.

 

Problem solved! Turned out to be the servo seal got cut in half when he installed it, Works Great now. Thanks everyone for the help.

 

Hmmm. I guess he didn't air check the servo when he assembled it? That's common practice for a professional.

Frank
CPT

 

Lol, do I detect a hint of sarcasm there Frank? Im a trans. builder myself, and I usually air check everything. Force of habit I guess. Only takes a few minutes.

 

Well the problem is back it dosnt like to shift from 1st to second at wot. Sometimes it does sometimes it dosnt. It only has 2000 miles on the rebuild and I have a fuddle 3000 stall now, could this be stall wall? I am still on stock tuning.

 

Stall wall isn't usually an issue until 3200 stall. I'd guess you're having more transmission issues with the 2-4 band apply.

Frank
CPT

 

whats you rear end ratio ? It can decide wether a 3000 stall can have and impact or not I have seen 2.73 camaros have the stall wall issue !

 

yup I got the 273's but will be swaping in 373's soon. It shifts fine when not at wot, It shifted fine at wot when I first took it to the track then one day it just didnt want to shift 1-2, At the track it did bounce off the rev limiter on the 1-2 shift on a nitrous pass, My fluid still looks and smells brand new, I'm hoping this is the stall wall issue I can work out with tuning.