Hi guys, I have a low mileage rebuilt 700$R4 that I just got, and it is flaring the 1-2 shift really bad only at fairly heavy throttle. TV works fine.

How do I adjust the bands in this trans? I have only rebuilt Chrysler 727/904 autos and the intermediate band adjusts externally on those transmissions. Obviously the 700R4 is not so easy to adjust.

Specs and instructions would be super!

Thanks

 

can't adjust the bands on 700's. you need to replace the 1-2 servo with the 094 (corvette) type and put in a larger boost valve. both peices shouldn't be over $40. (local shop here sells the servo's for $14.95 and the .500 boost valve for around $20 i think)

 

I have those parts but have not installed them yet. This is not "normal" operation of this transmission, I want to get it working right before I start throwing speed parts at it. The engine rpm's run away to overrevving when it does the 1-2 shift. Like I gain 2000 rpms during the duration of the shift. That is not normal.

 

Springs behind the servo, band should have 1/8-1/4" play side to side.

-- Joe

 

Thanks Joe, is there anything specific I should be looking for w/ the springs?

 

I'm not an expert, but the manual I have said something like "add two springs, put the assembly in, cover on, snap ring then check band tension" and keep adding or taking away springs until it was right.

Too much tension and it burns the band out
Too little and it burns the band out.

I scratched my head too, but seemed to have got it right.

-- Joe

 

I want to say that you install your servo without the outter o-ring and push the assembly in by hand and see if you have about an 1/8 play.

 

On a 700r4/4l60/4l60e trans, the servo is not adjusted. Gm (and rebuilders) use a 1,2,3 or wide band pin (selective length) to set it for the life of the trans. The gm tool will allow approx .100-.160 sevo pin travel, and still be considered ok. I normally aim for .085 of cover travel. I try to stay within.010 of that number. Others may agree, or disagree.

 

The kits I've seen and used all came with shims for the servo. Is that an aftermarket approach ?

-- Joe

 

Ok these are the type of answers I needed. I appreciate it!!

 

It is.
Transgo eliminates the spring and uses spacers to set the pin. Gm matches the selective pin to the case/band/drum combo.They have a go/no go guage to measure it. On most of the overhauls I do, I wind up using the longest pin they have, and if needed, grinding it down slightly to give the travel I wish it to have.