I am building a 700R4 using the TransGo 2&3 kit, and have a question about the Servo setup. I'm using a Corvette Servo, and instead of discarding the Snap Ring and center Cushion Spring as the instructions state(arrows in illustration below), we are going to retain them both, so that we don't get any 3-2 downshift clunk or anything. The other question I have is about the Yellow Spring(circled in illustration below)that comes in the TransGo kit that the instructions say to install under the Servo Cover. I was just wondering what exactly it's purpose is? Is it a good thing to install, or leave it out? Pictures attachment below.... Thanks!

 

Those Instructions are intended to be followed in their entirety.

I do not recommend "picking and choosing" only certain portions of the Instructions without an excellent understanding of what you are altering.
...and I understand that, this is why you are asking the question that you have posted.


Your question is actually rather uncomplicated and reasonable, however...

I find that answering your question in an environment such a this Forum to most often do more harm than good.
There are simply too many small details/ changes/ aspects (of both Hydraulic and mechanical changes) that will alter the final outcome.
Too many variables, too many components that alter more than one function/ system.

I personally throw that Page of the Instructions in the Trash (I do not like those modifications).
There are other Products/ Parts and/ or Hydraulic changes that I implement to attain the Servo Function that I desire.
However those instructions do serve a purpose... and there are situations were they are beneficial.

My best recommendation from here would be to contact Dana (Member PBA) of Pro-Built Automatics and see if he has the time to go over all of the details of your build, and all the intricacies of the alterations that can be done with that "Shift-Kit".

 

I also just wanted to mention that those Instructions (and many other TransGo Instructions) used to be (30 Years ago) very highly detailed with explanations of how the instructed changes would affect different aspects of the function of the Transmission.

However, it was too much reading for most DIY enthusiast to read... and hurt sales.

The Instructions looked too involved/ complicated to people (other than those already educated/ Professionals) and scared people/ potential customers away.

 

Ok, for future readers that has the same question I did above, here is the answer. I talked with Dana at Pro Built earlier today, and the Yellow Spring that comes in the Transgo kit, that is installed between the 2-4 servo cover and the 4th piston, is intended to make the 3-4 shift a little quicker, so we will use it. However, we will be retaining the Snap Ring and OE Cushion Spring that the TransGo instructions say to discard, so that we don't get the dreaded harsh 3-2 downshift clunk.

Thanks

 

Be careful not to minimize (less than 0.040") the 2-4 Band/ Intermediate-OverDrive Servo End-Play/ Clearance with the referenced OverDrive Servo Piston Yellow Apply Spring... as well as be mindful of the OverDrive Servo Apply Feed/ Separator-Plate Orificing.
The Band can drag and burn-up if not following a Build Recipe from Instructions or a Builder (Like Dana/ PBA).


Adjustments may need to be made regarding the 4TH to 3Rd Downshift Speed/ Feel.


Alterations like this remind me of when GM sold "Full Throttle Up-Shift: Throttle Valve Plunger Sleeves over the Parts Counter...
When installed into a completely Stock THM700-R4, the 3-4 Clutch and 2-4 Band would both be burnt-up in a short amount of time.

 

did Dana not recommend putting slots in the steel cover? Transgo does this in their SK and SK jr kits.

 

Good afternoon, he didn't mention nothing about grinding the steel cover, I noticed the SK kits says to do it, but the 700 2&3 kit we are using doesn't instruct you to do that modification for some reason.

 

The Instructions do not say anything about the Steel-Cover for the Servo, because the Instructions tell you to remove the cushion Spring, and solid stack washers in place.

The 4 Holes in the Steel-Cover are to allow ATF to move in/ out of the area where the cushion spring goes.
If ATF could not exit that area with the cushion spring... the spring can not actually cushion very much.
The ATF acts like a solid spacer.

 

vorteciroc, do you add a spring between the 2-4 servo cover and the 4th piston like Transgo does? I have not heard of other builders doing this.

 

No, I do not.

I make hydraulic changes to the 4th Feed Circuit as needed instead.