i was installing an hd-2 on my car today and when i went to install the cushion spring in the servo i noticed the first spring that goes in b4 the pin was not there. i searched but could not find much info on besides it being called servo return spring. does the transmission need it so i can find one to put in there. why would it be missing. maybe the last place that rebuilt it left it out?????

 

Many builders I have noted leave it out with the stock style servos and I have never noted any issue , I have torn units down with 100000 miles on them and found it to not be there and all look good. Since it would reduce resitance to second apply and reduce 3-4 clutch accumulation it would firm up the 1-2 and 2-3 shifts a little . Now with the super servos such as the fairbanks and the sonax it is required as they dont have enough area behind the servo for the 3rd clutch oil to properly relase the servo.
Hope this helps

 

Those double springs are supposed to be in there. Those springs as im sure as part of the other accumulators are part of a Superior 4L60-E shift correction kit. Just so everyone knows.

 

although you kinda dug up a dead thread- since i recently encountered this, id like to chime in. also, poster above- i think your thinking of the 1-2 servo cushion springs, that go inside the front half of the 1-2 servo yes those are critical.

however- (first let me begin by saying, i have never heard one bad thing said by anyone- customer or vendor- about Performabuilt. we are not a trans specialty shop, i just happen to build a lot of GM transmissions lol. pls dont take this as "calling you out" or wrong... just my .02 )
this 4L65e i just did was doing exactly what i would suspect one to do if it was missing the 1-2 servo release spring... burned the **** out of the band and drum. if you think about it- unless said builder who, for god knows why, decided he was smarter than Sonnax and GM engineers, removed the return spring... also decided to enlarge the 1-2 exhaust holes/orfices, your burnin the band up. period. DO NOT LEAVE OUT THIS SPRING!!! this particular trans had a few other hiccups from misguided builders, but none that would cause a DECIMATED band and drum. no spring causes the servo to release too slowly, and drags the band longer than it should. this car had a vette servo, and yes i totally agree with Performabuilt that the larger apply area of the servo, the worse the effects. i just feel you werent clear enough that on ANY sort of HD or performance vehicle, especially, leaving this out WILL destroy your band and possibly band drum. theres a GOOD reason not ONE of these few well known huge transmission performance parts companies (TransGo, Superior, Sonnax, etc) have you remove- let alone even change or add to the return spring. ALL of them have you leave it alone and reinstall. sorry for the long post/rant lol, ive just come to find that literally a minimum of 80% of the "tricks" i learned in school and from my ASEP mentoring of trans builders, is absolutely WRONG and honestly helps lead to the opinion that "all 4L60e's are garbage and cant handle ANY power!!" are they outdated? yes. were they designed for 200 hp V8's in the 80's? Yes. Did GM simply throw a more modern valve body and minimal upgrades and start putting it in 5800lb, 400hp AWD trucks? They sure did. BUT this doesnt mean one cannot be properly assembled, now days, (mostly thanks to Sonnax) to hold decent power. ok rant off lol

John