2-3 Shift bind up

[lost2a6]

At light throttle I'm having a slight 2-3 shift bind up. I was hoping some one could give me some ideas. I don't feel it at WOT because of excessive tire spin. Build up is as follows: Mike Kurtz shift kit (his modified version of the old Trans Go), PTS Extreme band, servo, and pin set at about .040. PTS Extreme billet forward drum. Blue plate specials in the direct set at .030. PTS pan with rear pick up. 1-2 and 3-4 servos are blocked off (none fuctional). Center support seals are teflon along with the forward drum and input shaft. Trans pressures are great. I was thinking of possibly drilling out the 2nd release hole some, although I don't wan't to create a 2-3 flair at WOT.
Thanks

 

[chris718]

the problem is the band is not coming off before the clutches in the hi drum .this can be caused by spacer plate mods as well as leaks or incorrect pressue build up in the third accumul;ator circuit .aftermarket servo volumes are also less than desirable aggravating the problem tight band clearances reduce band clamping forces .install a stock plate and if this doesnt help ,install a 1/8 inch orifice in the case at the direct clutch feed hole using a 440t4 front wheel drive governor plug or equivelent.you must drill it to 1/8 inch and this should cure it .part number for the plate is gm 8657309 .or contact ck performance.com for the parts .these plates provide killer shift quality without opening up the feed holes in the plate.

 

[lost2a6]

Chris, Thanks alot for your reply. I have a suspision of a possible leak. One of my center valve body bolts didn't want to hold the torque, so I'll go ahead and put a heli coil in it. I thought about the bigger servo requiring more oil to release it , so while I was at it I was thinking of increasing the 2nd release hole by .010. About restricting the direct clutch feed hole, wouldn't this possibly cause a cushy 2-3 shift?
Again thanks Steve

 

[chris718]

no problem. it will make the 2-3 shift firmer w/ the orifice because it allows higher pressures to build in the circut before applying the direct clutch and knocks the band off quicker. we also dual feed the direct drum by using the reverse piston area in 3rd.