I had a trans-go shift kit installed into my 4L60E and I wanted to know if there is anything that can be done about the rough 1st to 2nd shift that I now have from the kit. I also have sonnax billet servos on if that matters. The truck is my daily driver and work car.

I have had my everyone from my clients to my friends asking me why I am driving that rough. Is this something I must live with or can the pressure somehow be turned down?

 

Rough as in firm? Billet servos and a stock torque converter are going to give you a very firm 1-2 shift. The shift kit is adjustable tho, with washers in the 1-2 accumulator and different springs in the 1-2 accumulator valve. Also, the seperator plate can be drilled to different sizes to adjust shift firmness. On a stock converter I would drill the shift holes to no more than .093. I would ask whoever installed the kit what the plate was drilled to, and I would take the 2nd billet servo out and replace it with a 093 corvette servo and leave the 4th gear billet servo in. Just my .02

 

Shift pressures can be adjusted with tuning software as well.

 

I'm with him.. Stock converter with shift kit and servos hurts.. I broke 2 output shafts from it shifting too hard.
replace the 2nd servo like he said with the Corvette one. that should tame it down..

Is your truck tuned?

 

1. if you previously had a tune that increased line pressures have them returned to stock.

2. if you put one washer shim in take it out...i had one in mine and it shifted way to hard

 

Its rough as in jerks your whole body forward very harshly in the 1-2 shift. Whats the difference between the sonnax servo and the vette one other than the sonnax being billet? I am going to ask them tomarrow what they drilled it to. Thanks for your suggestions.

 

Hmm thats interesting. I just had to have them do a full rebuild on the trans a 2nd time in less than 3k miles. I have asked the shop if there was anything they could do to make the 1-2 shift not as rough and they said there wasn't. It makes me wonder now because it was my output shaft that stripped and they tried to blame it on my having 285mm tires and the AWD. I drive the truck hard but not abusively, like no burnouts just spirited straight line runs.

Yes I had my truck tuned when I put on the blower and thats when I had the shift kit put in so the tune was made to go with the kit. When I picked up the truck last week they asked me to have the tuner turn the line pressure down a little.

 

I will have to ask them about the washers. Will they know what I am talking about if I say the "washer shims" or is there a different term for that?

 

You stripped a output shaft? wow, i thought they just broke.
There are ways of taming the 1-2 shift, if you have stock Servos laying around id try them.
Who tuned your truck?

 

Have them return the 1-2 accumulator assembly back to completely stock its easy just drop the pan and make sure your line pressure with the harness unplugged from the trans does not exceed 230 psi do this and you should end up with a much more tolerable part throttle shift feel . They should check the line before pulling the pan as they may need to turn down the PCS some.