4T65e-HD

[572MonteSS]

Hey i need some help with the 4T65e-HD trans. It is the trans used in the V8 Impala SS and Grand Prix GXP. Im working on an 06 GXP and i do not see a table for the desired shift time. This is causing me great pain because with the line pressures upped and a shift kit i get long shift times causing trans shutter. Any help is appreciated Thanks.

[mattgallan]

Same issue...subscribing

[chrisb]

i believe it takes a several key on and off cycles for the pcm to relearn the shifts again after installing a shift kit or increasing line pressure. mine was horrible after i increased the line pressure after about a week it was nice and snapy. i thought those cars came with a 4t80e trans?

[mattgallan]

One thing I tried that works is give the transmission back some torque management so it can shift faster. Helped alot with my problem.

[FF481]

I have the same problem too on my 07 Monte SS. If you increase the pressure you will get shift shutter. I have not tried it long to see if it goes away like someone else has stated in this post. I do not understand why it does not give us the parameters to change the shift time. Is this something GM built into the programming?

[FF481]

Any updates to why there is not a place to change the "desired shift time"?

[Nick 2K2 SS]

There are some basic shift time paramters shown in the Beta version of HPT. You'll have to e-mail support asking for Beta if you want it.