i am not 100% sure but i dont think my 4l60e is locking up on the highway. the main way i checked this was to touch the brakes and it didnt raise in rpm at all. when i press a little harder on the gas it doesnt raise in rpm at all either unless i punch it.

speartech harness, 2000 5.3/4l602, wait4me performance reprogram.

also it doesnt shift very firm, i replaced both servo's with tci billet servo's and put the .490 boost vavle in there too. i told jesse i wanted it to shift firm and it shifts from 3 to 4 like a caddy, so soft you cant even feel it.

there was 26k on the tranny before i put it in, and the tranny was out of a 2003 blazer with a 4.3

 

What are you using for a brake light switch? Are you sure it's wired correctly? If i remember correctly, in an F-body harness the brake switch should have power on both sides of the switch with the pedal released, but the trucks are wired differently. I can't find my wiring diagram at the moment,as I'm leaving for work but I can find it tomorrow and let you know.

 

there are 2 wires on the speartech harness, if i understand it correctly one is the 12v source and one is not, connected together when the brake is NOT depressed, and they disconnect when the brake is pressed.

also i niticed tonight that the tranny shifts like mud, it shifts very low like 1500 to 1800 at half throttle, and it doesnt want to downshift unless you floor it.

i am not impressed with the shifting, if i shift it manually at 3k, it is a very nice firm shift, but isnt harsh at all. i just wish it shifted like that normally on its own.

 

Scan the system. You should see how the programming is set...

 

ok, i called performabuilt transmissions today, talked to Frank. he told me how to check to see if the TC was locking, i wasnt touching the brake long enough while still applying gas, it did go up 300 or 400 rpm. it still shifts sluggish, he suggested a transgo hd2 shift kit and told me how to bump my line pressure. he suggested 220, no more than 225. Jesse at wait4me said he set it at 210 but Frank said he cant set max line pressure with the computer, just the shift pressure.

Jesse said my 4.3 4l60e was weak, 4 pinion planet, where 5.3 has 5 pinions. and he claimed i have less frictions in the v6 tranny. Frank says they are the same in that reguard, all 4l60e's have 4 pinion planets, and 4l65e has 5 pinoin planets.

this all sound about right,

 

I would not trust much that jesse has to say.

Like others have said try and get someone to check the PCM programming if you can.

 

Just looked at the stock tune on my 07 4L/5.3 combo:
High psi adjust can be modified to limit the shift PSI, [via trans adapt values], at all shift patterns.[From 20KPA to 160]
The graph is KPA vs engine torque in Nm.
I would think that by raising the limit[s], at the lower torque input levels, the shift feel would be changed....
Stock program shows max psi is attained 360Nm.
The shift points max psi can be varied by changing the base pressure, IE {D0701}. 1-2, in this case.
{3801} Force motor current, looks to be a way to set the final line psi. [55 to 230psi] Some trans temps are involved.
Looks like there are several tuneable features, that may well be used to improve the trans???
I use EFI LIVE 7.5

 

i wish hp tuners wasnt 500 bucks, i sure would like to mess with all this stuff myself