those with 4l60e/4.88/35 tires experience

[trx88]

Just wondering if anyone has ever driven a non speedometer calibrated 4l60e truck with 4.88 gears and 35 tires.
my trans is acting goofy and i cant figure out if its cause its time to be fixed or if the ecu is out of calibration
the truck shifts from first to second to third, but in third if i dont keep my foot in it, it goes into 5 or final drive...
sometimes at very low speeds/rpm - im thinking its because the vss at the driveshaft is telling the ecu that its spinning to the equivalent of 70 mph but im only going 50.

that or my trans has on me once again

 

[JonZ71]

what year truck

 

[88GMCtruck]

Well, there is no way to tell which is the cause. I would start with calibrating it first, because it should be otherwise you risk damaging it. Once you calibrate it you'll know if it is damaged or not.

Friend of mine had stock 3.73s on 35s and his 4L60E wasn't very happy until he re-geared it.

 

[trx88]

its a 96,

it was pissed every time i put it in D with 3.42's

now it has 4.88 front and rear

 

[trx88]

I bought a jet accuspeed digital recalibrator, a box with a harness that plugged in and adjusted the signal from the vss, but it never did anything. The ecu throws no codes either.