Originally Posted by lostinNC2
I'm trying to narrow down the millions of possibilities that "it could be" and I know trying to describe what this fells like without being in the truck is near impossible. I have a Chevy K1500 Silverado with a 5.7L and a 4L60e trans. I have done all the mechanical work to her since I bought her in '97. I have changed the oil every 3k to 5k and the trans fluid every 15k to 18k. I haven't had a bit of problems until now. After changing the trans fluid last weekend it now has a "surge". this is tough to describe. I can feel it only in overdrive and when it's under a small load. almost as if one of the solenoids isn't holding it in gear, just for a split second, lets go and immediatley engages again. if I give it more gas, it downshifts and goes. if you hold the gas pedal steady under load, it almost fells like it jerks but not violently. you feel it more in your seat. I don't know how else to decribe it. I'd rather not put a whole lot of money in it but it is my only set of wheels. I'll do what I have to. she has about 240k total miles and is really clean. does anyone know how or where I can learn to check those solenoids? or any other options?
thanks for your time. C
from what it sounds like, its the torque converter cycling off and on, we have 1 in the shop right now doing the same exact thing. best way to know for sure is when you see the tach needle come up pull the gear shifter down into drive, if the rpms come up more, then its t.c.c., if the rpms dont change, then its a possible shift solenoid. usually they will throw a code for a shift solenoid problem. most of the time, if theres a t.c.c. problem, it also can throw a code, but not allways, ive seen a faulty tps cause the problem and not throw a code.