1-2 shift shudder, please help

silverado4800 · February 4, 2004

Hey, im new to the forum and i have a question about my transmission. It has a shudder when it shifts from 1st to 2nd gear, and just a small shudder when going from 2nd to 3rd. And usually only when the throttle is between about 10% and 60%. I have read about this problem all over the internet but have yet to find a solution. I tried the fix that deals with the alternator interference but that is not it. I think it is computer related. I have a predator programmer and i can program it or reflash it to stock and the shudder will go away for 100 to 150 miles then slowly start to come back, kinda like it has to learn to shift like crap. And it has done this since i have had the truck so i know none of the mods i have done caused this, which i haven't done any to the transmission anyways. Does anyone know of any other fix, i feel like putting a bullet in my transmission sometimes. Any help would be appreciated.

silverado4800 · February 4, 2004

Hey, i forgot to add, my truck is a 2001 silverado 1500 with a 4.8L and 4L60E

Wingnut · February 4, 2004

My '92 does that when it's overdue for a tranny service.

Just a thought.

Welcome to the forums by the way.

silverado4800 · February 5, 2004

Yeah ive thought of just changing the fluid and see what happens, just hate to shell out 100 bucks to get it flushed, im thinking of trying the Autotrans Interceptor, it says it will "clean" up the signal going to the transmission, which seems to be the problem, like the computer is sending the pressure solenoid a crappy signal, after that i will probably try changing fluid, i guess its about time anyways. then if that doesn't work i guess ill just have to scream. thanks for the input wingnut.

Import Hater · February 6, 2004

So you did the entire TSB that deals with the alternator "sense" circuit?

Rob

silverado4800 · February 6, 2004

I did the test where u disconnect the computer connection to the alternator, it turns the alternator off, therefore removing the "interference" and it did nothing. I didn't realize it actually turned off the alternator, i thought it was a sensor of some sort. But when i plugged it back up with the engine running it lugged down so i could tell the alternator hadn't been running.

Import Hater · February 7, 2004

I'm not sure if it says anything about testing the condition that way. It honestly wouldn't hurt to put on the parts in the TSB. It's only like $10 worth of parts at the most. And maybe an hour of your time.

Rob

2002SierraSLE · February 24, 2004

I've had this same problem with my 2002 Sierra 5.3 4L60E since I bought it (started occuring at 3500km). It's been in for service countless times and they've never fixed it. I know all about the wanting to shoot the transmission bit... especially when it's 30 celcius outside, the roads are jammed, and it's still an hour home... with what feels like 10,000 more shifts to go.

Goes away when the weather gets cold though...