dirtsurferus

I just recently bought a Silverado 1500 4x4 LT with the 5.3L. This is my first chevy, but not my first full size to have this issue. the truck has 150k miles on it and I got it two weeks ago. actually 2 weeks ago today....every gear shifts perfectly and smooth as can be (I have to pay attention to feel it shift its amazing). However, just today (about 30 min ago) i noticed that going down the highway i could hear the engine a lot more than usual (factory pipes) and then noticed the tach was right below 2grand cruising at 60. i stopped and turned the truck off after putting it in park and then started it and pulled back on the interstate and counted the shifts and its not shifting into OD gear. only shifting 3 times. My last full size to have this problem was a Ram 1500 with the terrible auto tranny line in it and it ended up needing to be rebuilt :/ hence my worry. I did notice that the manual says to change the fluid/filter every 50k miles and as far as carfax and i know, it hasnt ever been done. I am trying to avoid having to take it to the dealership in any way shape or form. idk if it will help any but here is my vin: 2GCEK19T141284333

Allan In NE

I'd be for taking this truck right back where I got it and raisin' a little "issue" with 'em.

Allan

spyncycle

The VIN shows it to be a 2004, which has the 4 speed transmission, 4th being overdrive. 3 shifts from starting would place it in 4th(Overdrive) gear. What might be happening is that the lockup torque convertor isn't engaging, which would allow some slippage and a higher engine RPM.

If you think it isn't shifting into 4th gear, then at highway speed pull the gearshift down to 3. If it doesn't downshift, with an increase in RPM, then that would prove it isn't shifting into 4th. If it does downshift, then nothing will be harmed, since 3rd gear is acceptable for highway speeds.

dirtsurferus

what do you mean lock up torque converter? i thought all automatics were 5 speeds :/ nothing like feeling like an idiot to put a smile on your face haha what is a good rpm for highway speeds? like..say 60 mph. on my old truck it was right below 1500. yesterday the silverado was around 1900 or so. I called the dealership and they are going to do a diagnostic and check it out on sat but that was when i thought it was a 5 speed. on an unrelated note... the automatic 4wd.... if i push the button for 2wd it only stays in 2wd until i turn the truck off. when i turn it back on then it is back in auto 4wd. every now and again it stays in 2wd. is that supposed to do that? hate to sound so ignorant but ive only had the manual kind up til now... thanks for all the feedback!

spyncycle

After it's in 4th gear and you're running steady, the convertor will lock up to prevent slippage. You can see the RPM drop slightly, which may have led you to think you have a 5th gear.

In my previous truck, a 2002, I ran about 1900 at 70 MPH, but I believe it had a low geared axle.
In my current 2004 I run over 2000 at 70 MPH, running 3.73 gears, so 1900 at 60 could be right if you have 4.10 or the very common 3.73 axle ratio.

The jump from 2wd high back to auto 4wd is not normal. It should remember what it was left in and still be there after a stop. Could be a poor connection at the back of the 4wd selection switch or something more serious. If it is consistent then the techs should be able to find and fix it.

Welcome to the Chevy truck world, I hope you enjoy it as much as the rest of us.