transmission/drivetrain noise

mossgold · December 19, 2006

Hi, I have a 02 reg cab/swb 5.3 auto silverado.

I know that it is hard to diagnoise "noise" problems over the net, but thought I would give it a shot anyway....so please don't anyone bite my head off.

First of all, the truck has a little over 56k, and the trans was professionally rebuilt at about 47k. The trans went out while pulling away slowly from a stop sign. Luckily my dad was driving and not me. The trans tech said that a housing had cracked (and eventually stressed from normal driving), most likely from being put in park by previous owner while still rolling at some point in its short life. There is a faint rattling noise that can be heard while driving at around 1500 rpm, in both 1st, and 2nd. Noise could be compared to an alternator/pulley bearing, but have ruled this out with extensive experimentation. Not a constant noise and can't be heard if going any faster than what you could drive letting the trans shift itself in either gear.

It can sometimes be slightly heard for a split second when revved to 1500 rpm but just for a second in either park or neutral. It can be heard constantly if footbraked and revved to right around 1500 (give or take a grand). There is no trans "whine" and shifts/engages flawlessly.

Just thought I would throw this out there to see if anyone might have an idea of what could cause this noise in a transmission. I have had my father footbrake truck and have looked under truck (cautiously) and don't think it is a u-joint. Any insight would be much appreciated.

Giant · December 19, 2006

This is a wild guess, I've never encountered a problem like this. BUT...

Could it be the TQ converter? by just hearing it in that range, and then only when a load is put on it in that range, the only thing I can think of could be the TQ converter.

keep us up on if you find it. I'm curious

mossgold · December 20, 2006

Thanks for the suggestion Giant.

I have been doing a bit more research, and I am thinking it could be a pump based on the fact that I can hear it a bit in Park and Neutral keeping in mind the webpage below about trans noises.

http://transmissioncenter.net/Transmission_Noise_Help.htm