High pitch noise while accellerating under load

**6T7GOAT** · 02-28-2009, 07:49 PM

1st I would like to say that this is a great source of info, I have learned a lot by ready many posts. I have a annoying issue with my 2006 silverado 1500 crew cab. The truck has the 5.3 engine and auto trans with 3.42 rear. The problem is that when I am accellerating under load at about 1500 rpm's I get a very high pitched whine. It happens in every gear and only occurs when accellerating no matter what gear i am in it occurs at the same rpm. It is not an intermitant sound it happens every time I drive the truck. I don't notice any effect on the performance. I dont believe it is wheel bearing or a belt. Anyone have any suggestions. The truck has 53000 miles on it and other than this noise everything else is great. Thanks for any help.

**k.daddy1** · 03-03-2009, 10:01 AM

You might want to check the u-joints. They may not appear to be bad, but if they are dry from lack of grease, also check the fluid level in the diff. It could be low on oil.

**bry2500** · 03-03-2009, 10:20 AM

I'm gonna go with it's the diff. I had a bronco that made that noise just before it blew the rear end and then the same thing happened to the front diff.

**mrfixdit** · 03-03-2009, 07:14 PM

Does the noise happen when cold and/or warmed up? Does it stop making the noise at higher RPMs than 1500 ? Does the noise change as the RPMs increase? Can you hear it when in neutral? I once had a strange screechy whistling kind of noise that turned out to be that corregated protective tubing that keeps your wires all bundled up nice and neat. The slit in the tubing was facing just right where it was catching air from the fan and acting like a whistle.

**jim1958** · 03-03-2009, 07:51 PM

Whole lot of variables? It`s a 2006, fairly new, I`m not buying it being a differential problem it`s too new. We need to know more about it. Check the carrier bearing, clutch fan, idler-tension pulley, alternator bearings there`s just a lot to look for by the way you describe it.

**6T7GOAT** · 03-05-2009, 08:03 PM

Thanks for the suggestions. I got to play around with it a little this week. I could not stand the semi metallic front brake pads so I put ceramics on. I made sure the air intake was completely sealed and not whistling. Also checked U joints and rear and they are good. I also sprayed down the belt a tensioners with silicone to se if it would quite it and it did not. The sound I am hearing does not vary in pitch at all and it only happens at about 1500 rpm. It does it in every forward gear and only when uner load or accelerating. It will not make the noise if I am in neutral or if i am decelerating. I was reading somewhere about a possible issue with the torque converter. Any body have any more insight? Thanks for the help.

**DocEvil** · 12-07-2010, 01:53 PM

Did you ever find out what it causing this? I have a similar "whistling" noise which happens only when in motion. I can hear it when I reach 45kpm and right up to 100kph (60mph) It's definitely not coming from the engine because if I slip it into neutral, it's still there. The noise is also much more noticable when it's cold out (below freezing) and tends to go away once the truck has been driven for 5 miles or more. I pulled out the rear seal, greased it and that did not fix the problem. All the fluids have either been replaced or are up to capacity. The u-joints and center bearing are fine as well. If I let off the throttle slightly, the noise will lessen but once I put it under some load, it comes right back. I'm having no driveability issues, the truck shifts fine and there is no reduced fuel economy. Just an irritating noise. This leads me to believe that some impending problem will arise.