Chevy & GMC Vans

I get a whining sound when driving uphill at around 60km/h or more. It's worse when turnining. I'm pretty sure it's coming from the front. What could this mean? What can I check for?

Check u-joints, check wheel bearings and check oil levels in the diff's. Go from there.

Anyone know offhand if the front differential has a drain plug, or if you have to suck it out?

There is a drain on your 2000.

Both front wheel bearings are new. Fluids were all replaced. U-joints appear to be OK.

New or not, I would be taking a look at those front bearings.
Even new ones can fail.

Two things come to mind. Transmission pumps whine. Power steering pumps whine.

Good point.
It seems to be louder when turning ... points to power steering. (not so bad)
Also louder when hot ... could point to transmission. (bad)

I don't think bearings "whine" like this. Bearings tend to screech, squeal or rumble. This is more of a gear moan. Plus the sound stayed exactly the same before and after changing the bearing.

Are there any troubleshooting steps I can take to narrow this down?

my initial instinct was power steering pump as he said he hears it while turning, i know mine is noisy and actually seems to dim the lights if i turn the wheels while sitting still. the 60mph thing doesnt make sense if its the ps pump though, you think thats the tranny pump smiles? 60 km/h not mph, damn cannucks

A bearing will produce a cyclic sound when going bad, it will not make a steady noise unless it is completely shot and you would know if it's completely shot. Your wheel would be flopping around.
To determine if it is your p/s pump, drop your accessory drive belt and take it for "a quick drive".
Your tranny will hold heat longer than your engine will, so get everything up to operating temperature, let it cool a bit and then take it for a quick drive.
It shouldn't take you long to get up to 35mph/60kmh. (damn Americans)
If the noise disappears then at least you have determind that the tranny is ok and it may be the p/s pump.
Also, if you turn the wheel from left to right while sitting still does it produce the noise, and does the noise change when turning the wheel to the right as opposed to the left?
The clutch on your a/c compressor can make funny noises as well, but once they do start making a noise they usually fail quite quickly.


Peter

It's the same left and right, but only while in motion. Definitely constant and not cyclic at all.

Driving without the accessory belt could prove difficult. At 60km/h and no power steering, it will be very difficult to negotiate turns to the degree required to produce the sound. Sounds scary. Also, how long before the engine overheats?

timelessbeing wrote:It's the same left and right, but only while in motion.

So the sound is different left to right while sitting still?

Ya, difficult to steer but not impossible. It is not that hard to steer once your moving. You can damage your steering box without having p/s pump hooked up but that takes hundreds of kilometers of driving without it hooked up to happen. You are only going for a 2-3 minute drive.
I wouldn't drop the belt and hop onto the Lions Gate Bridge for instance, find a suitable piece of road where you can produce the sound without interfering with other traffic and then drop the belt and repeat your drive. With a half warm engine you will have 3-4 minutes to figure it out, tops.
Just be careful and pay attention to what your doing. Keep an eye on the run time and your temperature gauge. Keep in mind that the engine temperature will continue to rise after you shut it down, so give yourself some leeway, temperature wise.
Drag racing we would warm a cold bbc for about 10-12 minutes and then fire it up every couple of minutes for a couple of minutes so the heat can migrate through the block.
If your opponent was a a-hole he could burn you down on the start line. He would get a penalty and you would get a bi-run. It takes a while to seriously overheat an engine but it is still just a matter of minutes.

Peter

There is no sound while sitting still. The sound is not noticeable on city roads, but once you get on the highway it's obvious. It is the same in either direction, left or right.

You have to go fast which is what worries me. I'm going to need a really big empty parking lot to test this.

Just off the top of my head, the Tsawwassen ferry terminal causeway comes to mind.
It's a dead end highway with no sideroads to worry about and you will have a cool breeze off the ocean to help with the engine temperature.
If you get out there early or late enough you should be all by yourself and you can see oncoming traffic for a mile or two, easy.

That's too straight. I need to be turning and that's at least an hour away from me. I know some industrial areas and quarry roads around here I can try at night.