Rumble identification driving me nuts!

FoxLakeTahoe · November 16, 2014

Hi all -

I've got a 2000 tahoe, 191xxx. I've been trying to track down a rumble for a while now, and need some new ideas - I haven't found a solution in the older threads - or from all the part swaps I've already done!

Rumble is most prominent between 3-12mph and 50 and up. From 3 to 12 it almost feels like a rumble strip - happens in drive, reverse, neutral, 2wd, 4wd, everything. When stuck in traffic yesterday, where the road leans over a bit to the right, I'd say it was louder.

From 50 on up, its more of a vibration - in drive, 3rd, tow/haul, and neutral.

The rumble isnt in the steering, brakes, or gas, more of in the seats/floorboards.

Both front wheel bearings are quiet when I rotate them - although I do get a little bit of bearing whine when driving and when the truck presses on them when the road is a little bouncy.

I replaced the front axles, no change in the problem.

Tie rods/ball joints are tight.

Swapping tires/rebalancing didn't correct the issues.

3 of the 4 ujoints have been replaced within the last year.

Driveshaft was just balanced - the vibration in the upper speeds "moved" a bit - less prominent at 70 and more noticable below 65.

Rear diff looked perfect to a shop that replaced a rear axle bearing, no change in the problem after that work.

I just swapped all of the brake calipers along with the other brake hardware, so there's nothing dragging.

I should note - 4lo is locking, but the truck isn't exactly grabbing in first. It does, however, grab in second when I put it in drive. 4hi is working fine in all gears.

Ideas? The truck is my driver between Pennsylvania and Michigan, so the last thing I want is something falling apart in the middle of Ohio! Thanks!

The Zip · November 16, 2014

FoxLakeTahoe - I have a 2001 Tahoe with under 130K miles, one of GM's best built trucks ever (my opinion). If I could take the technolgy in my 2015 Tahoe and place it in this one, I would be set.

You did a lot of work in an attempt to figure this out, which will pay dividends in the long run. But, trace your exhaust headers back to the tail pipe to see if some of the metal (pipe/cat converter/muffler) has slipped off a hinge or if a hinge is broken. You didn't mention if you felt the rumble during idle, so it sounds like some metal is hitting the chassis when the car is under load.

Based on what you've already done and the way you describe the rumble, metal hitting the chassis make sense.

ifixedit · November 16, 2014

Just my 2 cents worth but I have to ask: Are the front hub bearings the originals? If so, with 190,000+ miles I will guarantee you they are long overdue to be replaced. If there is one thing I have not enjoyed about my 03 is the damn front hub bearings lasting a whooping 80,000 miles or so and it's like a fricken timer goes off and sure enough they're due to be replaced. I'm on #2 on the drivers side (I'm sure due to be replaced shortly) and just did #3 on the passenger side this summer, it's a crap design and they are notorious for going out. If they are bad you will get the whining noise you describe mostly when cornering, they will also rumble like crazy just as you describe, the rumbling may even come and go as well. They will also fool you into thinking they are good by jacking up the front end and rotating them as the problem only shows up when the full weight of the truck is on them. Here's an easy way to tell if they are good or not: Jack up the front end and grab on to the tire and pull up and down on the top and bottom of the tire, if you get any rocking or looseness they are bad, same goes for pulling back and forth on the tire left and right, any play and they are junk. In any case, if you have not changed them in the time you've owned the truck, trust me one or both are bad and I'd just get it over with and do both.

FoxLakeTahoe · November 16, 2014

Thanks for the ideas guys -

I'll check out the exhaust in the morning. Theres no vibration at idle or when revving the motor in neutral or park - its only when the truck is rolling.

As far as the bearings go, one side has about 80,000 on it (second bearing on that side, and its right on time to go out), the other might have around 30,000 (third bearing). Last time I checked, they didn't have any vertical play when the truck was up - grabbed the top and bottom of the tires and tried rocking them back and forth. Yes, I've been curious if these things will make noise w/ load yet be completely quiet and tight in the air.

FoxLakeTahoe · November 16, 2014

Just checked the exhaust. The rear most hinge has a bit of horizontal play in it, but in wobbling the pipe around, I didn't notice it hitting anything - same goes for wobbling it around with the engine on. The rest of the exhaust was tight.

While taking sharper turns from 5-10mph, I don't notice any change in the rumble, which of course would be a tell tale sign of a wheel bearing. However, when leaving the rumble speed and accelerating up to 30, I can definitely hear what sounds like bearing hum. I should say that these are the only times when the wheel bearings suggest they're bad - theyre quiet and tight when the truck is in the air - but like what ifixedit said, they can certainly fool you as they may only make noise when they're loaded down.

ifixedit · November 16, 2014

It's sometimes tougher to tell if the bearing is bad rocking the tire vertically, as I mentioned above they will also fool you into thinking they are fine as I too have not had any make any kind of noise by rotating the tire when the front is off the ground. If you've got any play rocking it side to side left and right (you'll be able to feel it), it's bad, there should be zero play. Another way to tell is when you hit the brakes if the truck pulls to one side or the other. When the second of my front hub bearings on the drivers side got bad it would rumble for 2 miles going anywhere from about 40 MPH and up, then it would quit for a few and then come back and so on, slamming on the breaks for some reason would make it stop for a few minutes. About a week after it started this it got so bad and noisy one night on the way home that I was worried it was going to completely lock up on me at 65 MPH on the freeway! I proceeded to jack up the front end when I got home, rocked the tire back and forth side to side an sure enough there was some considerable play. When I replaced the hub / bearing assembly the following night I could clearly see the seal had gone out, water got in and it was pretty badly rusted, it was a disaster just waiting to happen if I hadn't gotten to it right away. If you have 80,000 rounds on one side, it's due, the built in timer has went off.

BTW: If you replace it yourself, when you go to get the new hub / bearing assembly the auto parts place will likely offer you the standard made "overseas" replacement and the better replacement, I've tried both and they seem to last about the same. One thing I've learned that helps them last longer is when you corner into a driveway where there's a curb or so on, take it easy and go up them slowly while the wheels are turned so the bearing doesn't get wracked on the way up and over the bump. I honestly think I took out my first hub bearing doing this as I had turned into a friends driveway with a pretty heavy curb going too fast and the truck kind of felt like the front got jammed as I went up and over the bump, a couple days later and the bearing was making whining noises and a couple weeks later was on it's way out.