Can't figure out what this noise is

Hi everyone, I'm new to this forum so I apologize if this issue has been brought up before. I recently purchased a 96 blazer. Turns out, it had several things wrong that needed to be repaired immediately. It was shifting into 4wd while I was driving. Got that fixed. It was and still is making this rubbing or grinding noise that i thought was associated with the 4wd shifting automatically. And it makes the noise as I'm driving so I feel like it may be something wrong that spins. But since I got the 4wd issue resolved, it has to be something other than that. Does anyone have any idea what this rubbing or grinding noise is as I drive? It increases as I accelerate. It's pretty annoying and I'd like to know if anyone has had this problem before. Your help is greatly appreciated.

CV joint going bad maybe?.. thats just an idea.. could be a few other things too that make have to do with the axel...
did the previous owner tell u if it was wreckd at all??

No, he claimed the noise was from it being in 4wd. And the reason I believed that was b/c when he pushed the 2wd button, the noise would go away for a little bit. I'm told it could also be the bearings? Any thought on that. Thanks for your input.

Welcome

Does the noise go away when you put the tranny in nuetral while cruising?
Does the noise go away when you put on the brakes?
Does the noise go away when you trun one direction or the other?
Does the noise go away if you see-saw the steering wheel back and forth?
Does the noise go away of get louder in any combination of the above?

I should also mention that it creates a vibration feeling, the truck doesn't shake or anything but I can feel the vibration from the grinding or rubbing on my feet as I drive. The noise is only there when I'm driving. So as I slow down or turn, the grinding and vibrating gets slower. I don't believe it exists when I'm in nuetral but I have to check again to make sure. I haven't tried seesawing the steering wheel so I'll give that a shot too.

Jack it up. One wheel at a time. Check all brakes and bearings for noise.

Do not drive this vehicle till this is identified.

Could be gear box but I'd be thinking that if its not bearings or brake problems, then it is a U joint of sorts. Could well be in the front cv joints also. With the modern automatic tranny systems the engine basically does not brake through the tranny. So when you let of the gas, the sound could well change and/or get better.

I am BY NO MEANS an expert on 4 w drive.

quote:

I should also mention that it creates a vibration feeling, the truck doesn't shake or anything but I can feel the vibration from the grinding or rubbing on my feet as I drive. The noise is only there when I'm driving. So as I slow down or turn, the grinding and vibrating gets slower.

this most likely isn't your problem, but i figured i'd mention it anyway: my rusty old '88 blazer was doing what you describe, the problem was that the front mounting points where the body attaches to the lower frame had rusted through and the body was resting on the transmission.

You need to identify if the noise is related to the tranny or not. By getting up to speed, 50 or so on an open road with no traffic. Shift the tranny into nuetral and see if the noise goes away. If the noise is still there, then I would suspect wheel bearings or brakes, and maybe a CV joint. The easy check on the cv joint is if the boot has broken open. If it still sealed, unusual for them to go bad. Sure sign the boot ahs broken open is grease all over the place.

The grinding could be a bad wheel bearing. Fortunately they aren't bad to replace, unfortunatley they are not cheap.

Now the grinding could be that the brakes are so far gone that you have what is left of a pad rubbing on the rotor. In that case the simple check is to run your finger nail over both sides of all four rotors, If the nail gets hung up in a multiple grooves, you need to check the pad.

Either way, find an alignment shop and get a free front end inspection. They will tell what is rubbing and should give you an estimate on repairs. If you want to fix it yourself, we can walk you through it. Usually the labor costs you save is more then enough to buy the tools you need to do the job. The bonus is you have the tools for the next time, or for other things, and you get to bond with your truck.

I really appreciate the info. I'm going to get it checked out, and I think I'd feel more comfortable taking it to my mechanic to fix. Thanks. And when you say they are not cheap, can you give me a range so I know what to expect if that is the problem?

I just did a whole front hub on a two wheel drive for 30-35 dollars, in parts. Four wheel drive is certainly much higher even if just parts. On a 2 wheel drive model the front spindle can be damaged easily by an outer bearing running too long when bad. Even used, they go from 40-65 dollars. A 4 wheel drive has axles and much more serious parts, but I'll let the experts tell you the bad news. Having a much more complicated situation makes it expensive. The rest of the problem is the same, if the bearing is already burned out and you continue to drive, you will increase the cost of the repair MULTIFOLD because the surfaces that the bearing-hub work WITH will self destruct also. Not only costing you three times as much but also endangering your life.

Learned somnething the hard way while driving fast with a bad set of drum brakes when still a teen. Hit the brakes and I SURELY STOPPED. Kinda funny at the time. The left front drum rolled out from under the car and into my view. It was in three seperate rings and rolling in three seperate directions. Luckily I was on a back/dirt road. Would not have been good at nite with them revenouers behind me though

I dont really believe in four wheel drive for regular use and I have lived in a dozen different snow states or countries. The parts and maintanance cost on them are for those who like mudbogging and rock-crawling. Not for going to work or groceries. I have found myself often pulling out four wheel drives out with my chain wheeled two wheel drive. Have NEVER been resqued by one of them. Was never a need. Its very, very odd the amount of confidence that a four wheel drive vehicle gives its driver. This confidence is often misleading and shouldnt even exist. Leads to having problems that shouldnt happen.

Dont know if I would ever drive a vehicle at 50 mph if I already had a noise, call me conservative?? Have certainly driven 150 or better and then had it start making noise, but not before.

Even went faster while it blew sky high, but it hard to pull your foot up that fast too.

I just had both front hubs replaced and the idler arm for about $600 at a mechanic. Now I'm chasing new pops.

4wd is useful in areas that get a lot of snow, but don't allow the use of chains and studs on public roads.

Too bad about the big bucks but thats what 4 wheeling is all about. I would bet that you got a pretty good deal price wise in. BOTH front hubs?

If I had had to replace the whole hub/disc and also the spindle and bought new parts it would have cost me about half that for just one wheel. I just got lucky. Lucky it was only a two wheel drive. Lucky I know how to do all the work myself.

This week alone I would have spent about 250 for someone else to do that (cause they would have ripped me off for a spindle) and also replaced a tranny in one worth about 300 used plus labor. Thats about a 700 dollar job for 100 in donor car parts. So being cripple and retired and not having any money to pay for it just made me about 950-1000 I didnt spend.

I am very glad you got it fixed and I wont worry about your driving a dangerous car anymore.

I know mine may pop now. But it's never been stuck. Except for, before I hit that button on the dash that says 4x4! You just need to always be aware of the limits.

Hub assemblies for a 4wdr run about $170 each. That is the part alone, and comes with a new ABS sensor, install the new sensor. It comes with the hub for a reason.

Bigbrett,
Pekin eh?
High neighbor. I am over in EP. You into 4wheeling?