Bad car noises!

[kelvin]

OK, so i tried a search, but my problem was too vague to get any specific threads...

I've got a lifted '99 with 115000 miles and 185/75/r16 tires (not big)

I hear a grinding noise when i'm at speed on the freeway AND let off the gas. it has kinda the same feeling/sound as if i took the pads off my breaks and just let the caliper rub the rotor. but just a shade harder to hear because its coming from under the car more. when i'm driving around town it doesn't happen. so it probably is initiated by either the speed, or the 4th gear....

I have several theories: transmission is shot, bad clutch, (suggested) bad water pump bearings, drive shaft/joint noise from the lift (about 2 months ago), diff noise.... Any of these sound right? the sound is horrible and i dont want to break anything further.... Please tell me it sounds like something cheap.....

[Scott Harness]

It's the driveshaft vibrating. The lift puts it at weird angle. I think everybody's does it, mine does.It doesn't seem to hurt anything,maybe in the long term it might?!!?

[nfpgasmask]

I would say it is probably due to your lift. Everyone on here who has lifted said they get similar noises at speed...I'm sure someone will chime in with their experiences, as I myself do not have a lift....

Bart

OK, so i tried a search, but my problem was too vague to get any specific threads...

I've got a lifted '99 with 115000 miles and 185/75/r16 tires (not big)

I hear a grinding noise when i'm at speed on the freeway AND let off the gas. it has kinda the same feeling/sound as if i took the pads off my breaks and just let the caliper rub the rotor. but just a shade harder to hear because its coming from under the car more. when i'm driving around town it doesn't happen. so it probably is initiated by either the speed, or the 4th gear....

I have several theories: transmission is shot, bad clutch, (suggested) bad water pump bearings, drive shaft/joint noise from the lift (about 2 months ago), diff noise.... Any of these sound right? the sound is horrible and i dont want to break anything further.... Please tell me it sounds like something cheap.....

[kelvin]

I hope you guys are right... keep the theories coming!

I should be able to just swap the springs back out and it would go away, if thats right.... easy test... why has it waited this long to make noise? and why only when i take my foot off the gas at fwy speeds?

thanks!

[Ascinder]

I get a slight hum/vibe only when I let off the gas at freeway speeds. It seems to only happen when the VX is coasting. If I keep even just the smallest bit of gas applied it never seems to occur except when I decelerate when approaching an offramp. I have been wondering if any other 4x4 vehicles experience this and if maybe a knowledgeable driveline shop would have any advice on what to do to fix or if it is even truly a substantial problem at all and not just a minor annoyance? Another question that has been floating around my head for awhile now is: Who has had their lift the longest and experiences this phenomenon. From half substantiated rumors, this vibration is nothing to worry about, but I'd like to know somewhat more certainly that someone had driven umpteen thousand miles with this happening and their has been no unusual problems as a result.

[kelvin]

it does sound more like a grinding than a vibration....

[yal^]

My vx was lifted in 2004. I drove with similar grinding noise ever since.
This year in January I grenaded my front diff. The spider gears blew and turned the whole diff into a rattle. It happened while I was climbing a really steep wall. I just took my front wheels over the ledge giving it some gas and landed really hard. Diff blew and I lost front drive.

Needless to say I got the front diff replaced, and since my friends had the front in pieces already they installed locker and front hubs.
In essence the front wheels are now disconnected for pavement driving and I have not heard the noise again.

This should narrow your quest for the grinding noise. Front driveshaft is still connected but its quiet.

After replacing the front diff I was wandering if there is an actual issue with spider gears that we do not know about and that is not detectable until the vx gets lifted...

With the locker the front wheels do not pull while on pavement. When the hubs are locked in 4x4 position there is no way of driving in high speeds so there is no way to say if new diff would be making that noise too.

I do feel like I killed two birds with one stone though. Maybe even three.
1. I got the front diff replaced that may have been faulty before it blew anyway...
2. I got the locker installed which makes my truck 2-wheel drive and the entire truck got much quieter while on the pavement.
3. Even though there has been a discussion about disconnecting the front wheel drive and that it doesn't affect the gas mileage, trust me on this, mine improved. I drove to Moab this year from Chicago. In comparesment to the last year the mileage was more efficient, not to mention the ride was more comfortable.
4. Most importantly the off road performance has changed; with locker and hubs I tackled more interesting trails this year.

I could go into a couple of other benefits but I have no idea how much you are into 4x4 performance. We lift vx's for looks and for off-road performance.

Let me know if you need more info.
Good luck.

k

[2K1 1K2]

hi. not sure that this may help but...

have you tried the air pressure on your tires? all matching?

the old set of tires (stock) started making a rubbing sound, once they started to wear. upon installation of new tires, she acted/sounded as good as new.

-jose

[Ascinder]

I have locking hubs in mine too, and oddly enough I have never run with them unlocked in 2wd mode. I will unlock them today and report back if there was any difference at all like you say. If its that simple, then many people can have piece of mind for the low cost of a simple set of hubs.

[Joe Isuzu]

I also have a noticeable hum when I lift off the gas at highway speeds, my VX isn't lifted either, honestly, I always assumed it was just the tires, maybe when torque is applied to them they make less noise?
anyway, I wanted to reassure people it's not a lift issue, at least with respect to the hum/moan/increased road roar when lifting on the throttle

[Ascinder]

I tested out and confirmed today what Yal^ said earlier. If you get lockable hubs and install them(seriously takes under 15 minutes) and unlock them it goes away completely. The only thing is you lose a lot of power up front. The TOD is still trying in vain to shift your power split, but is obviously now just spinning your CV's and not your wheels which translates to power being robbed from the rear. I was happy the sound went away for me, but hated driving this way, so the sound stays. The lockable hubs are about $50-60 usually on ebay. You can also buy new ones for around $100, depending on what you get. i think the consensus is that the AISINs are indestructible but very pricey new(rebuilt not bad) and the WARNS are a close second. There are also some other brands out there that will do the job, but I can't make any claims for them.

[yal^]

I am a little confused... you have hubs installed but no locker?

[Ascinder]

Well, that's a funny story actually. I have a locker that I bought with full intention of installing, yet when I had everything all apart I chickened out and never put it in(the VX had been down about a month at that point ). It is still sitting brand new in the box waiting for a home. I was actually waiting for some 4.77 gears for the differentials that never materialized. I installed the hubs anyways since I had to reinstall everything still and they were just as easy to put in as putting the original solid hubs back in. I have since changed plans and am actually seriously looking at the SAS now. I know everyone says that, but if the job I am waiting for comes through, I think I may just be the first person to actually pull it off. We'll see. Also if anyone out there is interested in a brand new Aussie locker for the corporate 10 bolt differential(your front end) I have one to get rid of.