Grinding from rear end!

huntb · **Posted:** Mon Mar 25, 2013 10:36 am

This just started happening yesterday, which is the day after I put my sway bar back on for the first time since I put my lift on. It seems to only happen at lower speeds and I definitely noticed it today coming to a stop after exiting the freeway. It sounds like a grinding noise or what might sounds like a squeaky bushing if the noise were more constant.

The reason that I mentioned my sway bar is because after the lift and before I put the sway bar back on there was a definite clunk while going over small bumps in the road at slower speeds (10-35mph) that now I think may be play in the driveshaft or a bad transmission mount. The clunk is still there but doesn't seem AS bad. Now that the sway bar is back on I am wondering if that could be effecting the grinding noise? I guess I'll pull off the sway bar off at lunch and see if it goes away... Anyone have any other ideas besides maybe pulling the driveshaft and driving it in 4wd to see if the noise goes away? I don't wanna mess up the front diff going this route...

tommudd · **Posted:** Mon Mar 25, 2013 11:13 am

You can pull the front driveshaft with no problems and just drive it like you would normally
Sway bar would have nothing to do with grinding noise
check for things in the rotor possibly like a small rock etc

huntb · **Posted:** Mon Mar 25, 2013 11:19 am

tommudd wrote:

You can pull the front driveshaft with no problems and just drive it like you would normally
Sway bar would have nothing to do with grinding noise
check for things in the rotor possibly like a small rock etc

Thanks tommudd. What do you think of pulling the rear DS?

Gageraid · **Posted:** Mon Mar 25, 2013 12:12 pm

See what happens when you put it in reverse. When I had a rock in my rear rotor (don't ask), it only would only make a noise in reverse.

huntb · **Posted:** Mon Mar 25, 2013 1:21 pm

K update... I drove it home on lunch (about 10 min drive, half highway) and as I was getting into my neighborhood it did it once as I took a right turn and then a few times while I was on my street when I would pump the gas.

On lunch I removed the rear sway bar (honestly it sounded almost like a bad bushing might sound). Then on the way back to work it did it again at the exact same spot as it did when I was on my way to work, this morning on the off ramp of the exit I take, when coming to a stop (the off ramp goes up to an overpass). Then it did it several times as I was going over the overpass and after I came down the hill from the overpass I couldn't get it to happen again the rest of the way to work (maybe a half mile). I'm just stumped...

Gageraid · **Posted:** Mon Mar 25, 2013 1:42 pm

How does it seem to act when you go over a speed bump or something that allows for flex? I would find an open parking lot and try going in circles at full lock.

lfhoward · **Posted:** Mon Mar 25, 2013 1:53 pm

huntb, I had a clunk in the rear after installing my lift too. I had it checked by a 4x4 shop and they said that the new adjustable trac bar (JBA) uses Heim joints rather than bushings like the stock trac bar. This allows better flex and articulation but can be noisy over bumps (especially speed humps). The 4x4 shop said everything looked good and there was no safety issue. So, I don't know if you have a JBA adjustable trac bar, and a clunk isn't the same as a grinding noise, but I thought I'd throw that out there in case it helps.

huntb · **Posted:** Mon Mar 25, 2013 1:56 pm

Over small bumps at lower speeds there is a definite clunking from the rear end. I took it in a few weeks ago and had the mech look it over thinking it was a bad bushing in the rear (he didn't find anything and thought maybe it was just the bumper cover banging) but now I can't help to think that maybe it has something to do with the driveline.

Last time I went over a speed bump it sounded like my springs bound up because I haven't installed my extra bump stops for the rear yet. Maybe it wasn't the springs that made the clunking noise?

Edit: I have the stock trac bar tho

TurboGoKart · **Posted:** Mon Mar 25, 2013 7:35 pm

Take your wheels off, then take the brake pads out and look at them. Look at the rotors while you're doing that too. Usually a grinding sound on braking is terrible rotors and/or brake pads at the end of their life.

Diggerfreek · **Posted:** Mon Mar 25, 2013 11:31 pm

Any gas tank skid / drive shaft contact indicators?

Bmxer524 · **Posted:** Tue Mar 26, 2013 2:34 am

I doubt it's a rock as Gageraid suggested, I've had that happen twice now. Once i was stumped it would only happen when riding. Pulled over after 100ft or so of driving to figure that out, heard it again, did a u-turn to stop under a light to see and the brakes broke the rock and i was able to get it out lol. Don't get me wrong it can't hurt to check, literally takes less than 5 minutes. Don't even have to take a wheel off lol.

Anyways, like Digger said look at the gas tank skid and driveshaft to see if contact is made. I know lifted KKs tend to hit the skid especially when they flex.

Ted15 · **Posted:** Tue Mar 26, 2013 5:57 am

Rocks can also get inside the rotor where the shoes for the parking brakes are. Mine got filled with tiny pebbles from the mud I got stuck in once. It drove me crazy trying to find where the noise was coming from. Mine was more of a shriek but it started off with a grinding noise.

Smetna · **Joined:** Mon May 28, 2012 2:43 pm **Posts:** 50

Could this be an anti-Lock brake/ stability control malfunction caused by the lift? Maybe a sensor came loose?

huntb · **Posted:** Tue Mar 26, 2013 8:45 am

I just don't know if this could be the brakes because it happens normally when I am not hitting the brakes. Like I mentioned earlier once it starts, I can get it to happen again by pumping the accelerator. I will definitely be checking the brakes, and Digger good suggestion but I don't have a gas tank skid (yet). I just see myself popping open the diff in the very near future. The knocking sound that I have been hearing seems to have gotten progressively worse since I first noticed it after the lift install. I just hope its not play in the pinion

Bmxer524 · **Posted:** Tue Mar 26, 2013 12:00 pm

The gas tank skid isn't much different than what comes factory on the gas tank(for those without the skid plate group). So it can't hurt to crawl under and look. You would probably see something on the tank plate or the driveshaft.

Grinding from rear end!

Who is online