Langeb75

What bearing, Axle? Where u hearing any constant noise or was it very intermittent? Mine is silent until the dreaded binding noise.

redhawk427

This bearing

a7mgte

Well, I've got some really bad news...it's just gonna get worse and worse. The only reasonable thing to do at this point is too just give up and sell it to me before it falls completely apart on you. Hey, the next 4-500,000 miles go by quick man...get out of it while you can.

If that's not an option for you then...How do the bushings look in your springs / shackles; Are they really loose at all? Is your spare tire cranked up nice and tight? Check your gap guards, and the one behind the rear bumper, if one is loose it could be just flapping around when the wind blows on it just right. Your rig looks like the rear wiper reservoir may still be in tact, is it hanging up like it should be / unable to bounce off the rear quarter panel? The rear wiper itself have room to wiggle around in the wind? You extended the E-brake cable when you did the lift? Could it be tapping on the gas tank or frame? Best not to have it set when checking this. (No, not trying to kill ya...but it when set it has a lot of tension on it that's not there when going down the road. This also may explain the change in sound, full tank vs. 1/2 tank, know what I mean?)

Basically if your satisfied it isn't a drive train noise, then just go around back there and push, pull, wiggle, and tap on anything and everything you can get your fingers too, inside and out. Also check the bottom of the storage compartments in the back, a random bolt or something bouncing around in there can drive a guy nuts.

If that fails to yield anything, then I'm afraid you're just gonna have to settle for my first option.

Langeb75

a7mgte I will have this 4runner till the day I die! My springs are brand new from Skyjacker and the other bushings were inspected before putting the lift on it and determined to be in great shape. In regards to the flaps I have taken them all off. The spare tire and all of its components, GONE. I have a spare in the back now securely tightened down. There is nothing back there. I tightened every bolt - nut - and everything in between. When I went on my 270 trip to get my new puppy it did it only about 6-7 times which was an improvement over the other times.

I hear ya about the wigglin around in the wind stuff but man this doesn't sound like something just tapping the body from underneath but a serious grinding noise. I checked all my compartments and took a lot of stuff out, jack and accessories. the resevoir is on its perch.

WTF is making me go this crazy.

Langeb75

Noise was really bad drivin back from my hometown this morning. Grinding bad bad bad.

Langeb75

My theory, please tell me what you think. I seems to do it more when I have weight in the back end. When I was driving home with my buddy in the back seat it did it a whole lot worse than when it is just me. As it did it a whole lot more and worse with him back there I could hear the noise kinda shift from the left rear to the right rear. When we did the 4 inch lift springs we didn't adjust the rear proportioning rod, I hope that is what it is called, so do you think that my brakes could be doing something funny without this being compensated for the lift? Also it only does it at highway speeds so I am thinking the wind at those speeds are pushing my rear end down a scosh causing these fun grinding noises.

a7mgte

I would find a shop that has a dyno. Then you can load the rear and walk around the truck listening for your mystery noise while its "at speed." It shouldn't cost too much, and for another few bucks you might as well do a couple pulls while its there so you know what that baby's really got.

Probably your best bet short of some brave soul leaning over the open tail gate while driving down the road at highway speeds.

Teuf

Is the muffler touching the frame or body anywhere when under load? I know how can you tell?, wear spots?

Langeb75

Update, Teuf I checked the muffler and underbody for places of noticeable rubbing and found none. I shacked and pushed and pulled the muffler and couldn't see where it would hit the body. I put an extension on the LSVP and to my behold, still doing it. I just don't get it. Can bearing not make a sound, drive great, and then make a crazy grinding noise? Should I replace my shoes? When I took my drums off to look for broken springs or anything noticeable out of wack I didn't come across anything.

Langeb75

I had a mechanic ride with me and jump up and down in the back while driving down the highway and it did it frequently when he did. He thinks it is the rear shackle, can these just go bad? It looks ok. I have new bushings on the leafs from Skyjacker at the shackle. If so should I find someone to take the entire shackle off and weld new ones on?

badattitude

I had a similar noise on a GMC Jimmy. I won't tell you how much money I spent trying to fix it. But I will say I'm not kidding, it was a dried out walnut trapped on the top of the gas tank. At the right speed, in the right wind it would rattle. I was sure it was the cat coverter. It almost drove me crazy. Check for loose stuff like mgte said, including non factory items you may have picked up. GOOD LUCK

a7mgte

If it were in the shackle assembly it would make the same sound while bouncing the truck when it's parked in your driveway.

The shackle itself can't really go bad unless it was to rust so badly it broke in half somehow, since they only consist of a couple steel plates and a pair of bolts. None of which should be welded on anywhere, unless your running some kind of exotic shackle mount, even then I've never heard of the shackle being welded at all. Although I guess the factory shackles are welded to the bolts on one side, I don't know how much good it does other than making installation tougher. The bushings can and do fail though. You have new ones in the springs; did you replace the ones on the frame?

Langeb75

When I mention welding the bracket to the frame I mean the bracket is already welded from the factory to the frame so I was going to take those off and weld new shackles on. In regards to the bushings no I didn't replace the top bushings only the bushings that came with the new leafs. The guy who did the lift said those bushings looked great. Can a shock make a crazy noise?

Langeb75

Have you ever seen a defective Leaf Spring Assembly? This is an aftermarket Skyjacker assembly with a 4 inch lift to it.

Langeb75

So two years later to the date it seems I was packing up our kayaks and camping gear when I notice my mud flaps had some chunks out of it. Yes it was still making the noise on our three hour trip up north in Michigan. I pulled my tools out, took off my mud flaps and holy crap no more rear end grinding noise. The weight of our camping gear made the truck sit at the perfect level for the mud flaps to catch on my meaty Mickey Thompsons and cause the noise. What sucks was my wife made the suggestion two years ago that they may be the problem. I thought no way mud flaps could be making the crazy noise like that. Should have listened to her two years ago. Thanks everyone for making suggestion a couple years ago for I wanted to shed some light on this subject and finally put it to rest.