Hi guys. I'm new to this forum, so please excuse me if I post this question incorrectly. I have a 1999 F-150 SCAB and I've got a noise going on below the cab and towardds the rear that has been driving me crazy. I've taken it into the Ford garage and also my independent garage...neither could find anything. The service guys would go with me for a ride and they would "hear" the noise, but couldn't explain it. The noise "only" occurs going over bumps, uneven surfaces on the roads. More of a clunking sound. I've checked for loose shock mounts, loose exhaust hangers, most suspension parts in the rear, that I'm able to access under the truck while lying on a creeper. I'm wondering if it might be the spare tire hanger? The spare is in place. Any of you folks out here in Fordland have any similar noise emitting from under and to the rear of their F-150?

Thanks for any and all help.

Jerry C.

 

i have the same thing, a clunking noise somewhere in the drivetrain. Maybe something in the transfer case?

 

Toxic Bob,

Sheesh, I certainly hope it's not the transfer case. Sounds really like it's coming more from the rear of the truck. Nothing has fallen off yet, however when this noise began, it didn't occur as often as it does now. I figured I'd wait until something fell off and then decide if tht was what my noise was.

 

I experienced something similar to what you described for a few weeks last year until I was able to solve the mystery. First, try to determine if the clunk seems louder and more frequent during cold weather. If so, I may have your answer.

My problem turned out to be a combination of the rear muffler hanger arm and the rubber hangers themselves. Try bending the hanger arm further up and out away from the frame so the muffler can’t swing around as much. There’s not much you can do about the rubber hangers themselves, but they do make a lot of clunking noises when cold. All you can do is try to minimize it. It’s amazing how a noise can seem to come from one place when in fact it is really coming from somewhere else.

I can never completely get rid of the noise in the winter, but it’s completely silent during the warmer months. At least I know it’s not a safety issue, just a minor annoyance.

 

Rikster, sorryy for the llate reply. I'
ve checked the exhaust/muffler hangers...they all are fine. The "clunking" noise I have is there all (4) seasons. I've more or less decided that I'll wait till "whatever" falls off. You are correct though in the travel of sound. My garage mechanic went out on the road with me and he swears the noise was coming from right below him...once up on the rack, he discovered that the clips that hold the brake pads in were are the "worn" side, so he replaced those....I still had the "clunk" after leaving the shop. We're supposed to have some "warm" weather here on Sunday in Green Bay, WI. I think I'll lower that darn spare tire and see if something is loose there. Thanks for the reply and the help.

 

check the little black plastic discs inbetween the leafs they wear out sometimes another thing to check is your parking brake cables see if the rubber is worn through anywhere down to the metal. ussually at the point it is closest to the leaf springs.

 

Just a thought:
Did you or your mechanic check the U-joints in the driveshaft near the rear-end? If they are going you'd hear clunking more often then just when you go over bumps though....
Also, if you have your spare tire mounted under the rear of the truck bed, is everything tight with that?

 

Dunno if this will help but there was a thread a while back on a noise insulator between the bed and frame that was prone to falling out, somewhere in the vicinity of over the rear wheels.

 

Check your U joints

 

Loose parts in the rear brakes?

How about some rocks lodged up in the spare that are boucing around on the steel of the spare rim?

Get a couple of people to jump up and down in unison in your pickup's bed and see if you get the noise. If so get underneath with safety glasses and try to find it. VW's are notorious for losing the front brake pad retaining springs, once gone the pads rattle like crazy as the tire goes over bumps.

 

A friend of mine had a similar problem that you could feel more than you could hear. The final determination (by Ford) was "over tightened body mounts." I believe there is a TSB out on it. Have your dealer check into this one because it is not visible and hard to trace for that reason.