I've got a mysterious clunk going on underneath my Expedition. To this point I can't figure out whether it is in the drive train or maybe the suspension. It does seem to be coming from approximately the center of the vehicle. It's intermitant, but seems to happen more frequently when I am coming to a stop. It stopped for a couple of weeks and then came back recently. The truck has 56K miles and a 5.4L engine. I had the tranny fluid flushed out and replaced about 10K ago.

Any thoughts on what this could be?

 

I had this same thing on my 1999 Explorer. After about four trips back and forth with the dealer, it turned out to be the "Transmission Mounts". The bolts that hold the transmission to the body supports were loose. I had the clunking at start and stop and when going over RR tracks, etc.

The weird thing was that sometimes it would stop. I think it was after everything got hot and the metal expanded and made the bolts just a little bit tighter.

May not be your problem, but it could save you a few trips if they check that first. Good luck.

 

Thanks alot for your advice. I will give that a try tonight. The symptoms I am seeing seem similar to what you were experiencing.

 

check your spare tire. It may be loose. I had a clunking noise similiar to what you described and believe it or not it was just that simple.

 

Thanks, I'll give that a try. I checked my transmission mounting bolts and they seem to be tight. It would be nice if it was just the spare tire.

 

I checked the spare tire and it was in fact loose, however, after tightening it I still have the clunking problem. I'm glad the spare tire is tight now though. I really think the clunk is drive train related just from the feel of it. Something might be loose or worn, but I can't figure out what........the quest continues.

 

On my '98 the lower shock mount bolts on the rear shocks were slightly worn causing a very annoying clunk. To verify that this was the problem I wrapped the bolts with sheet metal tape and the noise has disappeared. Next step is to replace with new bolts. Might be worth checking out.
Dan

 

I just took our 99 in and the rear Torque bar was Making this noise. On take and on some turns this occured.Its very noticeable.The dealership just greased them.Good luck.

 

It sounds like the same clunk I have. I think it is a problem with the transferr case. If you rotate the front drive shaft slowly by hand (in 2 wheel drive) the drive shaft will turn freely, if you turn it quickly you feel resistance as if clutches are kicking in. I believe the clunk is the front drive shaft engaging as you accelerate. The faster you accelerate (0-10 mph) the louder the clunck, if you stab the trottle on ice or snow the clunck will be very loud (2 wheel drive). The problem will not happen in 4wd because the front drive shaft is locked in. I do not know how to fix it, but this may direct you a little. Look at your transferr case oil, I bet it comes out black with worn off clutch material. Good luck.

 

I have been having a simular problem with my 2001 Expedition. I have a clunking noise when taking off almost sounds like a flat tire. The truck also seems to jerk backwards. I have brought it in and they changed my shocks told me that was the problem. That was clearly not the problem as it happened again today. The shocks were changed 2 weeks ago. I had to change the transmission about 3 months after I bought it and now this. I also had to have the back glass changed b/c of faulty rear windshield wiper blade. Oh and I also had to have something done to the rear axle I believe it blew a gasket not sure about that but I had a flat and when they took the tire off the inside of the tire was full of axle grease and I heard them say something about a blown gasket. My Expedition has been a nightmare. I am so sorry that against my better judgement I bought a Ford.

 

Read my post it will help you out

Got a vibration?Read

 

Mine does it also, but it's 2WD, so the transfer case doesn't apply. It clunks when I'm slowing to a stop, usually when the tranny downshifts. It seems like driveline backlash. Don't know how to cure it, but it's annoying (sounds and feels like the transmission is falling out from under the truck when it does it).

 

 

kwb377, I think you are describing exactly what I am talking about? It's funny, it hasn't done it hardly at all in the past month. It does seem like some kind of backlash though, and seems to happen when the tranny downshifts when coming to a stop. My tranny is typically super smooth shifting though. Is your clunk fairly consistent? Could it be some kind of spline worn somewhere in the drive train?

 

SNIPER 222, I see from a different post you are from Waukesha, WI. So am I!!! Where did you take your Expy for the warped shaft in the transfer case, Griffin?. Did you have a clunking noise as I've described? I don't know that I have the vibration you describe.