Sometimes when accelerating (regularly, not hard) I get a thump thump sound coming from what I believe to be the rear end. I can feel it too. The sound is similar to what you would hear when driving thru a pothole at 30 MPH. Anyone know what this is? It can't be good.



Thanks,
mikebaby

 

is it while your already moving ? or when starting from idle ( red light, stop signs, ect.. ) the start from stop scenario could be the dreaded clutch pack problem. ( just had mine fixed yesterday problem seems to be gone ) check out the other drivetrain forum for more threads from folks with the pings,pangs,clunks and thumps...... good luck ....

'04 f-150 xlt 4x4
reg. cab flareside
drk toreador red

https://www.f150online.com/galleries....cfm?gnum=4362

 

I only notice it when I'm already moving, but it's always happens right after I've been stopped. at about 15-20 MPH I'd guess.

mikebaby

 

Am I the only one to experience this?

mikebaby

 

No your not. It happens on mine the same way maybe about once a month. I'm going to see if it get worst so that I can show the service dept. what it's doing. I have the 3.55 back end.

 

Please keep us advised I have the same clunk
Gatr

 

You got a body in the bed, mikebaby??

Just kidding, sorry I can't help you.

 

Is it just the thump thump sound by itself or do you feel the truck jerk when you hear the thumps?

 

I don't know if I would say I feel the truck jerk, but I do feel the thump thump, whatever it is.

 

I feel it. It's like it's something is slipping.

 

I get an occasional thump sound when backing out of my driveway. Sounds like it comes from the right rear. It's usually where the slope of my driveway and the street meet. Haven't figured out what it is, but never when I'm driving forward.

 

I heard it again on my way home tonight. I think it's more of a clunk clunk than a thump thump.

any ideas?
mikebaby

 

Check the spare tire and make sure it’s not loose.