I have a 2010 F-150 Raptor with ~50k miles and stock rear suspension. I am getting a thump / clunk when going over small / medium sized sharp bumps. It sounds like someone is kicking the bottom of the cab behind the rear seat. I also get a suspension groan, coming from the back, when the rear axle articulates.
The sound is not vehicle or engine speed dependant and only happens when going over bumps or angles.
Here is what I have looked at:
- Shocks: I replaced all 4 shocks with rebuilt units
- Transmission mount: I put a jack under the t-case and lifted, no separation at the mount
- Bed: nothing in the bed and all bed bolts verfied tight
- Spare tire: verfied spare tire tight and in place
- Rear diff: pulled the axle shafts and did not see any unusual wear in either the bearing surface of the shaft or the bearings themselves, bearings ran smooth, fluid was clear with no particulates
- Rear suspension bushings: I took a pry bar and checked for vertical and sideways play and didn't see anything concerning
- Driveshaft: no detectable play in joints and no vibrations while driving
I also paid a shop to look at it and they punted and told me to take it to a spring and chassis shop, but the recommended shop creates logistics issues due to distance and dealing with Houston traffic.
This is driving me nuts. Any ideas on where I should look next?
Firstly, awesome truck! Secondly, are you playing in the dirt with it? I think leaf springs can get noisy when you get dirt between the leaves. Also, have you tried lubing your driveshaft? Dry spines on the sliding part can bind and make the rear suspension do weird stuff. Worst case, your u-joints and splines get new grease and the noise persists.
Also check your exhaust hangers. Those pipes make all kinds of racket if they bang around.
Long shot but a large number or Raptors had driveline clunk from the driveshafts. I would check the linkages really closely. Might be the shaft moving in and out of the rear axle.
I forgot to mention that I have lubed the driveshaft slip yoke with the recommended special Ford Smurf grease.
KaiserM715 said:
I forgot to mention that I have lubed the driveshaft slip yoke with the recommended special Ford Smurf grease.
Good. I would attack the leaf springs next. Its not hard to break them down and grease the E36 M3 out of them. THere are a number of companies locally that do it in the 150-200$ range around here.
I'll look into lubing the springs.
In reply to stylngle2003 :
It didn't come with one.
After some further digging and investigation, I am looking into wheel bearings. I have stumbled across a couple of other trucks with similar symptoms and that was the issue. I measured 0.010" radial play at the wheel flange. I haven't been able to find any specs for either radial or axial play (the factory service manual doesn't include either spec, oddly enough). The noise (clunk / clang) is 100% repeatable when I shake the back end of the truck from side to side (some of which I have learned is normal for a c-clip axle). I have pulled the axle shafts and the running surface looks good and measures the same across the entire surface on both shafts. Comparing the spec ID of the bearing to the measured OD of the axle shaft, there should be a lot less than 0.010" play. I will look into it further at the end of next week.
I have found replacement parts for everything I think I need, except for the rubber o-ring that is in between the c-clip and the button end of the axle shaft. I can't even find a part number from Ford.
