Yeah, I think there would be a subtle giggle coming from the FORD offices.

RP

 

hey rock,

in a continuing effort to try and figure out why my truck is thunking...i decided to try something tonight. if my memory serves me right, i really didn't start noticing the thunk until this past spring. i bought my truck in october last year and then promptly put nearly 400 lbs of sand bags in the bed for winter driving.

tonight i put the sandbags in the box and went about with my normal driving stuff. what i've noticed is that the thunk is much more subdued, and often times not occurring at all. keep in mind my truck normally thunks at nearly each and every stop. so, i'm not really sure what to make of this. is the change in driveline tilt/angle causing the relaxation of the problem. or is the rear axle wrap somehow lessened due to the extra weight?

guess i'll have to mention this to the service manager next time i take the truck in...

troy

 

Interesting observation. I'd definately mention that to the service manager (or even better, the mechanic that's going to be dealing with your truck).

Let me know.


RP

 

Hey Troy and Rocky Peak,

If I didn't have to work at my regular Engineering job, I could fix all the issues with our trucks...Unfortunately I don't think I could make much of a living fixing issues with F150s since most everyone is looking for a free answer...Oh well, back to work designing Fork Lifts. *Opportunity light just went off* Make it an after hours endeavor??? Hmmm, would need some help though. Any thoughts???

Later,

~DM~

 

That's kind of how I found mine... loaded up a load of lumber in the bed (about 600 lbs worth) and it was gone. As soon as it was unloaded, it was back. That's what led me to the suspension. After connecting the electronic ears to the truck, they determined it was a spring in the spring pack shifting. Replaced both rear spring packs and it never made the noise again.

-Joe-

 

joe,

my truck doesn't make a noise...it just thunks. a thunk i can feel but have never heard...at times it actually feels like someone tapped my rear bumper from behind.

troy

 

Troy and I, undoubtedly, have the same thunk. I've looked in my my rear view mirror several times thinking.. "*****! THEY HIT ME..." only to realize that it was the thunk.

I'm tempted to go find some weight and haul it around for a day and see if I can make some correlation with that. Did you all see the post about the broken weld on the SCREW forum? I plan on looking at that weld on my truck when I get back (stuck in South Dakota til Friday).

Any other thoughts?

--

Dave... if I was your neighbor, I'd be there in a heartbeat to start the 'troubleshooting venture' but, being in KY... it's tough. Also, like you, I have this other thing called a job that requires numerous hours. Unlike you, I'm not fencing in the state of North Carolina but, none-the-less, I definately agree, I don't think there's a slew of $ to be made in troubleshooting the infamous problems. Good luck if you dive into this. I'm interested in that 'freebie' that you mentioned. LOL

RP

 

hey guys my 4 x 2 had the "thunk" but it seemed to have stopped, but i drive a crown vic squad car and it too has a "thunk" when u first turn it on. our fleet maintenance says it has to with the a/c ducts sticking. but who knows?

 

The thunk might be related to AC on the Crown Vic but, I'm positive that it's not related to my SCREW. Interesting view point though... wonder what other Ford products are thunking.

RP

 

Rocky Peak,

We must all just be thunking about it too much, don't you think? ...kind of goes with your shat-on statement, wouldn't you say? So, Troy quit calling you Rock Pile, hey?

Later,

~DM~

 

rocket,

i think that "new guy" is prolly mistaking the startup anti-lock thunk with what we are talking about...

daveman,

don't you have a fence to build??? but seriously, have you read any of the other threads about the "thunk"? some guys seem to think the driveline angle isn't what it should be...what do you think...?

troy

 

LMAO!!

Dave, I think we are thinking too much. Heck, here for the past couple of days, I've only had 'CORN and SOYBEANS' to think about. Geesh, you'd think these folks in Minnesota, Iowa, and South Dakota would put up some eye candy while driving down the road. I'd almost rather take a nap...

RP

 

Rock,

I don't know why it is but everyone must think that there's only one Carolina and it must be North. Actually, I live in South Carolina, not North Carolina.

As far as troubleshooting, the other drawback doing it is your own truck is torn down for testing and then your personal mode of transportation is shot. I think that if someone could mount a digital movie camera under a Super Crew and record the activity of the driveline when the "Thunk" takes place, then we'd be on the way to the solution. Only problem is the camera mount would have to be "Rock Pick" solid to see any kind of unusual movement, don't you "thunk"?

Troy,

Couldn't build any fence yesterday because of rain. Besides, the mosquitoes have been bad too as I'm building fence in the woods now and they thrive back there...Got to stay away during certain times of the day you know...West Nile Virus is spreading from state to state...

As for the driveline angle being incorrect, I wouldn't think that would be the problem but that's just my opinion. I will still stand with my original theory that it's not the transmission, not the drive shaft, but is the rear end, the springs, the spring mounts, the spring shackles. In other words, it's in the rear and something is moving and getting stuck, then when you accelerate, it re-positions itself back to it's normal position and then we feel and sometimes hear a "thunk" as a result. I may be wrong but if you want my theroy, then now you've got it.

~DM~

 

Yeah Dave... I think it'd be difficult.

Sorry... South Carolina.... a fence around South Carolina.

RP

 

well guys,

i took the "thunker" back in to the local ford shop this am...will be interesting to see what they try this time. this is the third time and it's getting old...so let's hope they get this sucker fixed or the next time i take it in I might request that they keep it until they are sure it is indeed fixed!

here is some history for those interested or keeping track. the first time i took it in they lubed the slip yoke splines. that worked for about a week...then the thunk came back. second time i took it in they replaced the driveshaft and yoke. that worked for about a week and a half.

at least now they are giving me loaner cars...altho i must say i'm not real found of little cars like the contour they gave me...

wish me luck...