mikek,

mine does exactly what you described. i can put it in neutral and no thunk. obviously there is binding somewhere in the driveline, which i believe is centered somewhere around the yoke/driveshaft and output shaft of the tranny. doubt it's the rear axle since that would still be turning even when the truck is in neutral and rolling...

 

I treid the neutral bit once and it did stop smooth but mine stops smooth some times in Drive also. I'll keep on trying to see if I can spot a pattern.

 

Kyfordfreak. Mine is exactly the same. I can't make the 'thunk' happen each and everytime on a slow down or a take off from a light. It's intermittent in some regards. I haven't been able to make much of a correlation either.

Mine doesn't thunk in neutral either.

Interesting problem we have here.

RP

 

had this thunk shudder problem in an '88 f150 4x4 I used to have did lube every thing replace universal joints and all turned out the bushings in the trans mount had worn all to heck and one had broke and fell out because the mount bolt had loosened

dont know if this will help but sounds close to your problem had "clunk" at stop and take off "shudder" at shifting

also had bad shudder in my '00 f150 turned out drive shaft had been dented when shipped here from mainland (dent was about 1" deep love that aluminium) you said had drive shaft replaced so cant be it besides had no clunk

hope this helps

Roy in hawaii

'00 F150 xcab
5.4 L
nothing special
owned 5 ford truck no cars and one jeep (forgive me)
also sold them for year and a half

 

Rockpick
There seems to be no rhyme or reason to the "Infamous Ford Clunk" it seems to come in a wide variety.
I have come to accept the clunk somewhat, but would still like to figure it out. I still can't decide if it's driveline slop, broken mounts (don't think so, too many new ones doing it also), rear axle movement (kind of like axle wrap) or if it's brake related (drums on mine).
I paln to replace the u-joints soon and will regrease the slip yoke. Then I plan to check out those rear drums and shoes. From there I might try Mitch's fix with a set of helper springs.

 

my thunk is obviously somehow related to the area around the slip yoke/driveshaft/output shaft because the two times i've had the truck in, and they've lubed the yoke splines...the problem has disappeared for about a week or so. i'm just wondering if ford has an issue between the splines on the yoke and those on the output shaft...?

 

Troy, Ford doesn't have any real issues with the slip yoke, but I think that I would ask your dealer to replace the slipyoke since lubing it seems to help, maybe yours has a little abnormal wear or wasn't machined properly. I've fixed a few clunks by lubing slip yoke but its usually a temporary fix.

 

I just purchase my used Supercrew 4x4 a month ago with only 19k miles on it. A week later I notice a thunk coming from the drivline while braking and then accelerating at slow speeds. I took it to Ford and they replaced my slip yoke, but a week later the problem returned. Now it seems to be worse than before. It feels like it is coming from the transfer case. Is the same problem that everyone else is having? I am relucktant to return it to Ford since it seems they don't know how to fix it. Any suggestions????

 

actually, the last time i took the truck in, they took a yoke and driveshaft off a new s-crew sitting on the lot and put it on mine...unfortunately the thunk returned about a week later.

 

Be careful about what U-joints you use on these trucks. The aluminum shafts take a special coated cap, using the reg. ones apparently results in corrosion and failure of the yokes. Not an expert, it was on another thread,,,,98

 

I just found this, on an S-crew too!!! Check out Area 52s' thread in Suspension also. It's called "Anyone checked their driveline angle?" or something to that effect. This may be the culprit of the thunk??,,,,98

https://www.f150online.com/galleries...7170&anum=2302

The thread!

https://www.f150online.com/forums/sh...threadid=86469

 

I too, believe the clunk/thunk that we experience when coming to a stop is caused by the driveline in some way. I didn't have this problem until after my slip yoke was lubed in an attempt to fix the other clank that occurs at low speed after coasting and then accelerating again or sometimes when slowing down as the truck downshifts.

I took the truck back to the last servicing dealer and let the service manager drive it this week. He did experience both problems and said he wishes there was something he could do for it but that it is normal on these trucks due to their long wheelbase and the fact that the drive shaft angle changes when braking, etc. causing it to slip in and out in the yoke.

I'm curious to know if anyone with the two piece driveshaft has these same problems.

HiO

Here's some other info

https://www.f150online.com/forums/sh...threadid=86750

 

Who at Ford thought it was ever a good idea to bolt the exhaust to the Trans mount. It's the first time in my 34 years that I've EVER seen that done on any vehicle???,,,,98

 

an engineering rep is coming out to look at my truck. local dealership is getting frustrated trying to fix my "thunker" and thus have decided to step it up to someone higher before they just start replacing all kinds of parts...

 

TroyK,

I will be very interested in what the FORD expert says. I have been on another Forum and it has ended so far with ford having to send an Expert to check out the problem. The last time I was at the ford dealership, their service forman told me there was nothing he could do and that it was normal. I love my truck, but I am getting frustrated with fords responce.

I also had my driveline and slip-yoke replaced with no fix...