A Ford tech's take on "THE CLUNK" (THE ONE and ONLY CLUNK THREAD)

[JP7]

BFR - definately get the dealer to lube it up on your first checkup. They should have the TSB and it's better to be proactive than reactive with a moving part like this.

Another great write up SOCO! I too had noticed the many posts from people having this issue - and I'm glad you put all this information in one place. Admittedly, I had described my issue as rear end trouble, as it reminded me of my old trucks which had 200-300k on them and the rear end was a little loose... But the lubing of the slip yoke completely resolved my issue.
As for the whole axle wrap thing - Raptors will experience it - just go in deep snow or mud and you will feel it. But thats the trade off for being able to do high speed bumpy terrain - you just can't have both (without a whole lot of expensive mods).
Again, great explanation and I really hope all Raptor owners can read this, and get the TSB lube job done on their next service to avoid problems.

 

[JP7]

I had the lube job done and it took care of the clunk (yes, opened myself to all kinds of jokes there ) I also noticed wheel hop when doing a burn out or spinning. This has also been diminished after the lube job. I also noticed if I was doing a brake stand, not letting the tires spin, and then letting off the gas so the suspension would settle back down, it would clunk (before the lube, also better now). Just my experiences.

Don't worry RaptorDDS - SOCO's the one that really opened up referencing bad childhood experiences in the same paragraph as 'rear end bind' and 'lube'. You're more than safe - even Bo wouldn't touch that one before going after SOCO...

 

[IRONMAN]

Don't worry RaptorDDS - SOCO's the one that really opened up referencing bad childhood experiences in the same paragraph as 'rear end bind' and 'lube'. You're more than safe - even Bo wouldn't touch that one before going after SOCO...

 

[Raptor62]

Really good explanation of the problem. I have not experienced this problem on mine yet and I don't think I will since I have 11K miles on mine. So Ford can save the lube for someone else.

 

[SilverBolt]

Is there any space on the drive shaft yoke to drill and tap for a Zerk?

 

[iceman302]

BFR - definately get the dealer to lube it up on your first checkup. They should have the TSB and it's better to be proactive than reactive with a moving part like this.

Another great write up SOCO! I too had noticed the many posts from people having this issue - and I'm glad you put all this information in one place. Admittedly, I had described my issue as rear end trouble, as it reminded me of my old trucks which had 200-300k on them and the rear end was a little loose... But the lubing of the slip yoke completely resolved my issue.
As for the whole axle wrap thing - Raptors will experience it - just go in deep snow or mud and you will feel it. But thats the trade off for being able to do high speed bumpy terrain - you just can't have both (without a whole lot of expensive mods).
Again, great explanation and I really hope all Raptor owners can read this, and get the TSB lube job done on their next service to avoid problems.

Its good to know that its common. Mine wheelhopped badly when I had it up in the snow last weekend. The clunk showed up shortly after. I'd bet that the rapid up and down movement of the suspension, combined with the cold and wet, tends to speed up the degradation/displacement of the grease on the slip yoke. My truck will even wheelhop on wet pavement. Its pretty bad. Does anyone else's truck do that?

 

[JP7]

Is there any space on the drive shaft yoke to drill and tap for a Zerk?

I suppose it could be done, but it would have to be at the lower portion in order for the grease to have a hope of getting where it's supposed to be in the splines. From SOCO's explanation though, once greased, the shaft has a seal that should keep the grease in (for the life of the truck?), or at least a long time.
If that seal is compromised, and you get sand/mud in there - you will need to address it sooner than later. I've worn out slip yoke shafts in Bronco's and Suzi's before due to contamination (well, mostly excessive travel).
I'd recommend not putting a grease fitting in the shaft, and just periodically having it lubed if you are into any extreme wheeling.

 

[JP7]

Its good to know that its common. Mine wheelhopped badly when I had it up in the snow last weekend. The clunk showed up shortly after. I'd bet that the rapid up and down movement of the suspension, combined with the cold and wet, tends to speed up the degradation/displacement of the grease on the slip yoke. My truck will even wheelhop on wet pavement. Its pretty bad. Does anyone else's truck do that?

Yeah I get a little hop leaving my driveway which has 6" of ice on it right now. I just back off the throttle a bit and stop trying to go down the damn driveway sideways .
There's about a half inch of sand all over some of the roads here (winter refuse) and when I light up the tires in it, I get some wheel hop then too. I just chalk it up to normal.

The saving grace for axle wrap or wheel hop - is that the Fox shocks increase pressure with distance travelled - so it helps mitigate things a little before flinging parts like leaf spring blocks etc.

I think all Raptors should have the slip yoke lubed, and the tech's can look over the rest of the drivetrain to check for loose parts etc.

 

[Truck Wolf]

1200 miles and I'm having my yoke lubed on Friday. What's puzzling to me is the fact that Ford's SSM stated that trucks built before 1/7/11 might have this issue. What did they do to trucks built after that date to alleviate the problem? I'm guessing they put lots of lube in the slip yoke at the factory.

 

[BDRAG]

My 2004 FX4 had a rear end noise comming from the REAR END at around 5000 miles. It was the whine of the gears. Let it go and it finally got bad enough to need work at around 25,000 miles. Dealer did the repairs, all ne clutches, bearings, seals, the whole nine yards. It was great for about 3 weeks then started the clutch chatter when ya turned and the rear would almost bind up like a locker when turning in a full lock turn.

This went on for a week or so and back to the shop. Trash everywhere in the rear end again. Same deal again, new everything and the set up on the rear end was looser this time in the gears. No whine but the CLUNK was now present. I think most of it is back lash. The truck developed the windup sensation that my 94 Ranger had also developed in its day. Had the Drive shaft lubed as discribed in the tread and its better for 20K or so. It would come back. Lube and its better.


The main irritation was when I was pulling a trailer and had to nail the gas. OH MAN the C L U N K! was horrific and the whole truck would just JERK for a second. The worst would be when this happened and you would get the CLUNK and a loud PING GGGGggggg. From the rear end of driveshaft. Massive noise and violent shift. Ya had to roll into a down shift as easy as posible. I was always waitin for the thing to erup but it never did in 92.000 miles.

My SCREW has the thump feel and the clunk sound at take off. I figgered it was normal as it was in the FX. OhWell. I will get it lubed.

While on noises, ever hear the tires scrubbing even when ya barley roll away from a stop. Windows down and apply the gas and Scrurrrrrrrrbbrbrbrbr go the tires. I hope I can squeeze atleast 20 K from a set. HAhahaaaaaaaaaa.

BDRAG