I'm still getting used to this new to me FX4, with 48k miles. So this may be normal. Upon taking off from a stand still I feel a light clunk like something is engaging. Don't get too fixated on the poor terminology of "clunk", couldn't think of a better word. Almost like a 1"1/2" ball in a 2" trailer hitch is engaging from a stop. Could be a loose/worn drive shaft, u joint, too much backlash? Or nothing at all and it's just a normal occurance for F150s?

Note: my Ford dealer did give the truck an inspection and didn't see any problems? Doesn't mean they didn't miss anything either...

 

It sounds like the slip yoke needs a little bit of grease. It's a fairly common thing and is more of an annoyance than a real problem if this is the issue.

 

Mine's been doing it too. I did some googling to see what the best way to fix it might be, but I found mixed results. Do you know if I can just use regular all-purpose grease?

 

The dealer lubed the slip yolk on my 2011 at about 32,000 and at 62,000, it's back.

Sent from my iPhone using IB AutoGroup

 

There's a teflon grease that you are supposed to use.

 

For me it's more of a annoyance than a real problem. My truck does it a little bit and one day I'll crawl under it and fix it. But since it's not a real pressing issue it can wait till the weather is nice and I have some free time. The grease Ford uses works well but seems to wear off or dry out. I was thinking about putting some high temp axle grease on it then a layer of CV joint grease. The CV grease has water repellent in it that might keep the yoke lubed longer.

 

I had the same and bought a tube of the ford teflon grease. The joint is inside a seal so doesn't actually see any water. I suspect it will be something that needs doing every year or two. Takes 20 minutes with the right tools handy. You'll need a pair of sidecutters (to remove the clamp holding the end of the bellow seal in place), a 12 sided 13mm socket to remove the driveshaft from the differential, the grease and a zip tie to replace the clamp with.


TSB
10-22-6
• REAR DRIVESHAFT SLIP/BUMP - BUILT ON OR BEFORE 12/1/2009
Publication Date: November 3, 2010


FORD:
2009-2010 F-150
This article supersedes TSB 09-25-5 to update the Service Procedure.
ISSUE:

Some 2009-2010 F-150 vehicles equipped with a 2-piece driveshaft only and built on or before 12/1/2009 may exhibit a rear driveshaft slip/bump concern on light to moderate acceleration from a stop or when coming to a stop with light braking.
ACTION:

Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE

It is not necessary to remove the entire driveshaft from the vehicle for this repair.
1. Mark the rear driveshaft flange and differential pinion flange.
2. Mark the center slip yoke barrel across the boot and the clamp crimp heads to the rear shaft spline stud shoulder. (Figure 1)


Figure 1 - Article 10-22-6
3. Remove the clamps from the center slip yoke and discard.
4. Remove the rear axle to driveshaft flange fasteners and remove the rear portion of the driveshaft only.
5. Remove the boot.
6. With a clean towel thoroughly clean old grease from the splines on the slip yoke only. Do not use solvent.
7. On 4X4 vehicles only, using hand tools, loosen the center bearing bolts and slide the center bearing fully rearward in the slotted holes.
8. Torque fasteners to 35 lb-ft (48 N-m). Refer to WSM, Section 205-01 for detail.
9. Apply an even coat of Motorcraft® PTFE Lubricant to the internal splines of the yoke only. Amount of lubricant applied to the yoke should be 1/2 of the tube contents. (Figure 2)


Figure 2 - Article 10-22-6
10. Position boot and clamps over the spline portion of the driveshaft. Do not crimp the clamp at this time.
11. Install the rear portion of the driveshaft into the center slip yoke.
12. Fasten driveshaft flange to the rear axle using the previous alignment marks for reference. Refer to WSM, Section 205-01 for detail.
13. Position the clamp heads in-line with the alignment mark on the slip yoke and stud spline shoulder to minimize any balance shift.
14. Crimp clamps using service tool ESST 205-343.
Other driveline noise conditions will not be corrected with this procedure. Refer to appropriate WSM for diagnosis and repair for engagement clunk, hesitation during light throttle 1-2 upshift, harsh downshift while coasting 15 MPH (24 Km/h) and, shudder/vibration on moderate to hard acceleration. See other applicable Technical Service Bulletins for details.



PART NUMBER
PART NAME
XG-8
Motorcraft® PTFE Lubricant
9L3Z-4421-A
Spline Boot
9L3Z-3B478-A
Clamp (2 Req.)
WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATION
DESCRIPTION
TIME
102206A
2009-2010 F-150: Clean And Lubricate The Splines Of The Driveshaft Slip Yoke Following The Service Procedure (Do Not Use With Any Other Labor Operations)
0.5 Hr.
DEALER CODING

BASIC PART NO.
CONDITION CODE
4602
41

 

Thank you tcp2. That's exactly the help I was looking for.

 

Yesterday I took mine to a local shop that specializes in Fords and described the issue. He said he knew exactly what I was talking about. He already had the Teflon grease in his shop. Half an hour and 40 bucks later, the truck is riding smooth. Good as new

 

Just did this on my 2011 with the official Ford grease. I didn't remember how smooth it used to be. The clunk gets worse and worse over time but it's so slow as to not notice it. Now, it also unmasked a shudder when taking off in first gear. That's always been there but the clunk covered it up. Time to search for the cause of the shudder.

 

There is a kit from motorcraft with white ptfe grease and includes boot and clamp.

 

Yes, I saw that after I did the fix. I saw the TSB and went with the part number on that, which was only the grease. Next time I know. And, based on the forums, there will be a next time....

 

Like others have said, it is a recurring maintenance item. I do mine once a year and then realize how the clunk has crept up over the year. You honestly don't need to replace the boot. Remove one clamp and just replace it with a zip tie. The driveshaft has a groove and the boot has a bump that makes it stay in place. A small tube of grease looks like it will go 4 applications for me. Edit to my above post, it's a 12mm 12 point socket that removes the 4 bolts at the end of the driveshaft.