2011 F150, 6.2, 4x4, 29k miles. When accelerating from a stop I get a "clunk" noise in the drive train. I had this same issue/feeling with my F250 and greased the slip joint in the drive shaft. It fixed the issue.
Only problem is, my F150 is a one piece driveshaft. Any ideas?

 

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Goth 150
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Thanks for the link but I have a one piece drive shaft. Just crawled under it to confirm.
However, when I was under it I noticed transmission fluid leaking out of the front. Most likely the front seal. The first 3 days I had the truck the LS clutch packs had to be replaced as well. Starting to think I bought a lemon. So I am probably going to take it back to the dealer and see what they can find, which is another 3 hour one way drive...

 

a 1 piece drive shaft will still have a slip joint.

typically the transmission output shaft acts as the slip joint in this arrangement.

 

Yes but I don't have a center support bearing like that link talks about. Mine has a splined shaft that slides into the rear of the transfer case.

 

10-4

but if the splined connection between the transfer case and driveshaft (aka slip joint) gets dry it will exhibit the same symptoms as the TSB describes.

that is to say: just because ford hasn't issued a TSB for it, does not mean that the condition does not exist.

i'd grease the output shaft and see if that fixes ya up.

 

I was thinking that could be it as well. I'll try and pull it apart tomorrow and see what happens. Is the transfer case a sealed unit or is fluid going to pour out of it when I pull the slip joint out?

 

that, my friend, is a very good question.

I would think it is sealed, but i don't know for sure 100%.

methinks that the outer seal is just to keep dirt out, but not to keep fluid in. there should be an inner seal for the fluid.

maybe someone who as dropped thier driveshaft can confirm?

 

The transfer case fluid lubes the slip joint. If you pull the driveshaft then the fluid will come out. There is no inner seal for the fluid.

 

This is what i think, Most Fords have Backlash in the Rear Differential Case when you come to a stop, not all the time, when you take your foot off of the brake and accelerate you will sometimes get a clunk this is this Backlash that you feel in the drivetrain,I also have a one piece drive shaft

 

Unless the case is OVERFULL you will only lose a small amount of fluid.

 

I'm going to drive it back to the dealer this weekend and let them try and figure it out. The clunk is more than just normal backlash due to the one piece driveshaft. My work truck is the same set up but with the 5.0. It hasn't and doesn't clunk at all.

 

Good idea, kameronth. Let us know when you get a verdict; I'll hang around this thread in case you need my help.

Crystal

 

After 2 1/2 weeks I finally have my new truck back. They had to pull the transmission and replace the front seal. Also, they greased the slip joint and no more clunk. Tonight I will crawl under it to get a better look at the transmission. So far all seems to be operating correctly.

 

Great news, kameronth! I'm glad to hear that your truck is back at home. If I can be of any assistance in the future, just let me know.

Crystal