[FordWilly]

My 2011 4X4 Crew Cab Dually only has 65,000 miles. For some time now I have felt a kind of slop in the drivetrain somewhere. When I start from a stop it is most noticeable. You can just feel it picking up some slack in the line somewhere, with almost a slight clunk.

We just got back from a long trip with our large fifth wheel trailer. On several occasions while hooking up the trailer to leave a location my wife almost panicked. Our routine is that I back up the truck till the Reese/Ford 5ver hitch jaw snaps closed. Then I put the truck in park and get out of the truck to help. All very routine. My wife starts to raise the 5ver electric landing gear to drop the full weight of the trailer onto the hitch. Her panic starts when the weight transfer is at a point where the truck is carrying most of the trailer weight and the landing gear has just a little. At that point the truck (in park) and the trailer together rollback about 8 inches which allows the landing gear foot pads to start to fall off the wood blocks we placed under them. Scares the heck out of my wife. We have 40 years of trailering experience and have never experienced this kind of rollback before now. On this truck the exact same routine has never allowed this large rollback till just recently.

Now the easy 5ver rollback fix is just to engage the parking brake well and/or keep wheels chalked longer. But that does not solve the issue of what in the drive train is allowing this new slop which I feel all the time now when driving. Can the slop be in the tranny? Any thoughts guys?

 

[larrgh]

Never known one to have enough slack in the drive train to roll 8". If you have a camera, smartphone or digital camera, with video, you could start it recording the driveshaft in various places and then try to push the truck to see if you can duplicate this 8" of movement. If you can record various areas, you might see where the problem lies.

 

[Phillippeterson]

It's likely the slip joint where the driveshaft goes in to the transmission. It needs lubing. There's a repair kit from Ford.

 

[chuckster57]

Can't comment on the truck slipping, but IMO you've been lucky you haven't dropped your fiver on the bed.

Been towing fivers since '89 and I have never hitched up and then put it in park. I ALWAYS back under the pin until I hear the handle lock. Then I put my foot on the brake and put the truck in DRIVE, release the brake and Once I feel tension I set the park brake first and then put it in park.

Two things are accomplished, one you've verified that the king pin is in fact locked in and your not putting undue pressure on the parking pawl in the transmission. I also have X chocks between the trailer wheels and they don't come off until the above sequence is done. I have witnessed fivers dropping onto beds.

 

[FordWilly]

Can't comment on the truck slipping, but IMO you've been lucky you haven't dropped your fiver on the bed.

Been towing fivers since '89 and I have never hitched up and then put it in park. I ALWAYS back under the pin until I hear the handle lock. Then I put my foot on the brake and put the truck in DRIVE, release the brake and Once I feel tension I set the park brake first and then put it in park.

Two things are accomplished, one you've verified that the king pin is in fact locked in and your not putting undue pressure on the parking pawl in the transmission. I also have X chocks between the trailer wheels and they don't come off until the above sequence is done. I have witnessed fivers dropping onto beds.

I always hear the hitch handle lock then immediately put the truck in park, get out and insert the hitch lock pin before we lower the landing gear or do anything else. So I know the trailer king pin is securely locked to the hitch. And of course as I stated in my post using the e brake and chocks can solve the two units rolling back together. ----- But the point is why is my truck while in park being able to move between 4 or 8 inches. And where is the drive train feeling of slack when I'm driving coming from.

 

[chuckster57]

A long as your happy with not doing the tug test, I don't really care. I work at an RV dealership and watched a customer back under his big fiver with a brand new truck. He got out and locked the handle, raised the landing gear and when he pulled forward the rest as they say was history.

Trust...VERIFY!!! Have a good day and I hope your drivetrain issue gets fixed to your satisfaction.

 

[FordWilly]

It's likely the slip joint where the driveshaft goes in to the transmission. It needs lubing. There's a repair kit from Ford.

Thanks. When you say the slip joint needs to be lubed, why does that require a kit? What is included in the kit?

 

[STMPDUST]

If your truck rolls 8 inches in park, it should be obvious what's wrong, if not better have it towed to a good shop to examine and fix, cause it aint right! and bad thing are gonna happen, do it before someone is hurt. im sure you will cause you are asking for help here, be careful please!!!

 

[Phillippeterson]

Thanks. When you say the slip joint needs to be lubed, why does that require a kit? What is included in the kit?

I think there's a boot or something to go around a spline ? I'm not sure. I asked what was the clunk on my truck and was told bump yoke slip (or slip bump yoke, or slip yoke bump).

 

[STMPDUST]

Is there really such a kit that will take out 8 inches of roll??, please let us know what turns out to be the issue, i really want to know.

 

[STMPDUST]

FordWilly, what ever happened here? i see you posted on another thread you have no problems with your truck, what did you find out about it rolling 8 inches upon hooking up your trailer?

 

[FordWilly]

FordWilly, what ever happened here? i see you posted on another thread you have no problems with your truck, what did you find out about it rolling 8 inches upon hooking up your trailer?

The trailer is at our winter storage in the desert. Snowing here at our 7000 ft home right now. The truck has just been sitting so I have not thought about it to much, My plan is to take it to Ford for my next major service and have them check out the entire drive line. My wife says the trailer rollback was 6 not 8 inches. But it has never moved back like that before. When the truck is empty it does not move like when the 16000 trailer is pulling on it. The truck is pulling my smaller TT to Alaska in the Spring so I want to make sure everything is 100% for sure. Will post after Ford checks it out.