Greasing the Slip Yoke Cured Several of Issues for me

[FaaWrenchBndr]

So my vibration is worse after I did this . 75+ MPH is no bueno.

I wonder if the slight looseness in the slip yoke from lack of grease was soaking up some of the drive line chatter and now that it's "tighter" with the grease, I'm feeling it more. Driveshaft went back exactly as it was marked, too.

I wondering if they put the driveshaft on wrong from the factory based on how they balanced it.

Also, my transmission is making a very loud whining noise, almost like a supercharger on a Hellcat. It shifts fine, but getting louder. Could that be it, as well? Who know...but it's annoying me.

your issues may be the transmission and not the driveshaft at all.

Sponsored

 

[Dakar09]

your issues may be the transmission and not the driveshaft at all.

I am leaning this way. My 2012 Volvo XC70 had this sort of vibration almost the entire time I had it, and they replaced everything including the axle shafts and torque converter, and only after they put a new transmission in did it go away. And that car never had issues with performance or weird shifting patterns to indicate there was an issue in there. Just the vibration.

And a dealer won't believe me, lol

 

[Joe_Lee]

Thanks to the OP and everyone who chimed in. I ordered the bolts and grease and did mine yesterday and cured the clunk!

 

[spiritrider1]

I'm so glad I ran into this thread! I began noticing a small clunk a couple months ago which at about 65k miles on my PB 4x4. I did a full drivetrain lube & fluid change back in May in preparation for a 3k round trip to visit the grandkids. ICE oil, front & back diff, x-fer case, all with Amsoil. At the time Amsoil didn't have ULV but their spec sheet indicated their LV Signature fuel saving fluid was rated for the 10R80H. I then had the notorious 'bump' as if being hit from behind. The electric motor that pumps tranny fluid when the ICE is off began to fail. I Luckily got it changed on extended warranty just before my trip. But Ford dumped my fresh Amsoil (luckily it was a drop & fill) and put the Ford ULV back in. I was worried I may have done something by using the Amsoil when I began hearing the clunking while braking. I don't think I ever heard anything during accelleration though.

Bought a bag of bolts and the PTFE lube at the dealer for $18 (my son is a porter there and got me a discount) and got busy. Clunk is GONE! I really don't see how or what could make a clunk since I don't see anything that impacts when the splines slide in the shaft. At least the end of the shaft didn't exhibit any markings as if it makes contact with anything.

Either way, job done and half a tube of lube left. Now, what else can I smear this stuff on?

 

[Zappy]

This clunk people are mentioning, does it occur on downshift or upshift around 20-25mph, should be when it goes into 4th?

I do want to check the drive shaft now in general as I'm the 2nd owner and who the hell knows lol.

 

[spiritrider1]

This clunk people are mentioning, does it occur on downshift or upshift around 20-25mph, should be when it goes into 4th?

I do want to check the drive shaft now in general as I'm the 2nd owner and who the hell knows lol.

It's when decelerating and applying brakes. I found it would happen at lower speeds/gears approaching a stop, 4th to 3rd or 2nd and probably less than 25mph. I don't think I ever heard anything when accelerating. But I have a PowerBoost so I'm accustomed to feeling the little bump when the ICE kicks in right as the roll starts in 1st. It's a PB thing...

 

[Jerome10]

I did mine I don't know, maybe a month ago finally.

I think it has helped the clunk around 60mph that I'd get with the off-the-gas-a-few-seconds then back-on-the-gas. It isn't gone but I am pretty confident it is 85% less severe.

It hasn't helped my truck feel like it shifts any more smoothly.

Easy enough and cheap enough to just go ahead and do it but I don't think I'd expect any miracles for clunking/thunking/gearchanges/lurches etc

 

[Jerome10]

This clunk people are mentioning, does it occur on downshift or upshift around 20-25mph, should be when it goes into 4th?

I do want to check the drive shaft now in general as I'm the 2nd owner and who the hell knows lol.

For me, no. Its an off-throttle, then back on throttle clunk. 60mph and slight downhill being the worst for me.

With that said, I think I know what you're discussing on the downshift/upshift and 4th gear. Though mine is around 24mph downshift from 6th to 5th. I frequently get a lurch, like driving a manual and downshifting and dumping the clutch too quickly. Drives me bonkers. Lubing spline didn't do anything for me and this problem.

 

[astro_fusion]

The clunk is on low speed acceleration usually from a stop after moderate braking. It feels like your rear wheels are delayed 1/4 turn before you get moving much, then the clunk/thud and you're off and going normal. It's the slip yoke binding while the truck is squatting under the weight transfer from taking off. The bound driveline restricts the leafs from cycling correctly. This causes the driveline ends to be at an incorrect angles and the u joints get out of phase causing the thud. It's not much movement but if something binds in any leaf spring set up you usually experience this. The thud is the driveshaft recoiling back into the transmission after coming back into phase and unbinding.

Simply a momentary driveline angle error

The high speed clunks and thuds I believe are just back lash at/in the axle or the transmission.

The aluminum driveshaft and mono/composite leafs amplify it

Cure the clunk, pull it out, lube it up

 

[Zappy]

How long of a job is it, an hour?

 

[Gros Ventre]

The slip joint is there for minor changes in length of the driveline. When it sticks it prevents these changes in length and the rear springs absorb the change until they snap it back to a "comfortable" length. The clunk you hear occurs when the springs push the axle back to where it belongs. Note: this isn't much movement, but enough to give the clunk.

 

[bjl95mustang]

My 24 was greased when I checked. I had a container of the ford ptfe grease and added some anyway.

Only bad thing is I could not get the truck to stay in neutral. They removed the pull string behind the panel. And I couldn’t figure out hot to keep it from auto shifting back into park. I was able to get it lined back up after the second attempt of stabbing the drive shaft. Last resort plan was going to jack up the rear.

 

[Hans Moleman]

My 24 was greased when I checked. I had a container of the ford ptfe grease and added some anyway.

Only bad thing is I could not get the truck to stay in neutral. They removed the pull string behind the panel. And I couldn’t figure out hot to keep it from auto shifting back into park. I was able to get it lined back up after the second attempt of stabbing the drive shaft. Last resort plan was going to jack up the rear.

Here is what I did to keep it in neutral so I could rotate the driveshaft by hand. Mine has the emergency release cord behind the panel but I didn’t want to mess with it.

1. Turn truck on .
2. Shift into neutral
3. Press ‘M’ button.
4. Turn truck off.

You have 30 minutes to stay in neutral to do your business until it goes back to park automatically.

 

[bjl95mustang]

I tried that. Or thought I was doing it right. I tied about every combination of buttons.

No luck for me.

 

[JohnTrigger]

The exact sequence is here, maybe had to do with when you released foot pressure on brake during the sequence.

https://www.fordservicecontent.com/...A&div=f&vFilteringEnabled=False&buildtype=web

Sponsored