Driveshaft Phasing

[CO2Ranger]

Waiting for the '21s to make it to the lot so I can see for myself if this is still an issue. Might be able to buy myself one again if the issue is resolved.

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[ryyck]

HI Matt,

Driveshaft length is determines the critical speed of the shaft. This speed is when the driveshaft starts to "jump rope". When the Driveshaft is too long, critical speed of the shaft can be lowered into the actual vehicle speed range.. Not allowed by Ford. So for longer driveshafts, you can increase the diameter of the shaft, change the material to aluminum or composite, or resort to a two piece shaft which is inherently prone to start up shudder. Why the Ranger program chose the two piece is beyond me, but they did for some reason. This has nothing do do with phasing which is that the U joint Yokes are all aligned. The video with a yard stick is an attempt to show misphased U joints, but failed in my opinion as I could not determine if the two shafts were actually out of phase. Giving benefit of the doubt to the video. It would be that the shafts were one output spline off. The fix is to reindex the the rear driveshaft one spline.

Most times on two piece driveshafts, the misindex is addressed by making the spline shaft with a blocked spline which means the drive shaft and the slip yoke can only go on in one way...but I do not know if the Aussies that designed the Ranger did this.

So my recommendation is to take it back to the dealer for addressing the out of phase driveline.

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

Gotta love ya. Have no idea of your Klingon speak...but respect your knowledge and experience.

 

[CO2Ranger]

So update on this. I test drove a 2021 XLT and noticed vibration at takeoff and a slight shudder around 50mph. This truck had 18 miles on it so I expected some harshness due to the tranny learning, but this vibration felt different as it was clearly between shifts, not during.

I pick up my Lariat today and have fingers crossed that the vibration is non-existent, though if I had to choose, I'd rather have it at 50mph than the 70+ that my 2019 had.

 

[navsnipe]

So update on this. I test drove a 2021 XLT and noticed vibration at takeoff and a slight shudder around 50mph. This truck had 18 miles on it so I expected some harshness due to the tranny learning, but this vibration felt different as it was clearly between shifts, not during.

I pick up my Lariat today and have fingers crossed that the vibration is non-existent, though if I had to choose, I'd rather have it at 50mph than the 70+ that my 2019 had.

Really sucks to hear this turd is still not polished.

 

[CO2Ranger]

Really sucks to hear this turd is still not polished.

I was a little surprised myself. Thought for sure they would have made some adjustments. I know one member had the shaft rebalanced and hasn't had issues since, but if I can avoid that hassle on a new truck I'll gladly do that.

 

[CO2Ranger]

Pleased to report that my new Lariat has a butter-smooth acceleration up to at least 80mph. It has a slight shudder at takeoff, but perfect at all other speeds. Got lucky and am very pleased with my new Ranger.

 

[navsnipe]

Pleased to report that my new Lariat has a butter-smooth acceleration up to at least 80mph. It has a slight shudder at takeoff, but perfect at all other speeds. Got lucky and am very pleased with my new Ranger.

Did you get a 2021 Ranger? I see your profile shows a 2019 Ranger Lariat FX4.

 

[CO2Ranger]

Did you get a 2021 Ranger? I see your profile shows a 2019 Ranger Lariat FX4.

New one is 2021, yes. Updated my picture but not my profile yet.

 

[navsnipe]

New one is 2021, yes. Updated my picture but not my profile yet.

Why did you get rid of your 2019?

 

[CO2Ranger]

Why did you get rid of your 2019?

COVID layoff. Back in the saddle again finally.

 

[Milkmaster]

Found this forum by doing a search on high speed vibrations on the new Ranger. I read through this entire thread. Made a few notes and tried a few things including my local tire shop and local Ford dealer. My 2020 Ranger has the dreaded driveline vibration. 7K miles and now on third set of tires. IT AINT TIRES! I tried the 1/8" shims beneath the driveshaft center bearing mount. I guess it might have helped a little, but not much difference. The overall best results have been noted by reducing my tire pressure to ~32psi. At least now I don't also feel every little imperfection in the pavement like before. At least it is a lot smoother bouncing around town. At highway speeds I am Not happy with it, but I doubt it will get any better than it is now. Otherwise the truck runs fine.

 

[Ogden Dan]

Found this forum by doing a search on high speed vibrations on the new Ranger. I read through this entire thread. Made a few notes and tried a few things including my local tire shop and local Ford dealer. My 2020 Ranger has the dreaded driveline vibration. 7K miles and now on third set of tires. IT AINT TIRES! I tried the 1/8" shims beneath the driveshaft center bearing mount. I guess it might have helped a little, but not much difference. The overall best results have been noted by reducing my tire pressure to ~32psi. At least now I don't also feel every little imperfection in the pavement like before. At least it is a lot smoother bouncing around town. At highway speeds I am Not happy with it, but I doubt it will get any better than it is now. Otherwise the truck runs fine.

Best thing to do is perform a frequency analysis at the speed you are feeling the vibration the most. This way you can determine the source of the vibration (normally wheel and/or driveshaft). There are many phone apps that work quite well for this that utilize the accelerometers in your phone.

Dan

 

[Milkmaster]

Best thing to do is perform a frequency analysis at the speed you are feeling the vibration the most. This way you can determine the source of the vibration (normally wheel and/or driveshaft). There are many phone apps that work quite well for this that utilize the accelerometers in your phone.

Dan

I could do the accelerometer thing for sure. Is there any chart or other information to help diagnose the cause based on the vibration frequency results?

 

[Blue Streak]

Am I wrong to assume that if you have a vibration at 55mph & Ford installs different shims to cure the vibration at 55mph, does this not cause the vibration to occur at a different speed. Trying to see why the change does not cause another problem. ?

 

[DukeCanBuildit]

Yeah, I shudder a bit between 75-80 but it disappears after 80....so, you know the rest. ?

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