One Piece Driveshaft

[Shawn at Tom Wood's]

I have noticed on my truck the cooler the outside temperature, the milder the shudder. The center bearing support material inside the aluminum frame is very soft. I can pull on it and deflect the driveshaft with very little effort. I don't have another vehicle with a two piece driveshaft to compare it to but I do remember my 1994 Ranger 2wd supercab center bearing was much stiffer material.

I've said this to a few people, that I can physically deflect the rubber bearing mount radially by hand. I'm no wimp but it doesn't require much of my strength and I'm a 170lb person, not a 4,000 truck. If I can easily deflect the rubber, of course the truck will be able to. A stiffer bearing mount would keep the bearing from moving so dramatically from side to side but a stiffer mount might also have less of a dampening effect on the forces causing the bearing to move in the first place. I think this is a bit of a "Chicken or the Egg" question. Is the soft mount causing too much deflection thereby causing the shudder? Or is the shudder inherent to the drive shaft thereby causing the deflection in the bearing? I honestly don't know. Maybe it is both, maybe it creates a feedback loop of sorts.

Regarding the previous conversation about phasing. All these Ranger shafts seem to be out of phase. Here's why: I don't know for sure. I think I know but admittedly I have to presume the intention behind a decision I wasn't a part of and Ford or Dana didn't tell us about. My theory though, which I'm pretty confident is correct, is that the peculiar phasing is there to interrupt one oscillation/shudder/vibration with another. Like they are intentionally adding a vibration to shaft to interrupt the frequency of another, thus reducing the perceived intensity of the issue.

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[NotBudule]

I've said this to a few people, that I can physically deflect the rubber bearing mount radially by hand. I'm no wimp but it doesn't require much of my strength and I'm a 170lb person, not a 4,000 truck. If I can easily deflect the rubber, of course the truck will be able to. A stiffer bearing mount would keep the bearing from moving so dramatically from side to side but a stiffer mount might also have less of a dampening effect on the forces causing the bearing to move in the first place. I think this is a bit of a "Chicken or the Egg" question. Is the soft mount causing too much deflection thereby causing the shudder? Or is the shudder inherent to the drive shaft thereby causing the deflection in the bearing? I honestly don't know. Maybe it is both, maybe it creates a feedback loop of sorts.

Regarding the previous conversation about phasing. All these Ranger shafts seem to be out of phase. Here's why: I don't know for sure. I think I know but admittedly I have to presume the intention behind a decision I wasn't a part of and Ford or Dana didn't tell us about. My theory though, which I'm pretty confident is correct, is that the peculiar phasing is there to interrupt one oscillation/shudder/vibration with another. Like they are intentionally adding a vibration to shaft to interrupt the frequency of another, thus reducing the perceived intensity of the issue.

so in your shop do you have a way to spin/check a two piece like that? Or do you check one at a time ?

 

[Shawn at Tom Wood's]

so in your shop do you have a way to spin/check a two piece like that? Or do you check one at a time ?

We don't. We don't build any two piece rear shafts. That is primarily because we are a specialized shop, building shafts for Jeeps and small trucks, no full size truck shafts. Theoretically though, a two piece would need to be balanced as a complete assembly but I believe that the problem with these trucks has something to do with the working geometry of the shafts. Any time a shaft is in a balancing machine it is being balanced in a perfectly straight line. The intention of dynamically balancing the shaft is to ensure that there is not a high side or a low side in terms of rotating mass. By balancing a shaft in a controlled setting, at no angle, with only a 3hp motor driving it, and no resistance, it's easy enough to get something that runs smoothly. Take that same shaft and put it into a vehicle with angles, constantly changing angles due to suspension movement, variable amounts of torque and resistance, and all the other things that happen in real life operation of a drive shaft, and the result can be a drive shaft that all of the sudden has issues.

 

[TJC]

I know nothing about driveshafts but, how can one tell if its out of phase? Is there something I can check for (visually) under the truck?

See the image below.. My driveshaft is about 25-30 degrees out based upon a quick eyeball glance. I did not measure it.

 

[TJC]

They are all out of phase.
Ford designed it that way for some reason.
Its not the smoking gun for the vibration some seem to think it is.

FWIW, I was making an observation, nothing more.

 

[Justin says...]

See the image below.. My driveshaft is about 25-30 degrees out based upon a quick eyeball glance. I did not measure it.

I didnt notice the difference earlier, whoops! It was early? Yeah we'll go with that.
Thanks!

 

[TJC]

Good to hear! I just have the low speed shudder (4-8mph) but in a lot of stop and go traffic it's annoying! How difficult was it to change? How much time?

Not too bad, I am 67 and it took me a couple of hours. I have a 2 post lift in my garage so that helped. I'm too old to be crawling around on the ground! I raised the truck about 4' after I pulled the emergency brake. I did have to rotate the shaft to gain access to all the bolts. That meant releasing the e-brake and putting the car in neutral so the shaft could be rotated, then resetting the e-brake, and going back to park. Once the shaft is installed you should release the e-brake and go to neutral, then check the shaft for binding by rotating it. Very easy to do. If it is binding you'll need to figure out why. But that is generally not a problem.

4 bolts on each end and 2 on the carrier. Only 8 bolts with the solid driveshaft, 4 on each end. I did it alone and taking the old one off was a bit of challenge. I didn't want to drop it. Loosened everything first, then took the end bolts out, then the carrier bolts. The axle end easily pulled free. Had to use a rubber mallet on the transfer case to pop the shaft loose. Removed the carrier and lowered the shaft to the ground. The solid shaft was a bit heavier than the 2 piece, but installed easier.

I installed with the slip joint on the transfer case end, less road grim to pick up. AT least that is my theory. It can be installed in either direction. Don't forget to use Loctite Blue on the bolt threads.

 

[navsnipe]

Not too bad, I am 67 and it took me a couple of hours. I have a 2 post lift in my garage so that helped. I'm too old to be crawling around on the ground! I raised the truck about 4' after I pulled the emergency brake. I did have to rotate the shaft to gain access to all the bolts. That meant releasing the e-brake and putting the car in neutral so the shaft could be rotated, then resetting the e-brake, and going back to park. Once the shaft is installed you should release the e-brake and go to neutral, then check the shaft for binding by rotating it. Very easy to do. If it is binding you'll need to figure out why. But that is generally not a problem.

4 bolts on each end and 2 on the carrier. Only 8 bolts with the solid driveshaft, 4 on each end. I did it alone and taking the old one off was a bit of challenge. I didn't want to drop it. Loosened everything first, then took the end bolts out, then the carrier bolts. The axle end easily pulled free. Had to use a rubber mallet on the transfer case to pop the shaft loose. Removed the carrier and lowered the shaft to the ground. The solid shaft was a bit heavier than the 2 piece, but installed easier.

I installed with the slip joint on the transfer case end, less road grim to pick up. AT least that is my theory. It can be installed in either direction. Don't forget to use Loctite Blue on the bolt threads.

Hopefully you installed the spacer that came with the new shaft on the transfer case flange before you installed the shaft.

 

[TJC]

Hopefully you installed the spacer that came with the new shaft on the transfer case flange before you installed the shaft.

Yep.

 

[navsnipe]

I did a google search for "driveshaft intentionally out of phase" and found this technique is somewhat common.

 

[TJC]

I did a google search for "driveshaft intentionally out of phase" and found this technique is somewhat common.

Interesting, as I have been researching as well.

 

[navsnipe]

I just read a couple of threads where people injected silicone caulk into the center bearing rubber support gaps on Toyota Tacoma's to help with the shudder.

I guess we do have something in common with these guys.
https://www.tacomaworld.com/threads/carrier-bearing-silicone-packed.355987/

 

[TJC]

I have noticed on my truck the cooler the outside temperature, the milder the shudder.

I don't have it when the truck is first started, when the truck is cold, but after 10 minutes driving, the low speed shudder presents itself. No idea about high speeds as I won't go that fast until engine and turbo reaches operating temperatures.

 

[TJC]

It has been 3 weeks since the driveshaft swap. All of the shakes and shudders are gone. My wife even noticed and commented on the difference!

My truck had them upon startup until about 20mph and when coming to a stop (I'd get speed jerks when the transmission down shifted), as well as at high 70mph+ cruise speeds.

Ford should have delivered this level of quality in the first place. The truck should not be sold with this much slop in the drive train.

I also have a difficult time believing that the vibrations in the driveshaft don't have a negative effect on the life of the bearings / seals in the transmission and rear axle.

Ford could and should have designed a better solution.

Anyway, count me as a happy camper. The shakes and shudders are finally a thing of the past. My 2020 Ranger now drives as smooth as my 2005 Ranger.

 

[navsnipe]

I installed my Tom Woods driveshaft today. One word, Wonderful!!!
For two years of dealing with the shudders, clunks, and vibrations and they're now gone.
I agree with all that has been said from others who have changed to a one-piece driveshaft.
It was well worth it!

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