One Piece Drive Shaft Report - For Those On The Fence

[FJfonda]

At 55K miles I have been through 1 drive shaft and 2 sets of the rear u-joints. Early on around 15K the dealer replaced the drive shaft and shimmed to reduce high speed vibration and launch shutter. The result was OK, but not optimal. At 30K a frozen u-joint led me to replace all 3 proactively. At 45K the center u-joint spewed grease from the seal degrading and was replaced. At 55K the rear u-joint froze on our trip home on the 4th of July. Recently, I installed a one piece drive shaft from Dodge... . all I can say is I should have done this earlier. Gone is the launch shutter, all speed ranges are much smoother, and the general "drivability" feels better.

We tow a 12K boat and trailer rig which requires pulling out of the water at steep launch ramps. I can only wonder if that is why we went through so many u-joints. Bottom line is, if you are on the fence --- do it.

Do your homework, talk to the experts, take some measurements, and make the change even if it requires some custom work. You won't regret the money spent and the result.

Thanks to all of the "one piece drive shaft posters" and Rich at Dog House Diesel for the information and advice.

 

[jelag]

I've got a great friend who's been in the drive shaft business for close to 30 years... . he tells me that the manufactures of the equipment and the industry on a whole have a limit for the length of the drive shaft... This limit is the ability of the tube to handle the torque and HP without a lot of flex... .

Take a minute and look at any class 8 truck with 600 hp and 2200 ft lbs of torque... almost any of these trucks could use a one piece drive shaft, that's no longer than the one proposed for our trucks... . and on a truck that size, the larger tube, the size of the U-Joints really isn't an issue... . yet we don't see those trucks with one piece shafts... its because the tubing has too much flex and movement to support the torque and HP..... thus the same is with our trucks...

We recently lengthened the frame on a 3 axle truck we own... . its got a 375 HP Cat with a 15 1/2 clutch... the drive shaft tube must be 4 or 4 1/2 " diameter and the u-joints have to be twice the size of the joints on our trucks... . we ended up with a second carrier bearing and had the make the longest shaft into a 2 piece shaft... we followed simple rules that are proven in the trucking industry using a device to set the angle of the joints and the location of the 2 carrier bearings.....

We have had no problems with this change in over 125K miles... It's my personal experience that the guys in the dealer ship have no idea how to really fix a problem and the factory won't let them really send the truck to a shop that only does drive shafts... that understands the technology and how to set them up..... so they muddle through it with shims, but don't really test and understand the system... .

I personally don't mind having a 2 piece drive shaft... . even SAE (Society of Automotive Engineers) has some standards on this... . correct angles, lengths, size of tube. . etc... I just don't see a change to a one piece shaft as a fix for a problem that a good drive shaft shop can repair... .

Just my thoughts... .

 

[Prairie Dog]

I also went with the 1 piece and it works great. No longer do I have to deal with carrier bearings getting soft on a regular basis. I read all the on-line technical arguments and talked to two drive line builders in my area. The biggest issue with a 1 piece is it has to be bigger to keep from twisting so company's like dodge will have to step up and use better materials. The drive line shops I've spoke with echo the engineering challenges but these have become so popular that they've come to embrace the 1 piece and could give me no anecdotal evidence of any problems with the ones they've seen. For me it was the only way to go.

 

[FJfonda]

Jelag,

Thanks for the insight. Our local drive shaft shop closed and is missed dearly!! When the dealer set up my 2 piece they did use a drive line angle measurement tool although they were learning during the process. I certainly would have been happy to have my 2 piece perform satisfactorily without replacement.

Do you know what the limit is on drive shaft length and is it different aluminum vs steel?

 

[Prairie Dog]

Forgot to mention, if you have a six inch or bigger lift then you dont have to get the DC part shortened.

 

[CDonaldson]

I went with the 1-piece driveshaft after having ALL the same type of issues you have been experiencing. It was the BEST mod I could have done. All that shudder and speed related vibrations are gone.



Dodge went to 1-piece shafts in the 2008's and up. My local dealership told me that driveshaft complaints have been their biggest warranty issues, kind of a forever topic around their shop I guess. They recommended I go to a 1-piece to solve all the problems I was having.





GLAD I changed out all the garbage.







CD

 

[jelag]

I currently own 3 trucks and my boy has 2, all are 3500 quad cabs or larger... . to be honest when we changed the suspension so it wouldn't sag so much with a load, the issues we had when the trucks were new went away... . I'm in the belief that the loaded angles are wrong... on our 04 we found that with a large load the u-joint at the transmission was beating out the seal... . we shortened the shaft 3/4" and added air bags when we have a load... to level the truck... actually all of them have air bags... .

On my trucks alone we have lots of miles... the 04 mentioned above has over 300K... We also feel that by keeping the frame level to the ground we don't have the u-joint failure either... .

These of course are my thoughts and those of the drive shaft shop I talked about... BTW, my friend with the drive shaft shop is in Indiana and I'm in WA, he's never seen my trucks in person... . he's solved my problems for me over the phone... . I share what I find, he listens, has me make some tests and report back... .

In each case it was in the first year of ownership for each truck while they were under warranty... . I just didn't trust my dealers... ...

This has been sort of seat of the pants engineering and changes... but for us its worked for a few reasons... now with a 15K lb trailer the headlights aren't in the trees, and the ride is better loaded... . and OK when its empty... . but these trucks are loaded 85% of the time.....

Hope this helps...

 

[Deleted member 995608]

After doing my own research, the 1-piece driveshaft that Dodge offers is the incorrect length for NV5600 transmission's.



I checked with two local driveline builders in my area and neither one would build a 1-piece unit for truck.

 

[tkerrigan]

I bought the same drive shaft that was too long. Had it shortened 1-1/4" at a drive line shop in Portland for $97. It was worth it.

 

[Prairie Dog]

Spent this weekend towing for the first time since the one piece. Truck performed perfectly - no shutter at launch at all and even when new, it wasn't that smooth.