Eagle drive shafts

[Tom Y]

I am looking for problems with my Allison world ideas. One that came up is I would need to make my driveshaft longer. I have a 5C with a dropbox. MCI made the driveshaft so the U joints are out of phase. Very odd, but their idea to stop vibration or help with the angles. My question is do the Eagles with dropboxes to the same are or the ujoints matched. Before someone says it was put together wrong, there is only one way it goes together.  Thanks Tom Y

[Brian Diehl]

Tom,
How much out of phase are the u-joints?  Also, what kind of a angle are you currently working with?
Thanks.

[Tom Y]

Brian, Good to here from you. I want to say 45 degrees but wil have to go look. My angles are not bad I did a lot of thinking on this the first time to keep them down. I can not fit the 4000 series (B500) in there. So looking at a 3000 series transmission.  Thanks

[luvrbus]

Tom , Eagle u joints are not out phase the Eagle engine is more offset to the drivers side ( has a very small angle) unlike the 5 that sets on a angle. 


good luck

[Tom Y]

Brian, The U joints are at about 45 degrees. The angles are small, and I haven't had any problems. I spent a lot of time working it out on paper and I had gotten the specs from Spicer for what is permitted.

Clifford, I got the engine in the best I could to keep the angles down. I had take some measurements from the old setup but not enough. I think if I go to a longer drive shaft I will put them in phase.  Thanks

[Brian Diehl]

Tom,
How long of a drive shaft do you need?

[Tom Y]

Brian, I am aways from needing one. I am thinking I need to make up about 11.375". But maybe put the engine ahead? Maybe put a flange on both ends of the shaft? I have one on the dropbox end only now. Once I have a tranny at my place, I can start gathering parts.  Thanks Tom

[rv_safetyman]

Tom, as noted the Eagle shafts are not phased.

It has been a ton of years since I did driveshaft research.

The ideal goal is to have the input and output shafts parallel.  In that configuration, the shaft does not need to be phased (U-joints not at 90 degrees for each end of the shaft.

The problems begin when the shafts are not parallel.  Sounds like that is the case in your bus.  As I recall, there is design process that lets you "calculate" the phase to help offset the velocity "fluctuation" of non-parallel shafts.  As I recall, the phasing only helps to a certain extent.  My tired old memory does not recall much more that 10-15 degrees phasing and nothing like 45 degrees.

Many of you have seen the hugely lifted 4 wheel drive vehicles where they rotate the pinion of the rear end up perhaps 30 degrees.  The rotate the rear end up to keep the standard U-Joint angle to less than about 5 degrees (about max for any reasonable life).  Then the put a constant velocity U-Joint on the transfer case to avoid the velocity fluctuations that would be severe in a standard Cardan joint.

I tried to do a bit of research for this reply and quickly figured out that my memory made the engineering concepts much simpler than they really are.

Wiki has a couple of decent pages:

http://en.wikipedia.org/wiki/Universal_joint

http://en.wikipedia.org/wiki/Constant-velocity_joint

Way more information than you asked for, but what else would you expect from an engineer who is addicted to minutia. 

Jim

[Tom Y]

Jim, The Eagle shafts are in phase, Per Clifford. My shafts are no parallel, as my motor is off slightly. My angles are all well within Spicer specs.  Thanks Tom

[rv_safetyman]

Hi Tom.  Perhaps I didn't use the correct terminology.  When we used to talk about drive shafts in cars, we talked about shafts being phased - that is the yolks were not at 90 degrees and the phasing was expressed in degrees.  If the yolks were at 90 degrees, then we said they were not phased.

In any case, we all agree that the yolks are set at 90 degrees if they are assembled correctly.

Jim