Drive shaft orientation?

[idrivemopar]

I sent out my drive shaft to get checked for balance and true, and they called me today saying that the yoke on one end needed replaced because the u-joints don't seat properly. anyway the end he mentioned was the wide end of the drive shaft and he stated that is the end that goes to the transmission side. My drive shaft has always been installed with the narrow end of the drive shaft at the transmission.

My question, which is correct orientation for the drive shaft, narrow or wide end at the transmission?

Here is what it looks like.

 

[Supershafts]

The narrower side to the REAR, when both sides are swedged the longer section of swedge shaft to the REAR

This is why its good to let experts do things, and not any shop or friends do things because they think they can. That shaft was running out of balance the entire time it was in the car

 

[idrivemopar]

That shaft was running out of balance the entire time it was in the car

Thanks for the feedback!!! Now I believe I know why I always had an unexplained vibration and also why the tail shaft housing on the transmission got destroyed years(well decades) ago. Glad I took this in to get checked out!

 

[69Bee]

Not saying you are wrong, but if a shaft is balanced and checked for runout on each end, why would it matter which end was where?

My Dana used a shaft with a weight, so it could only go one way, but the shaft for the 8 3/4" axle had the narrow section forward, and I didn't have any vibration.

 

[Meep-Meep]

Not saying you are wrong, but if a shaft is balanced and checked for runout on each end, why would it matter which end was where?

My Dana used a shaft with a weight, so it could only go one way, but the shaft for the 8 3/4" axle had the narrow section forward, and I didn't have any vibration.

This is one of those things that I never paid much attention to other than noticing the reduced diameter on one end. My Fords had the rubber isolated shaft and the small diameter end went to the rear. I can look at my MoPar shafts and see how they are but super, being in the business, is probably right.

And I agree if the shaft is balanced and straight why should it matter? Also, I don't get your comment about the dana shaft with the weight that can only go one way.

 

[BeastlyBirdie]

I don't know if it is the actual reason, but I was told years ago the larger end mated with where the power came from. Channeling the force, like a kids toy, a spinning top. Like I said, not sure its the real reason, but, always kept me putting it in with that orientation.
Hopefully super can shed the real reason.

 

[69Bee]

This is one of those things that I never paid much attention to other than noticing the reduced diameter on one end. My Fords had the rubber isolated shaft and the small diameter end went to the rear. I can look at my MoPar shafts and see how they are but super, being in the business, is probably right.

And I agree if the shaft is balanced and straight why should it matter? Also, I don't get your comment about the dana shaft with the weight that can only go one way.

Yea, I agree that Super knows, and I also agree that I never really paid much attention myself. Here is a pic of the inertia ring I am talking about.

 

[Supershafts]

Not saying you are wrong, but if a shaft is balanced and checked for runout on each end, why would it matter which end was where?

My Dana used a shaft with a weight, so it could only go one way, but the shaft for the 8 3/4" axle had the narrow section forward, and I didn't have any vibration.

When a shaft is built it is balanced complete and the slip yoke is part of the shaft, when you remove the slip yoke and even put it back on the same end and index the yoke 180 from it's original index to the shaft it is no longer balanced.
Take the slip and put it at the WRONG end of the shaft and it is no longer balanced.

Just because you didn't feel it doesn't mean it wasn't having an issue, I had a customer come in just yesterday, his carrier had no bearing hubs, the carrier was only being held in place by the axles, all he heard for the past few months was a bearing noise...
Imagine a rear diff that as little as .003 out of adjustment is all you need for everything to perfect or noisy, is now floating around on the axle and has 1.000" back and fourth and all that was heard was a bearing noise....

I don't believe him, but some people never notice it/things, like EVERY limo i get in i always wind up handing them a card and say have your boss call me about that vibration.
No one else in the car heard it or felt it, even the driver, but i did.

The old detroit inertia ring shaft was used in some cars thruout the years, that is not a balanced weight though, the shaft still needs to be balanced.

Changing joints can upset the balance in a shaft, dropping a shaft can upset the balance, people laugh at that but it is a fact, dropping a shaft very likely will upset the balancing and that is the single most reason i do not get involved with shipping anything.

Some cars and trucks can hide vibrations better than others, you not feeling it doesn't mean it's not happening.

.

 

[69Bee]

When a shaft is built it is balanced complete and the slip yoke is part of the shaft, when you remove the slip yoke and even put it back on the same end and index the yoke 180 from it's original index to the shaft it is no longer balanced.
Take the slip and put it at the WRONG end of the shaft and it is no longer balanced.

Just because you didn't feel it doesn't mean it wasn't having an issue, I had a customer come in just yesterday, his carrier had no bearing hubs, the carrier was only being held in place by the axles, all he heard for the past few months was a bearing noise...
Imagine a rear diff that as little as .003 out of adjustment is all you need for everything to perfect or noisy, is now floating around on the axle and has 1.000" back and fourth and all that was heard was a bearing noise....

I don't believe him, but some people never notice it/things, like EVERY limo i get in i always wind up handing them a card and say have your boss call me about that vibration.
No one else in the car heard it or felt it, even the driver, but i did.

The old detroit inertia ring shaft was used in some cars thruout the years, that is not a balanced weight though, the shaft still needs to be balanced.

Changing joints can upset the balance in a shaft, dropping a shaft can upset the balance, people laugh at that but it is a fact, dropping a shaft very likely will upset the balancing and that is the single most reason i do not get involved with shipping anything.

Some cars and trucks can hide vibrations better than others, you not feeling it doesn't mean it's not happening.

.

After re-reading my first five words, my meaning came across wrong. I answered my own question in my mind, and the shaft indeed needs to be balanced with the slip yoke on, otherwise, it is not completely balanced. That would be like balancing the rim, then just throwing the tire on.

The inertia ring acts like a flywheel, it makes the driveshaft require less energy to keep it spinning at the same speed. It is not for balance, although it could plausibly absorb some of the harmonic energy in its mass.

We had a good driveshaft shop here close. Ray retired and moved to Mexico, so we have to go to Tucson now...:icon_sad:

 

[idrivemopar]

I am going to pickup the drive shaft this afternoon, I have some good questions to ask them, thanks Super, just want to confirm if they say the same things as you noted. Not questioning your credibility, but just want to make sure they are good even though I don't have any reason to doubt them. Its more of some additional self education.

 

[idrivemopar]

So, got my drive shaft, and talked to the guy, and as Super stated, right on the money, the wider end is to handle the torque, using the smaller end at the transmission would risk twist off, dropping a drive shaft is also a bad thing!

Anyway, my drive shaft was pretty bad, both yokes replaced, a new slip yoke for the trans, new u-joints, and all rebalanced. I just need to clean it up and clear it and its ready to go!

Thanks for everyone's feedback, its been a good learning experience and I appreciate the knowledge!

Oh, and by the way, I learned something else. The company that used to make the drive shafts for Chrysler was called Detroit Drive shaft or something like that, based in Detroit, which explains why Detroit was stamped on my yoke at one end. The replacements are from the same company, although they are not in business any longer, the parts are still available.

 

[Meep-Meep]

When you said weight it didn't click you were actually talking about the inertia ring. That is used to damp torsional vibrations through the drive train.

 

[Supershafts]

Throw that interta shaft out and get a new AL shaft.

 

[Northwest]

you not feeling it doesn't mean it's not happening.
.

That's what I tell my wife all the time.

 

[rrTor-Red]

that's what i tell my wife all the time.

lmao!

 

[Supershafts]

lmao thats hysterical