2 piece drive shaft to 1
 

Ok guy's I want to know if you have noticed any differances in noise from this swap?

Background:
I wear hearing aids in each ear so my hearing is not what it once was! That being said I need to know if what I'm hearing is just the harmonic's of the drive shaft as I was told buy the installer.

The truck drives fine the steering wheel is steady and no shaking at all. At about 75-80 though I can't stand the noise if I have my hearing aids in. Well if I take them out it's fine. That though doesn't answer the question. I want to know if there is a differant sound in your trucks since you swapped out the drive shaft's.
Thanks, not being able to hear sucks!:chevy:

Re: 2 piece drive shaft to 1
 

I have never heard of that one? Driveshaft harmonics would cause a vibration, but I don't see how it could make noise......assuming no bad joints.

I have heard countless numbers of dry joints over the years, but that is not the shaft's fault. It is a maintenence issue.

Re: 2 piece drive shaft to 1
 

This is all new stuff just installed 3-13-14 Thursday on my truck. I'm trying to tell if it's just a new sound with the new 1 peice shaft are is there something wrong with it. The installer say's it fine. I guess I need to get a rider with me and let them hear it and figure out what it is.:chevy:

Re: 2 piece drive shaft to 1
 

I have. one piece in my long bed and I don't hear any noise. havent had over 40 yet. I was having a noise at first but noticed a busted exhaust hanger rubbing against. fixed it no noise. I agree that having another rider night help you figure out if there actually is a problem or if maybe just your hearing aids picking up the sound. good luck

Re: 2 piece drive shaft to 1
 

This is my problem. I don't know if it's me are the truck. I was use to hearing my truck sound a certain way and noww it doesn't so I need to figure this out. ;):chevy:

Re: 2 piece drive shaft to 1
 

exactly. my buddy had surgery on his ears and also wears hearing aids in both. he work with heavy machines and he said that before the surgery an hearing aid upgrade the sounds didn't bother him but now he can't stand them in while he works because he can hear every little noise.

Re: 2 piece drive shaft to 1
 

Maybe.

It wouldn't be noise from the U joints, because the frequency emitted by those (2nd order of shaft rotation) is not in the audible range.

However - sometimes a one piece shaft will transmit rear axle mesh frequencies through the air. It's perceived as axle whine, but you can hear it outside the vehicle rather than inside (the GMT400 trucks with a carbon fiber shaft were particularly bad about this). It will vary based on rear axle ratio but should be in the 370 hz range.

I have never heard of a steel shaft doing this but we've never discussed the hearing aid interaction either. (Maybe it's always been there but we didn't have 'bionic ears' to pick it up - lol)

Probably wouldn't be able to tell further without actual testing. But - the good news is you are not damaging anything so I wouldn't worry about it.

K

Re: 2 piece drive shaft to 1
 

This is something I haven't really thought about. it could be the rear end winning. I have the 4:10 gears so running it at 70-80 MPH could be what I'm hearing.;):chevy:

Re: 2 piece drive shaft to 1
 

Andy one thing to check would be your pinion, driveshaft and engine angles. I had started changing my rear suspension along with lowering it and the engine install and I had a bad pinion angle. I didn't feel bad or anything but I could hear a harmonic. I made sure my engine and transmission was correct to where I wanted it and finished my lowering and suspension upgrades then cut my perches off and fixed it. That noise went away. You might want to check that in case the shop did not.

Re: 2 piece drive shaft to 1
 

I went and looked at your pictures again and you look to be ok as mine was obvious at the rear u-joint. You might still check it tho.

Re: 2 piece drive shaft to 1
 

Yes I need to check it out and see. I hope it's just these dang hearing aids!;):chevy:

Re: 2 piece drive shaft to 1
 

I called Carolina drive shaft who installed the new drive shaft. They said they were in tolerance on the angles. Per there install. ;):chevy:

Re: 2 piece drive shaft to 1
 

Andy, have a few truck/car friends either ride or drive your truck and see if they have any input on the noise. Of course, dont mention the issue before hand. I've had a few long beds with 1 piece drive shafts and never any weird noise. Don't have any idea about the hearing aids tho...are they High Performance models? ;-)

Re: 2 piece drive shaft to 1
 

Driveshafts can ring like a windchime at audible frequencies if they don't have insulation inside them. Many " driveshaft builders" don't stuff their shafts. To check your shaft you can wrap 5-10 layers of duct tape in the center of your shaft to see if the noise changes or goes away completely.

Re: 2 piece drive shaft to 1
 

Good thought, Brad -

K

Re: 2 piece drive shaft to 1
 

I try :)

I figure between me and you we could figure out just about any driveline issue around here.


Any news?

Re: 2 piece drive shaft to 1
 

I went with a one peice drive shaft. I went through 3 carrier bearings in a few years because of the vibrations so one peice eliminated that.

Re: 2 piece drive shaft to 1
 

You two bring a lot of credibility to this site, and your opinions carry a lot of weight with me. All of us are lucky to have you guys around.;)

Re: 2 piece drive shaft to 1
 

AThat's what happens when you don't ballance any driveshaft after changing things, they vibrate. If your one piece shaft wasn't ballanced it would tear up stuff also.

" You two bring a lot of credibility to this site, and your opinions carry a lot of weight with me. All of us are lucky to have you guys around."

Thank you slikslide, its nice to know my efforts are appreciated.

Re: 2 piece drive shaft to 1
 

I'm headed out to the garage and wrap it a few times with tape and see how it does going to the beach. Just in the middle of the shaft right.
Thanks I will report once I drive it again. I have been cleaning it up good for the show so I haven't driven it since last saturday. It's been raining.;):chevy:

Re: 2 piece drive shaft to 1
 

Yeah, the middle would be the single most effective place. Make sure to get the tape thick.

Re: 2 piece drive shaft to 1
 

Well I thught I was going out to the garage. Wife wanted me to help move furniture in the spare bedroom for painting tomorrow. I do it tomorrow night when I get home.;):chevy:

Re: 2 piece drive shaft to 1
 

Andy, are your hearing aids new? Just wondering if you are still getting used to them. My dad went completely deaf 5 years ago and had to get a cochlear implant and he is constantly trying to learn new sounds and tones. He is always asking me to come over and listine to a tractor or chainsaw he worked on. It's weird because some times he can hear thing I can and some times not. I think it has to do with weather or not he is mentally fatigued or not. I know most people don't understand how much work and how mentaly draining it is for someone with implants or aids just to have a conversation yet alone try to work on stuff.
Everyone has givin some great advice on this thread! (That's why I love this forum) I think one of the best things you should try would be well rested and find a rider. Preferably someone who has rode in your truck before. Or even someone from the driveshaft shop.
Can you put your old two piece back in for comparison. (For both you and your rider)?
Also, don't forget the little things. Like checking your fluids! (I say that because I've done that!)
Good luck and looking forward to hear what you find.

Re: 2 piece drive shaft to 1
 

Nope not new. I've had them about 5 years also. It really really sucks not being able to hear!


I don't have the old 2 peice shafts. They kept them which I had no use for them. I can have my buddy who helped me build the truck who is a mechanic by trade but the problem is I'm leaving for the beach either tonight are tomorrow for the car show in Myrtle Beach. I'll try the tape method as mentioned above and see if it changes the sound any.;):chevy:

Re: 2 piece drive shaft to 1
 

Thank you; it's hard to know how much to share and your comments help me (...us...) get that dialed in.

K

Re: 2 piece drive shaft to 1
 

Ok just crawled under it and put several wraps around the center of the shaft. I tapped the housing with my finger and it sounds like a tuning folk. It rings like it's hollow! Is there anyway to put insulation in it other than cutting it open and inserting it. I figure not but thought I would ask.

I guess I need to call them and see what they would charge me to fill it.Can I drill a hole in it and put that wall foam stuff in it?;):chevy:

Re: 2 piece drive shaft to 1
 

Slow down, there, pahdnuh...drive it first. Just because it rings when you hit it with your finger doesn't mean it is a problem.

For any noise issue you have to have three things: an input (aka "the hammer"), a responder ("the bell") and a noise transmission path (either airborne or structure borne). Take away any one of those elements and you no longer have a noise issue.

So - if nothing is hammering on the shaft - then it will not respond and there is no ringing. I'd drive it and see if it's an issue before going too far down the path of filling it with foam.

SIDEBAR:

Just for fun - More science: if it is rear axle mesh frequency that you are hearing (aka "axle whine") then filling the shaft will not help. Axle whine is manifested by exciting the shaft torsionally (ie, it is oscillating like a rubber band, back and forth, while rotating at speed) so you need to kill the shaft by adding a torsional damper.

Using the above "bell" analogy:

Input: "non conjugate" meshing action between the rear axle ring gear and pinion gear

Responder: the drive shaft responds torsionally in accordance with the number of teeth on the pinion gear. Said differently, for a 3.73 rear axle (41 teeth divided by 11 teeth) you can measure a frequency spike coincident with 11th order of propshaft rotation (11 "kicks" per rotation of the shaft). You can kill this response in two ways:
a) Fix the axle mesh
b) Add a torsional damper (like a harmonic balancer) to the shaft. Typically the front u joint is a more suitable location since the shaft amplitude is larger farther away from the input. You may have noticed some of these on C/K trucks as well as M/L vans (because I put them there).

Transmission path: typically is structurally. You can make the noise go away in a Suburban or Van by disconnecting the rear suspension from the body/frame. That may not be a viable option in real life.

K

Re: 2 piece drive shaft to 1
 

...

Re: 2 piece drive shaft to 1
 

Well, Andy, I was going to volunteer to listen to your noise (read take ride in your sweet truck), but it seems you are leaving for to the beach just as I get to Greenville this weekend. My loss. Hope you find your noise.

Re: 2 piece drive shaft to 1
 

^science!

They shouldn't charge you anything to stuff the shaft. If you tap on a shaft it will ring a little even if it is stuffed. Take it for a drive before you jump to too many conclusions.

D*&n you kieth! You know how many times those big a#% dampners smashed my fingers!

Some factory shafts have a short inner steel tube isolated by rubber as a dampner/suffing... those won't smash your fingers KIETH!

Re: 2 piece drive shaft to 1
 

Man you all need to ease up. All I did was ask a question about filling the the thing up. It wasn't like I meant I was going to do it right then. I was just noting what i found.
I just drove the truck 289 miles to Myrtle beach. The tape made it a lot better but it's still there but not near as loud as it was before. At 60-70 it barely noticeable but over 75 and it starts being a pain again.;):chevy:

Re: 2 piece drive shaft to 1
 

Sorry. ;):chevy:

Re: 2 piece drive shaft to 1
 

Did you wrap the tape at the trans end or the diff end? I would go to Home Depot and buy some tar tape ( sound deadening tape ) wrap just one turn and then Some duct tape to hold it in place at the trans end. It would help a lot better.

Re: 2 piece drive shaft to 1
 

If the tape changed it, the shaft needs to at least be checked by the builder. They should fix it for free.

Id call and bait them by asking what they use to stuff their shafts, when the say they don't stuff the shafts you can tell them that you know why your shaft is ringing.

Sorry, we didn't meant to get all worked up. Some people are crazy enough to try "great stuff" in their shaft, ruining the ballance and voiding any type of warranty your driveshaft might have.

Re: 2 piece drive shaft to 1
 

Ok so your saying the shaft needs to be checked for... balancing are having the isulation installed are both.
This drive shaft is under warrinty so no I'm not going to do anything until I talk with them.
Well I headed out to the car show so it will be late this afternoon before I'm back.
A little video of the ride down.;):chevy:

http://www.youtube.com/watch?v=2MZpBt70JVc

Re: 2 piece drive shaft to 1
 

LOL - SCIENCE!!

I think some of the shafts had a cardboard liner as well.

There's a lot going on there, for it just being a piece 'a pipe with some yokes on the end, eh?

;)

K

Re: 2 piece drive shaft to 1
 

The shafts ballance is probably fine (right now). They will have to cut the weld yoke out to check for stuffing, that will affect the ballance so will adding stuffing, so the shaft will need to be reballanced even if that currently isn't an issue.

Re: 2 piece drive shaft to 1
 

Ok thanks I know what I have to do now. When I get back to town I need to call them and setup a time to carry it over. Thanks.
;):chevy: