Driveshaft - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old Dec 19th, 01, 01:33 PM Thread Starter
Tech Team
 
Join Date: Jul 2001
Posts: 58
Question

I've been getting a lot of vibration at high speed (70& above) Did a site search & decided to start with the driveline. I took the driveshaft to the local driveline shop, Inland Empire Driveline & they pointed out that both ends of the shaft don't line up with each other. Approx. 20 degrees offset. Is this normal? Also they say the driveshaft runs out about .050 . What is acceptable tolerance ? I believe the shaft to be original,(#'s car) and they want to replace the pipe, and match both ends. Another guy there says GM offset the ends for harmonics, does this sound right to anyone? Any help would be appreciated, Thanks, Terry
TSN100 is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old Dec 19th, 01, 02:36 PM
Gold Lifetime Member
Robert
 
Join Date: Oct 2000
Location: Simpsonville, SC
Posts: 3,358
Post

Can't help with the run out specs but when I had my driveshaft shortend they showed me up front that it was "15deg out of phase" as they called it. They said this was something Chevy did with the Camaro to help eliminate vibration. They also said that it would be reassembled in phase or in line as I would call it. I've had no problems with the balanced in line version.

------------------
Robert Johnson

'69 getting better every day... (every pay day)
350ci 700r4 3.55 posi

[This message has been edited by rojo (edited 12-19-2001).]
rojo is offline  
post #3 of 6 (permalink) Old Dec 20th, 01, 03:50 AM Thread Starter
Tech Team
 
Join Date: Jul 2001
Posts: 58
Thumbs up

Thanks Robert, I was'nt sure whether to believe these guys, they have been around for awhile and advertise in a lot of hot rod mags, but they did'nt sound to sure of themselves, and seemed way to eager to cut up my driveshaft! May just a misperception on my part. Terry
TSN100 is offline  
 
post #4 of 6 (permalink) Old Dec 20th, 01, 06:42 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,619
Garage
Cool

Gm did it for a reason, and yes, it is to cancel out the vibration at the zero degree of power transfer.

Power traveling through an U-joint is like a sine wave, the positive portion pushes the driving yoke against the driven yoke, the negative portion pulls the driving yoke against the driven yoke. When two joints are lined up on the same plane, the two sine waves are superimposed over each other, in-phase, the term is called.

At the point of every 90 degrees, there is an equilibrium of pushing/pulling, thus, the U-joints are loose, no power is transferring. GM went and offset one joint by 15 degrees to keep the joints under a constant load, thus, no rattles, no shakes.

Remember the example above, we taken one sine wave and moved it about the X-axis by 15 degrees, no equilibrium point now. Driveshaft is always under tension.


------------------
Everett 68/350/PG/11.90/115mph
Everett#2390 is offline  
post #5 of 6 (permalink) Old Dec 20th, 01, 07:01 AM
Senior Tech
 
Join Date: Oct 2001
Location: milw,wi,usa
Posts: 159
Post

Everett#2390 very impressive and interesting
description!I always knew the two joints ran at different angles to cancel each other out but never knew about the 'offset'of the ends.You learn something new every day.
sschevyfan is offline  
post #6 of 6 (permalink) Old Dec 20th, 01, 11:22 AM Thread Starter
Tech Team
 
Join Date: Jul 2001
Posts: 58
Post

thanks guys, your explanation makes sense, you've been a great help. Terry
TSN100 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome