Home | Register | Login | Contact Us

 
Auto Math
Classifieds
Forum
Gallery
Games
Garage
Tech Articles
Utilites
 
FAQFAQ    SearchSearch    RegisterRegister    Log inLog in    Log in to check your private messagesLog in to check your private messages    Forum Subscriptions1/4 Mile Table 

driveshaft vibration

 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Driveline / Suspension
View previous topic :: View next topic  
Author Message
novadude
Newbie


Joined: 14 Aug 2002
Posts: 15
Location: OK
100.00 points



PostPosted: Sun Jul 20, 2003 12:54 am    Post subject: driveshaft vibration Reply with quote

I just put in a 8.5 rearend in my 77 nova with 4.11 gears, that part is real nice, but the original driveshaft has a small dent in it. I had the driveshaft balanced but the guy told me with the dent he couldn't get it completely balanced. He was right the vibration below 3000 rpm is better but above it starts to shake pretty bad. My question is how can a small dent make that much difference in the balance? Also would a high speed balance be more in order than the lower speed balance? I watch the guy balance the shaft and it was going very fast. One more thing when I switched I went from a 7.5 to a 8.5 the drive shaft seemed to fit just fine, but do you think I needed to shorten it any.

Thanks for the help, David.

_________________
77 nova, 84 GMC 1/2 ton, 92 z28 conv
Back to top
View user's profile Send private message
Hanz
Moderator


Joined: 14 Mar 2003
Posts: 444
Location: Casselberry, FL
4953.56 points


2003 Dodge Ram

PostPosted: Sun Jul 20, 2003 6:02 am    Post subject: Reply with quote

The dent shouldn't make it out of balance, but did the dent cause it to be bent slightly, which would throw it out of balance? I'm really surprised that if he couldn't get it balanced because of that he didn't suggest putting a new tube in it.

Can't tell you about the length difference, just check it, and make sure that it looks like it's into the tailshaft the right amount, probably the same as it was, you can see where it's shiny where it goes in past the seal. Make sure it has more room to go in a little further as the rear end squats or you go over a bump.

_________________
www.hanzenginehouse.com
Back to top
View user's profile Send private message Visit poster's website
jeep_406
Member


Joined: 12 Sep 2002
Posts: 1662
Location: Tewksbury, Mass 01876
53158.50 points


1972 Chevrolet Nova

PostPosted: Sun Jul 20, 2003 12:05 pm    Post subject: Reply with quote

I'm wondering if your pinion angle might be off?
Back to top
View user's profile Send private message Send e-mail
novadude
Newbie


Joined: 14 Aug 2002
Posts: 15
Location: OK
100.00 points



PostPosted: Sun Jul 20, 2003 12:35 pm    Post subject: Reply with quote

I set the pinion angle at 4 degrees down when I put it in the car, but I had to take all back out to have the mounts welded on. I checked an the angle did move a little, I think it may be about 5 down now. I'm running a 350 turbo with a 300hp 350, so maybe I need less pinion angle? I have a set of 2 degree wedges I could try putting them in and see if it might help.
_________________
77 nova, 84 GMC 1/2 ton, 92 z28 conv
Back to top
View user's profile Send private message
novadude
Newbie


Joined: 14 Aug 2002
Posts: 15
Location: OK
100.00 points



PostPosted: Sun Jul 20, 2003 12:35 pm    Post subject: Reply with quote

I set the pinion angle at 4 degrees down when I put it in the car, but I had to take all back out to have the mounts welded on. I checked an the angle did move a little, I think it may be about 5 down now. I'm running a 350 turbo with a 300hp 350, so maybe I need less pinion angle? I have a set of 2 degree wedges I could try putting them in and see if it might help.
_________________
77 nova, 84 GMC 1/2 ton, 92 z28 conv
Back to top
View user's profile Send private message
Guest






100.00 points



PostPosted: Sun Jul 20, 2003 6:58 pm    Post subject: Reply with quote

Hanz wrote:
The dent shouldn't make it out ofbalance, but did the dent cause it to be bent slightly,

it would take a decent blow to dent a drive shaft.
i would opt for a new shaft asap.
alumimun if in the budget.
its no fun dropin a shaft at highway speeds, the outcome WILL be catastrophic.
good luck!
eric
Back to top
osmiumfoot
Member


Joined: 11 Jun 2002
Posts: 299

2387.84 points



PostPosted: Tue Jul 22, 2003 3:36 pm    Post subject: Reply with quote

This sounds like a good argument for a driveshaft loop even if one isn't required for the class you're racing in. Anytime you mess with the drivetrain or up the torque, the breakage ogre rears his ugly head. Until the driveshaft polevault becomes an Olympic event, its probably best to avoid.
Back to top
View user's profile Send private message
novadude
Newbie


Joined: 14 Aug 2002
Posts: 15
Location: OK
100.00 points



PostPosted: Fri Jul 25, 2003 1:40 pm    Post subject: Reply with quote

I went ahead and ordered a new driveshaft from Denny's Driveshafts and I am going to put a loop on when I put the new shaft in. Thanks for all of the advise.
_________________
77 nova, 84 GMC 1/2 ton, 92 z28 conv
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Driveline / Suspension All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
Home | Contact Us | Automath | Cam Files | Dyno Search | Forum | Garage | Picture Gallery | Reaction Timer

Copyright 1997-2018 SMOKEmUP.com All rights reserved.
Advertising Info     Disclaimer     Privacy Policy