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drive shaft balance? #2282926
04/05/17 04:53 PM
04/05/17 04:53 PM
Joined: Dec 2009
Posts: 303
Mesa, AZ
cagebob1 Offline OP
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cagebob1  Offline OP
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Joined: Dec 2009
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Mesa, AZ
For a race only application, Is there a minimum speed at which the driveshaft should be balanced? Would it be crankshaft rpm at the stripe? I know that a lot of shops can't balance at a "high" speed, but what speed is high enough? bow

Re: drive shaft balance? [Re: cagebob1] #2282933
04/05/17 05:10 PM
04/05/17 05:10 PM
Joined: Aug 2005
Posts: 1,652
Amarillo, Tx
old_goat Offline
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Amarillo, Tx
I run a driveline shop in Amarillo. Our machine runs them at about 600 rpm. as long as it is balanced as close as possible,( less than .03 oz) on each end and with less than .005 runout, you should be fine.

Last edited by old_goat; 04/05/17 05:11 PM.

84 D150 440/727
79 /6 swb D150
1964 A100 window van. Just because it has spark plug tubes doesn't mean it's a Hemi.



If ya haven't been there, ya just wouldn't understand.
Re: drive shaft balance? [Re: cagebob1] #2282937
04/05/17 05:13 PM
04/05/17 05:13 PM
Joined: Aug 2005
Posts: 1,652
Amarillo, Tx
old_goat Offline
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We have built lots of drive shafts for sub-9 second cars without complaint.


84 D150 440/727
79 /6 swb D150
1964 A100 window van. Just because it has spark plug tubes doesn't mean it's a Hemi.



If ya haven't been there, ya just wouldn't understand.
Re: drive shaft balance? [Re: cagebob1] #2283661
04/06/17 11:31 PM
04/06/17 11:31 PM
Joined: Jan 2003
Posts: 4,267
Morrow, OH
markz528 Offline
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markz528  Offline
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Morrow, OH
You should always balance a driveshaft at speed. Many will be fine if balanced at 600 rpm but some won't. Most importantly you MUST know what the critical frequency of the shaft is compared to your actual driveshaft speed. 15% difference (critical speed higher than actual driveshaft rpm) is a safe target.

There is a reason I have a 4" mild steel shaft balanced at 7500 rpm in my race car. Smooth as silk.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: drive shaft balance? [Re: cagebob1] #2283667
04/06/17 11:43 PM
04/06/17 11:43 PM
Joined: Jul 2004
Posts: 19,317
State of confusion
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Thumperdart Offline
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State of confusion
Just went through chasing the final vibration in my Dart and it was the shaft and was out of round .008-.010 iirc and was a mess above 5000 r's. Even though my 1350's were still good, he put new ones in and balanced it above 3000r's iirc and it's smoother than ever........... thumbs


72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
Re: drive shaft balance? [Re: Thumperdart] #2283798
04/07/17 09:30 AM
04/07/17 09:30 AM
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Posts: 1,883
Northern OH
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rapom Offline
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Northern OH
What driveshaft companies in Ohio do high speed balancing. I've had mine balanced 3 times by a shop in Cleveland. Each time it is a bit better but still not good enough for my tastes.

Re: drive shaft balance? [Re: Thumperdart] #2283845
04/07/17 11:16 AM
04/07/17 11:16 AM
Joined: Dec 2009
Posts: 303
Mesa, AZ
cagebob1 Offline OP
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cagebob1  Offline OP
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Mesa, AZ
"balanced it above 3000r's "
Is this the critical number? Like most people, I'm on a budget. But I would prefer to do this only once. bow

Re: drive shaft balance? [Re: rapom] #2283876
04/07/17 12:10 PM
04/07/17 12:10 PM
Joined: Feb 2003
Posts: 1,098
Massillon, Ohio
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cudatom Offline
super stock
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Massillon, Ohio
Several people I race with used Custom Clutch in Canton Oh for their driveshafts.

Custom Clutch, Joint & Hydraulics, Inc.
3417 St. Clair Avenue
Cleveland, Ohio 44114
216-431-1630 office 216-431-6048 fax 800-654-0428 toll free
My friends used the Canton location 330-455-1202. No complaints.


Ok
Re: drive shaft balance? [Re: cagebob1] #2283879
04/07/17 12:16 PM
04/07/17 12:16 PM
Joined: Jan 2003
Posts: 4,267
Morrow, OH
markz528 Offline
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Morrow, OH
Originally Posted By cagebob1
"balanced it above 3000r's "
Is this the critical number? Like most people, I'm on a budget. But I would prefer to do this only once. bow


I got mine from Mark Williams.

The critical speed is where it will vibrate and is also known as the resonant point. You don't want to turn your driveshaft above the critical speed (again - stay 15% below it for safety margin).

This really only become a problem for race cars that turn some rpm. But check out Mark Williams site or call them.

http://www.markwilliams.com/driveshafttech.aspx


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......






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