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novadose454
11-25-2009, 11:20 PM
ok...lets see how you guys can figure this one out...
at sixty miles an hour....im running smooth in overdrive.....steady sixty.....now lets say the road just levels out and the car freewheels....meaning the motor is going as fast as the car ...not acceleratiiing....and not having the motor slow the car....at that point...i get this vibration thru the drive train......rebuilt the rear...new bearings....double checked lash etc.......all good.....sent the axle to supershaft he balanced it....all good...bearings on the axles...all new....smooth.....called art carr he said that its not from the tranny.....could it possibly be the angle of the pinion...?? next thing to check...anything else..???? you tell me..
mikelbeck
11-26-2009, 10:43 AM
New U-joints too?
novadose454
11-26-2009, 11:06 AM
they were checked when the shaft was balanced.....
novadose454
11-26-2009, 11:07 AM
at least i guess they were checked....theres no noticeable movement on them...hey supershafts ....when you balance the drive shaft....universals are checked ...right?..
LongIsland63SS409
11-26-2009, 11:55 AM
ok...lets see how you guys can figure this one out...
at sixty miles an hour....im running smooth in overdrive.....steady sixty.....now lets say the road just levels out and the car freewheels....meaning the motor is going as fast as the car ...not acceleratiiing....and not having the motor slow the car....at that point...i get this vibration thru the drive train......rebuilt the rear...new bearings....double checked lash etc.......all good.....sent the axle to supershaft he balanced it....all good...bearings on the axles...all new....smooth.....called art carr he said that its not from the tranny.....could it possibly be the angle of the pinion...?? next thing to check...anything else..???? you tell me..

Nova,

Check the pinion angle.

At rest the pinion angle should be negative degrees. Under acceleration the rear rotates up (pinion rotates up). The pinion should be zero degreees under acceleration. A postive pinion angle could cause a vibration.

Check a cheap angle finder and crawl under the car a rest an see what the pinion angle is.

Does your narrowed rear have adjustable ladder bars or a four link?

Other might want to jump in?

http://www.2quicknovas.com/2qnpinions.html


Mike
novadose454
11-26-2009, 11:59 AM
nova,

check the pinion angle.

At rest the pinion angle should be negative degrees. Under acceleration the rear rotates up (pinion rotates up). The pinion should be zero degreees under acceleration. A postive pinion angle could cause a vibration.

Check a cheap angle finder and crawl under the car a rest an see what the pinion angle is.

Does your narrowed rear have adjustable ladder bars or a four link?

Other might want to jump in?

Mike

thats what i was thinking...yes..it does have adjustable ladderbars...so this is gonna be next on the list.... Thanks..
57tom
11-26-2009, 01:38 PM
make sure you have the right universal joint to match the rear end you have. I had a bad vibration on my 57 chevy at about 3500 rpm at 60 mph. my car has a dana 60 rear and had the wrong universal in it . I went nuts with changing everthing like you did.Marty was the one who found the problem.
novadose454
11-26-2009, 09:27 PM
right one ?.....if it fits ..its got to be right....
LongIsland63SS409
11-26-2009, 11:54 PM
thats what i was thinking...yes..it does have adjustable ladderbars...so this is gonna be next on the list.... Thanks..

Link to check pinion angle.

http://www.wolferacecraft.com/pinionangle.aspx


Mike
novadose454
11-27-2009, 08:58 AM
very helpful..thank you.......now i have something to do today.....lol.........
LongIsland63SS409
12-04-2009, 11:05 PM
very helpful..thank you.......now i have something to do today.....lol.........

Nova:

How did it work out?

Mike
novadose454
12-04-2009, 11:13 PM
well..i changed the pinion angle...and because im old and fucked up ...i brought it further down....a few degrees.. it vibrates at much lower speeds......well thats not it..but i see that it did make it worse soooooooooooo ....after rereading ...i see that with a solid ladderbar setup....which has no give really all heim joints..etc.....i need to bring it up almost to a straight line in with the driveshaft..or a degree down...soooooooo im gonna get under it this weekend..and we ll see if it solves my problem......hopefully it wont snow..