Demons got "VIBRATIONS"
#436068
08/12/09 07:33 PM
08/12/09 07:33 PM
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Joined: Mar 2007
Posts: 12,011 Finally a HUSKER again
Moparnut426
OP
I Live Here
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OP
I Live Here
Joined: Mar 2007
Posts: 12,011
Finally a HUSKER again
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So now that the car is moving, and I have things moving in the straight and narrow. I have been driving the car more, and working out heating bugs, tuning bugs, and I had a vibration, well still do. I bought a new driveshaft because the one in there was a homemade cobbled up shaft. The engine was balenced with damper, flywheel, but not clutch. I have an 833 that was well used. At higher speeds I get a pretty bad vibration, I mean verry noticable speed related vibration. Driveshaft is new, gears are new 3:91s. I balenced the wheels/tires 1.5 years ago when boughten. What could be the problem guys. I know I have been on here a lot lately, but you guys have been pretty spot on on everything so here is another one for ya.
Kasey
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Re: Demons got "VIBRATIONS"
[Re: rowin4]
#436074
08/12/09 09:10 PM
08/12/09 09:10 PM
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Joined: Feb 2005
Posts: 20,185 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,185
PA.
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If you changed anything in the rear suspension recheck your pinion angle. 25+ years ago I put super stock springs on the rear of my 72 duster. I had a high speed vibration and went crazy trying to find it till I read about pinion angle. When I changed the springs my pinion angle ended up at 5-10 degrees nose up. I lowered the pinion back where it should be and the vibration was gone.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Demons got "VIBRATIONS"
[Re: Moparnut426]
#436077
08/12/09 10:09 PM
08/12/09 10:09 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
So now that the car is moving, and I have things moving in the straight and narrow. I have been driving the car more, and working out heating bugs, tuning bugs, and I had a vibration, well still do. I bought a new driveshaft because the one in there was a homemade cobbled up shaft. The engine was balenced with damper, flywheel, but not clutch. I have an 833 that was well used. At higher speeds I get a pretty bad vibration, I mean verry noticable speed related vibration. Driveshaft is new, gears are new 3:91s. I balenced the wheels/tires 1.5 years ago when boughten. What could be the problem guys. I know I have been on here a lot lately, but you guys have been pretty spot on on everything so here is another one for ya.
Kasey
You say SPEED related so that leaves the clutch out or you could bring the engine RPM up and it would occur.... I would have the tires and wheels balanced first... you need to start eliminating things, doing the easiest first
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Re: Demons got "VIBRATIONS"
[Re: rowin4]
#436078
08/12/09 10:36 PM
08/12/09 10:36 PM
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Joined: Mar 2007
Posts: 12,011 Finally a HUSKER again
Moparnut426
OP
I Live Here
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OP
I Live Here
Joined: Mar 2007
Posts: 12,011
Finally a HUSKER again
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Ok, the rear end has everything new. I rebuilt the center, and it has green bearings. The Tires are definatly not flat in spots, I make sure if it does set its off the ground. The only thing Im thinking is the rearend is out of a truck, and I cut and moved the pads 10 years ago before I even knew what a pinion angle it. I know I measured before and after when putting them back on, but I was 16 years old ish when I did it. Im going to check that first. Then I might take my wheels in and ballence them again. It definatly rear oriented.
Also I just got done putting a new yoke in the rear from Mancini, its the nice billet steel one. Sooooooo, new shaft, rebuilt tranny, new gears, new rear bearings, new u joints, new output bushing, new front yoke, new 11" rear drums, new green axle bearings, and I did exactly what mopar told me on measuring my shaft. I had vehicle weight on cal, measured from 1 inch from bottoming out in tail shaft, and to the center of the rear yole. Center to center was 49 3/8 ish.
Im hopeing on the pinion angle... Thanks guys
Kasey
Last edited by moparnut426; 08/12/09 10:42 PM.
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Re: Demons got "VIBRATIONS"
[Re: Moparnut426]
#436087
08/13/09 11:30 PM
08/13/09 11:30 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
so my pinion angle is 0, maybe 1 posotive, my floor is reading 0, my rearend reads the same at my pinion flange. thats bad, and probably my vibration, or what my dad calls knuckle knock.
kasey
The floor has NOTHING to do with checking the pinion angle.... there are 2 theories how to check it 1) take a reading from the tailshaft output then read the pinion, it should be about 5* down from the trans number(for a left set up) 2) read the drive shaft and put the pinion 5* down from that(easy way to do this one is to use a socket that fits the U-joint cup then use the inclinemeter/ angle finder on the socket then read it, now turn the driveshaft 90* and do the same thing, the difference is angle)... this is done with the car weight on the diff but it can be up in the air... both front and rear
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