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PINION ANGLE

XMAN JR

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Working on my dads 62 polara & I noticed a vibration when I would start it. So I took the drive shaft & got it balanced. The guy said it was out but not that bad. I put it back in & the vibration is still there. I checked every thing. The rear that's in the 62 is out of my dads 67 gtx. We drove the gtx & it ran fine no vibration. Now a friend of mine says it has to be the pinion angle. Why would the pinion angle change from one car to another ?
 
Think the rear axle is 20" from the front spring eye on a 62 vs 22" on a 67. Maybe that would affect pinion angle?
 
KryslerKid could answer the question in post #2. He's on your other thread.
 
2" difference in wheel base shouldn't cause much if any. Are there any other changes like ride height etc? Even using air shocks back in the 60's and raising the car 3-4" inches didn't do it but with a change in WB and ride height might....
 
Have you measured the driveline angles? The pinion can change with acceleration/deceleration so the vibration should change with that too. It also may come in at a different RPM that a unbalanced driveshaft. I would not think a swap would result in a change, up down or side to side, but I would check them.
 
KryslerKid could answer the question in post #2. He's on your other thread.
Yes they're 20" but that wouldn't effect the angle. The placement of the perches would though. I've never known anyone having problems swapping the newer housings for the exception of them being wider.

Pinion angle should be pointing upward to some extent, not level while sitting flat on the wheels.

Are you still useing the trunnion joint driveshaft? (Still trying to figure out what trans you're useing that doesn't have a kickdown leaver)
 
Yes they're 20" but that wouldn't effect the angle. The placement of the perches would though. I've never known anyone having problems swapping the newer housings for the exception of them being wider.

Pinion angle should be pointing upward to some extent, not level while sitting flat on the wheels.

Are you still useing the trunnion joint driveshaft? (Still trying to figure out what trans you're useing that doesn't have a kickdown leaver)
This (older ) stuff is all new to me. What do you mean trunnion ? Its the bolt on drive shaft. We didn't change anything on ether car. We just swapped rear ends. The 62 is on jack stands. The front is on the frame & the rear is on the housing. We never drove it. I notice the vibration as soon as I start it.
 
This (older ) stuff is all new to me. What do you mean trunnion ? Its the bolt on drive shaft. We didn't change anything on ether car. We just swapped rear ends. The 62 is on jack stands. The front is on the frame & the rear is on the housing. We never drove it. I notice the vibration as soon as I start it.

Not sure I follow. The vibration occurs when you start the car? Car is on jack stands correct? At what speed does the vibration occur? Can you unbolt the driveshaft at the trans end and run the car without the driveshaft in to duplicate the vibration? Have you rotated the wheels?
 
This (older ) stuff is all new to me. What do you mean trunnion ? Its the bolt on drive shaft.

20170913_194942.jpg
 
MMM I will have to check into that. Did you put them between the leaf springs & the perches ?

Between the perches and springs.
I bought an angle gauge and checked the pinion ujoint angle against the transmission flange. The pinion was pointing down farther than the transmission was pointing up.
 
Not sure I follow. The vibration occurs when you start the car? Car is on jack stands correct? At what speed does the vibration occur? Can you unbolt the driveshaft at the trans end and run the car without the driveshaft in to duplicate the vibration? Have you rotated the wheels?
Yep that's the drive shaft. I took the rear wheels off & still does it. It vibrates at idle & even worse when I give it some gas.
 
Yep that's the drive shaft. I took the rear wheels off & still does it. It vibrates at idle & even worse when I give it some gas.

It does it in neutral? If so, wrong balancer for your crank, wrong converter or aftermarket flexplate for your crank. I think you mentioned you checked your tc bolts.
 
Vibration at idle might be motor mounts or an engine issue. Pinion vibration on mine occured while driving when torque was being applied or let off.
 
I don't think there is any way pinion angle or driveshaft will cause a bad vibration at idle.

Pull the driveshaft off and run the engine without it attached. I think Kid is right on the TC, flexplate or even harmonic balancer being wrong.
Is this a poly 318? Steel crank, internally balanced. If you have a balancer from a newer 318 it is possibly for external balance applications. Same with flex plate. TC is 19 spline and should be correct.
 
The engine is a 413 max wedge. My dad just had it built. Our engine builder ran it on the dyno several times. The trany was just rebuilt also. I will take the time today & pull the drive shaft. I will let you guys know. I will also measure the between the rear & trany again. Loaded & unloaded
 
Yep that's the drive shaft. I took the rear wheels off & still does it. It vibrates at idle & even worse when I give it some gas.
If it does it sitting still you can rule out the driveshaft, rear end, etc. It could be the torque converter, bad mounts, harmonic balancer, badly out of tune engine, etc... dig in! Unfortunately vibrations can come from many things so it's a process of elimination just like it vibrating while sitting still eliminates any part that isn't moving.
 
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