1965 satillite rear axle vibration

[swampdonkey]

Hello gentlemen

I need opinions before cut of my leaf spring perches to relocate the pinion angle. I have had a hard vibration for awhile and I want to get it fixed. I checked the angles of the rotating assembly and found the motor and tranny
to be 2 degrees facing down on the tranny tail end, the drive shaft at zero, and pinion angle facing up almost 2 degrees. I put in a #4 brass shim and most of the vibration is gone. The rear axle housing is a 489 case not sure what car it came out of but, Im sure not the original to this car. Question is I thought they were all pretty much set up the same from the factory 5 to 7 degrees facing down. New hemi leaf springs installed few years ago.

 

[747mopar]

Sounds like it was close to begin with? Angles should run parallel to one another but you may need the nose tilted down a bit to compensate for spring windup. If it's the pinion angle you can usually determine which way it's off by the vibration. If it does it under low load or coast it usually needs to go up but if it only does it under hard acceleration then it's likely to high already.

 

[lewtot184]

when i put my 65 coronet together i noticed a vibration around 50-65mph. i did all kinds of things, including shims, and none of it worked. i did find that my driveshaft was out of balance and the u-joints must be kept greased. no more problems! something else to think about is the way the engine and trans sits in the chassis on the early b-bodies. both are angled towards the driver side along with the typical 2 1/2" offset. is drive line angle already figured into the design making the rear axle shim process unnecessary? i think so. i think my pinion angle is around 1 or 2 degrees at most and it works well.

 

[66Satellite47]

Sure seems like a driveshaft issue. A big quality driveshaft is the best investment you can make. I broke one at 112 MPH, no good! Check your pinion angle, but that would not make much vibration difference. Driveshaft or tires.

 

[swampdonkey]

For some reason I can't add anymore information with photo's on this thread my computer freezes. well anyway with the perches level on the jack stands the pinion angle is 2.5 degrees facing up. When I turn it down to 7 degrees the perches look way off. I am kind of holding of relocating the perches until I get a clear understanding of what is going on here. 489 case in a 1965 satellite with new motor and tranny mounts, drive shaft newly balanced. tires and rims spun balanced should not be vibrating. Any Ideas?

 

[miller]

Spring perches are mounted on the housing parallel with the centerline of the gear case. Is that how you have it? But, both front and rear spring hangers, and the springs themselves affect the resting angle of the axle housing, once all mounted up.

Just things to consider. Engine/trans mounted sets that angle, at the front of the driveshaft. Should be slightly higher than the rear axle...that's what sets the driveshaft angles front and rear that's needed to knock out vibration. Just saying look at the whole picture. Good luck on it!

 

[MD Mopar]

did you check the front spring hangers? I changed my springs to super stock springs and changed the front hangers. I also had a vibration after I did this change. The supplier sent me spring hangers for a 65 dodge, which are 1" longer than needed for a 65 Plymouth. Therefore the driveshaft was pulled out further and caused my vibration. Drove me crazy for years. Just a thought. good luck.

 

[lewtot184]

that's the same springs i run. all that shim may be good for a hard biting drag racer but i don't think it works good for driving. still think it's driveshaft or u-joints. i had a shaft made for my '65 using 7290 joints. always vibrated. finally took it back to the guy who made it and he proceeded to tell me nothing was wrong with it,...lol. got the shaft back and the car drives remarkably better (mr. perfect fixed something,...lol). i also started using a heavier tacky grease in the u-joints and think that helps a little.

 

[65RoadRacer]

For those who aren't aware, we did an article on the Tremec toolbox smartphone app, which includes a driveline angle finder. I've used it and some of the others.

 

[Jcharger]

I apologize if I missed the answer to at what RPM the vibration occurs and whether it occurs equally on acceleration or deceleration. My understanding is that pinion angle issues show up as vibrations (often at different conditions than an unbalanced driveshaft which can occur in the 50 mph range) that are more pronounced going up or down hills or under different acceleration/deceleration conditions. I have a similar issue that shows up at 70-80 mph.

As has been said above the tail of the transmission and the nose of the differential should be parallel with the differential pointed down a little to compensate for twisting. Usually the differential is lower than the tail of the transmission. My car, like yours has the opposite geometry.

One issue I have not seen discussed is the side to side pinion angles, and assume these should line up.

Regarding pinion angles, it may be possible to shim the transmission up a little. If not, you may be able to drop the engine and K member with shims, but I think this is a bigger project and have not done that.

 

[swampdonkey]

I apologize if I missed the answer to at what RPM the vibration occurs and whether it occurs equally on acceleration or deceleration. My understanding is that pinion angle issues show up as vibrations (often at different conditions than an unbalanced driveshaft which can occur in the 50 mph range) that are more pronounced going up or down hills or under different acceleration/deceleration conditions. I have a similar issue that shows up at 70-80 mph.

As has been said above the tail of the transmission and the nose of the differential should be parallel with the differential pointed down a little to compensate for twisting. Usually the differential is lower than the tail of the transmission. My car, like yours has the opposite geometry.

One issue I have not seen discussed is the side to side pinion angles, and assume these should line up.

Regarding pinion angles, it may be possible to shim the transmission up a little. If not, you may be able to drop the engine and K member with shims, but I think this is a bigger project and have not done that.

Thanks for all the information I have now some troubleshooting to do we will see how things measure up