Vibration hunt in my '64 Galaxie

[Lenz]

445's running great, took it out on the local back street and was immediately rewarded with a "buzzy" vibration through the shifter, much more noticeable on deceleration.  Coasting 25-30 mph with the drivetrain unloaded feels as though the driveshaft is the culprit, the vibration turns into an out of balance feel, or whip.

Pulled the driveshaft and took it in for balance check today.  Trans is a toploader, new seals and gaskets along with a fresh tail shaft bushing.  The trans internals "look" good, and the magnetic plug showed a slight amount of gray metallic matter but nothing substantial.

What I'm wondering about along with the driveshaft balance is the amount of end play that should be present at the end of the tail shaft when it's not supported by the yoke, bushing or seals, and then also if you should be able to get any lateral movement at the yoke with all parts assembled.  I'm picturing a possible wear problem on the inboard end of the tail shaft.

There is no vibration associated with the clutch and input shaft operation, gotta be on the move to feel it.

Sorry if this comes across confusing, just trying to sort out possibilities.

[65er]

 Out of balance issues seem to show up at higher speeds like 50+ mph.  Mine was coming on strong about 58 and made the inside of the car rumble.  Turned out to be an out of balance pinion yoke for the most part.  Since yours happens at such a low speed it sounds like you may be having a driveline angle issue.   Since you say it's worse on decel, my first thought would be that the pinion angle may be too low.

Has the vibe been there long, and have you changed anything that could affect the angles?  Engine/trans mounts, had the engine out etc or obviously pinion angle adjustments.

[ScotiaFE]

Ah the good old vibration. 
The Top Loader sounds fine to me. It will have just a bit of wiggle on the out put if you pinch it with your fingers and wiggle it.
The other end is supported by a ball bearing and unless the bearing is shot it should be fine.
As Wade said the deceleration may be pinion angle, but as with all things Hot Rod you have new HP stuff hooked up to
50 yr old stock stuff. Yes, No, maybe?
Things I would look at.
Drive Shaft. Get the best one you can fine with the biggest u joints and the fastest balance you can get. The Gal has a long one
so you want the biggest diameter you can stand looking at. Aluminum ain't so bad either.
All that 50 yr old rubber(?) in and around the springs to make for a soft cushy ride is not helping either.

[Lenz]

Yes, lots of stuff came out and went back in, much new.  The only thing untouched in the driveline is the rear end (and that does have air shocks on 5 leaf springs.  I can play with that to change angles a bit to see if there's an improvement, give me a direction to go.)  I was wondering why there were flat washers stuffed between the motor mounts and perches when I took the old 390 out, this might be why.  The cross member and motor/trans mounts are stock style pieces.  Also, there was a 3 spd overdrive in it, but those are dimensionally the same as a toploader where mounting is concerned.

Guess I'll make sure the driveshaft is balanced first.  It also is new with 1330 joints.

[Ratbird]

I had a vibration I couldn't find a while back. Eventually I found it, it was the transmission cross member. The tack welds that held the seam together had given out and the bottom piece was bending down about a 1/4 inch. It was basically just very unstable. Clamped it back together and welded it all the way across. No problems since.

Dave

   

[Lenz]

Thanks Dave.  That's another plus one for driveline angles and driveshaft harmonics.  I'm picking up an inclinometer today to verify angles at the trans tail shaft and pinion yoke. 

Found clear basic information on how to set these up, what angles they should fall within and how they relate to each other to cancel out the vibration caused by U joint operation.  If that's the source of my problem (at this point it seems likely) then I'll shim accordingly to resolve the issue.

Don't have my driveshaft back yet, I still wanted to make certain that's well balanced first.

Gotta get this done though, I'm itchin' to get to the enjoyment phase of this project and I'm at the door.

[Drew Pojedinec]

Driveline angles.... folks could debate these for years on a forum.

for myself with a 63.5 Galaxie:
Pinion and trans yoke parallel, angle to driveshaft 3.5 degrees.  Runs smooth as could be under all usage.  I tried several different angles and like this the best.  Just like setting the timing on an engine, I think driveline angle is vehicle specific, something that needs a lil trial and error until you find what works best for you.

[Drew Pojedinec]

Len....
If you are interested, pm me, I'd be willing to loan a tool if ya need it for a month or two:
http://www.summitracing.com/parts/sps-64225/overview/

[Lenz]

Driveline angles.... folks could debate these for years on a forum.

for myself with a 63.5 Galaxie:
Pinion and trans yoke parallel, angle to driveshaft 3.5 degrees.  Runs smooth as could be under all usage.  I tried several different angles and like this the best.  Just like setting the timing on an engine, I think driveline angle is vehicle specific, something that needs a lil trial and error until you find what works best for you.

Thanks for the numbers Drew, good stuff to set up to.  As you say, may need to tweak from there but so be it.  PM sent this morning-
Len

[machoneman]

http://www.fordmuscle.com/archives/2000/06/vibrations/

Lots of analysis charts/texts available on the Web. Just Google some variations of drive or driveline vibrations. Funny too in that it's often the darned simple things that cause a majority of vibes.

[Lenz]

Well, here we are, 10/1 and I'm finally running . 

Had the the car apart and back together in various stages don't know how many times since I started this thread.  Three things came to light:

1.  The transmission needed a rebuild which was tackled first, shaft wear and bearing issues to be expected in 50 year old parts.  Shout out to GJCAT427 for doing the wrenching for me after I collected the parts from DKT and messed with other stuff.

2.  The driveline was not correctly set up relative to parallelism of the tailshaft to pinion flange.  Thanks to Drew P for sending up his angle finder, saved me $100 for a tool I'd probably rarely if ever use again.

3.  The biggest issue discovered beyond the above was that my new driveshaft was not cutting it.  After the above repairs the vibration remained to a lesser degree but still way too much to ignore.

Enter a new driveshaft from CCI driveline in Michigan reputed to be good to 7,000 rpm.  Don't mind sayin' I was holding my breath while running it up through the gears, but that new driveshaft finished the job.

Smooth as silk .  Well, 50 year old silk anyway, got lots left to do.

 

[turbohunter]

Congrats Len
That's gotta feel good.