67 Deville crazy vibration, help - NOW FIXED

Started by TomB, September 15, 2022, 09:14:20 AM

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TomB

Over the last two months my deville developed a nasty vibration. Wheels balanced, rims checked but no difference. Bushings and seal replaced in the transmission tail, but vibration worsend. Driveshaft has no damage, no lead on the driveshaft seems to have fallen off. Could it be that the front universal joint is worn out?

These double universal joints seem hard to replace. They show a tiny bit of play, really barely any. But could this me case or am I missing a possible culprit.

See pic.

Thanks

"Cadillac Kid" Greg Surfas 15364

You are on the right track thinking drive shaft. The Cardan joints wear and the first sign (in my experience) is vibration.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

TomB

#2
Thanks Greg. The shop manual says that the cardan is serviced as a whole, which I interpret that moving parts cannot cannot be replaced by an amateur (u joints, center ball) ....or can it?

Thanks

Dave Shepherd

Back in the day GM did not repair these shafts, replace only. Pretty sure there are now overhaul kits for this job. A good HD truck shop is your best bet to do this repair.

V63

I have rebuilt them before as replacing the ujoints, the originals are plastic injection retainers and replacements use standard metal clips. I would not hesitate doing it again as not that bad.

Be sure to Grease the little ball and socket.

The Tassie Devil(le)

#5
There should be no Lead on the drive shaft, as any balancing was done with steel weights welded to the shaft tubing.

What is the bushing like in the transmission extension?   Can you move the front slip yoke up and down or sideways?

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

TomB

I can feel some play sideways in the front joint, also shown with the highspeed camera footage. The rear couple seems solid.

TomB

Both bushings in the extension are new, very tight, no play anymore there.

TomB

With a hi speed camera it seems that the cardan/driveshaft is still wobbling even though the transmission tale bushings are new with a nice tight fit. By the way the seal and bushings from rockauto did not fit at all; did cost me quite sum to have them sent to Europe, rubbish.

I ll have both sets of universal joints rebuilt locally, including center balls and springs etc. Really hoping that it will resolve the vibration as it will costs me well over 1000$. Vibration starts at 30 Mph and disappears over 70 Mph.

Praying that J.'s assessment is not gonna haunt me....

Have a great weekend y'all.

Tom

fishnjim

Chasing these vibration issues can drive one "mad". 
One good clue is the tail shaft bushing and seal was damaged.  Instead of thinking it was "bad", think about what caused it to wear excessively and how related.  It was possibly receiving too much "movement".  Probably from running it "out of balance".   Anything this old will have some issues related to lack of lube and aging rubber parts, so best to replace as much as you can afford.  These "keep it original" thinkers are not using good maintenance principles.
A rotating shaft has a "harmonic" point based on rpm.  If you run it there long enough it'll self destruct.  It's like sound waves that reinforce each other increasing amplitude but it's vibration frequency.  So I'd suspect it's related to the prop shaft or drive line or drive shaft what ever you call it where you're from. Treat it as a system.  I'd also look at the differential and make sure the other end is good.  That seal/bearing could be next, if you continue to run it as is.  The more play the more movement that can happen. 
Ball joints usually are associated with steering issues; wandering or wobbling/fluttering.   They might be related from the "movement" category but not a bad idea to replace if they're origs and this old.  They can be checked with a tool that's put under the tire lifted slightly off the ground and checked for play.  I don't think the alignment computer jockeys have ever seen that technique.
ps: You have to go back to the original part lists and bring the numbers forward to make sure you get the right parts.   This was all on paper in the day and wasn't put on the computer til '84-ish, so there's likely mistakes and miss info.   I'm not defending/protecting RA, just telling you how it is and how to avoid wrong parts, if shipping costs are an issue.   Some of us keep the paper records so we don't get in that computer trap, but getting scarcer like other period things.  There would be "old timey" trans people here that would know the correct seal numbers from memory having changed them.  They too are getting scarcer.  These were very good transmissions and highly sought after.

cadillactim

Might want to make sure your harmonic balancer or a bad tire are not contributing to the problem.

First thought is driveshaft, then maybe a bad tire (vibration in steering wheel = front tire, vibration in seat = rear tire), then harmonic balancer.

I had a noticeable vibration once that started after I replaced the tires. Had tires checked, balance checked. Everything seemed fine, but vibration remained. Finally just lived with it. In time tires needed replaced. Once I did that vibration disappeared!

Point being just because tires check out okay one could still be bad.

Tim
Tim Groves

TomB

Thanks Tim, driveshaft is being serviced. If this is not resolving the issue will move on to tires.
Have a great day.

James Landi

Two related experience '61 convertible... cracked flex plate "ears" where the plate bolts to the flywheel--vibration occurred at seemingly random speeds... (can be checked by removing the underside bell housing inspection plate)-- quick fix: spot welded.  The other occurred on my '67 Eldo--- a shake in front end at certain speeds-- after chasing down a bunch of expensive parts replacements, the problem turned out to be a slightly bend tire rim.  Was discernable when the car was on a lift and in gear.   Perhaps my experiences will help.   James

Steve Lomas

I had a wobbling vibration that usually only appeared>55 mph then got dramatically worse with speed on a 75 Eldorado.

I exhausted every possibility I could think of and pretty much gave up. But I noticed it was often worse or better after turning at intersections, and then that it was worse driving into the wind than away from it.

Turned out the hood was wobbling, almost imperceptibly to look at at, but enough weight in that hood to feel it shake the whole car- a couple of rags on the rubber stops fixed it instantly.

Always the last place you look as they say!

TomB

It was quite a job, but it is fixed. It did cost me a little fortune but the driveshaft of my deville 67 is better than new. No more vibration, she floats extremely smooth now. I have attached a bunch of pictures that are hopefully useful to someone. As you can see in the pictures, all the moving parts were in a deplorable state, probably bone dry and rusty. When I started driving it after 20 years in a barn I probably quickly grinded al the joints to pieces. The shaft is better than new now: solid fixture of the center balls, perfect alignment, sturdier welding at the shaft.
Enjoy the pictures. Tom


Roger Zimmermann

It seems that the drive shaft was in a bad condition; no wonder that you had vibrations!
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

fishnjim

I hope everyone reads this that's contemplating resurrecting a "sitter" on owns one that sits.
The temptation is to get it going as quickly as you can.  It's for lack of a better word a "macho" thing - demonstrating prowess to some.  That's looking for trouble, if not then but down the road.
Even if it had grease after 20 years, grease solidifies and flakes off or worse packs and has no lube property.
Seals failure is likely a sign of underlying bearing/bushing issues. 

I keep harping on it, but check each system out before you start-up and drive.  Not only cost, but your life may depend on it, if the brakes fail or something catastrophic breaks. Even if it's "running" isn't for sure.   I was surprised myself how bad the '58 "driver" was when I got it.  I saw a '55 "Ch" drop a drive shaft from the front at the dragstrip and it whipped around and dug in the pavement and launched the car like a catapult.  Things happen.   Noise is just a symptom.

Dave Shepherd


skinny_tom

Quote from: TomB on October 16, 2022, 05:34:12 AMIt was quite a job, but it is fixed. It did cost me a little fortune but the driveshaft of my deville 67 is better than new. No more vibration, she floats extremely smooth now. I have attached a bunch of pictures that are hopefully useful to someone. As you can see in the pictures, all the moving parts were in a deplorable state, probably bone dry and rusty. When I started driving it after 20 years in a barn I probably quickly grinded al the joints to pieces. The shaft is better than new now: solid fixture of the center balls, perfect alignment, sturdier welding at the shaft.
Enjoy the pictures. Tom



Thank you for posting your pictures and the results. Getting specific information about parts that are called to be "replaced as a unit" in the shop manual are no longer available as a unit. I've been curious about the assembly and it's construction. Mostly about how to grease mine after sitting for 25 years. Doesn't look like there is any "real" way to get it done without disassembly.

No vibrations or noise so far... (fingers crossed)
- Tom -
1965 Eldorado