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1971 CDV - Vibration at HWY speed under load

Started by impalamansgarage, February 09, 2016, 03:21:23 PM

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savemy67

Hello impalaman,

Worn universal joints (or constant velocity Cardan Joints) could result in excessive bushing wear and excessive radial play in the output shaft.  However, since, generally, bushings are softer than driveshaft yokes and output shafts, it is more likely that any wear is confined to the bushings.  Since the transmission shop notified you of the excessive radial play at the output shaft, the transmission shop should be replacing several bushings, or they should be giving you the clearance measurements for the shafts/bushings affected by a driveshaft with worn u-joints, with the shop's assurances that the remaining bushings and clearances are OK.

The front of output shaft, at the flange, has a bushing that rides on the hub of the rear internal gear.  The output shaft is also supported by the case bushing, just in front of the governor and speedometer gears.  The driveshaft yoke slips over the splined end of the output shaft and the yoke is supported by one or two bushings in the tailshaft housing.  Clearances for the bushings should be on the order of .002 to .008 of an inch.  Bushings are not meant to support a great deal of weight or force - that is a job for bearings.  Bushings function as guides to control location and rotational movement.

If your transmission shop wants to charge extra to remove/replace bushings, I would anticipate maybe an extra $100 for the parts and labor.  Given that the shop noticed the excessive play, you should probably authorize this repair.

Respectfully submitted,
Christopher WInter
Christopher Winter
1967 Sedan DeVille hardtop

cadman56

Hello Impalaman,
I wrote about replacing the yoke from experience on (2) cars, a 1964 Ford Galaxy 500 & a 1991 Brougham dElegance.  Replacing the transmission output shaft bushing & drive shaft yoke eliminated the drumming vibration in both cases.  I only reply from experience.  A drive shaft shop should be able to locate & replace the yoke with no problems.  Have your yoke measured with a micrometer against a new one on the outside & check for wear ridges in the splines on the inside.  And check the splines on the output shaft of the transmission.  There is also a raised section in the center of the yoke that a spring loaded piece works on.  That should have been checked for wear ridges by the drive shaft shop too.
Good luck, Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

impalamansgarage

#122
Update: 
Transmission and driveshaft rebuilt. (The bushings in the tail shaft in the trans were shot.)
Passenger side engine mount replaced.
I replaced the drivers side mount and the trans mount a few weeks ago.

None of this has corrected the vibration.

I will bring the car home for a while and then maybe we will look at rebuilding the diff. Neither I nor the trans shop owner can hear and/or detect any
noise coming from the diff. After his test drives he "thinks" there might be an issue with the pinion shaft in the diff. We would need to tear it down
to see.

In the mean time I am going to install the smog pump removal kit from 500cid.com. Part number BL48.
That will at least make me feel a little better.

impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

Scot Minesinger

You will like the results of the smog removal kit, I did that on a 1972 Cadillac.  I found a 1970 alternator mounting bracket set too and was able to really clean it up.

Hope the differential rebuild clears it up.  Glad you got the trans fixed that needed it anyway.

When you do find the real problem, this will be one smooth nice Cadillac.  As I have probably written before, hunting down a problem like this has you fixing many things along the way that were just partially not 100%, and so when you get there with the right repair - wow is it nice.

Hang inn there and never give up.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

impalamansgarage

Quote from: Scot Minesinger on April 27, 2016, 07:54:13 AM
You will like the results of the smog removal kit, I did that on a 1972 Cadillac.  I found a 1970 alternator mounting bracket set too and was able to really clean it up.

Hope the differential rebuild clears it up.  Glad you got the trans fixed that needed it anyway.

When you do find the real problem, this will be one smooth nice Cadillac.  As I have probably written before, hunting down a problem like this has you fixing many things along the way that were just partially not 100%, and so when you get there with the right repair - wow is it nice.

Hang inn there and never give up.

Hanging with it like a rusty fish hook!
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

impalamansgarage

Quote from: Scot Minesinger on April 27, 2016, 07:54:13 AM
You will like the results of the smog removal kit, I did that on a 1972 Cadillac.  I found a 1970 alternator mounting bracket set too and was able to really clean it up.

Hope the differential rebuild clears it up.  Glad you got the trans fixed that needed it anyway.

When you do find the real problem, this will be one smooth nice Cadillac.  As I have probably written before, hunting down a problem like this has you fixing many things along the way that were just partially not 100%, and so when you get there with the right repair - wow is it nice.

Hang inn there and never give up.

Instructions say to remove crank pullies and balancer. Not sure why the balancer needs to come off. Took the crank pulley bolts out. Is the pulley suppose to slide off at this point? The factory service manual is confusing on this.
I took the cork out of the end of the crank.
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

impalamansgarage

A complete set of rear trailing arm bushings is on order. I plan to replace them this up coming weekend.
If this has no effect I will add a shim using 1/4 inch plate steel under the transmission mount.
The results of these two steps will determine whether I dive into the differential or not.

The quest continues.

This past weekend I added some 1.5 inch lift twist-in spring helpers in the rear coils. While the car was in the air I inserted them by hand. No tools
were required. With the car on the ground they offer only minimal additional lift and I was unable to determine whether or not the
geometry change they offered affected the problem.
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

Jon S

Quote from: impalaman on May 23, 2016, 03:44:37 PM
A complete set of rear trailing arm bushings is on order. I plan to replace them this up coming weekend.
If this has no effect I will add a shim using 1/4 inch plate steel under the transmission mount.
The results of these two steps will determine whether I dive into the differential or not.

The quest continues.

This past weekend I added some 1.5 inch lift twist-in spring helpers in the rear coils. While the car was in the air I inserted them by hand. No tools
were required. With the car on the ground they offer only minimal additional lift and I was unable to determine whether or not the
geometry change they offered affected the problem.

They may fall out with normal driving.  Have you considered air shocks?
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

impalamansgarage

Quote from: Jon S on May 23, 2016, 03:46:49 PM
They may fall out with normal driving.  Have you considered air shocks?

I took a long test drive. They stayed put. I will probably remove them soon anyway. The car rides well and the shocks seem to be fine.
I will replace them also. Might as well. No telling how long they've been in there.
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

Scot Minesinger

If you are replacing the rear suspension bushings, which is a great idea - have done mine too, now is the time to replace the springs and shocks too.  I use a set of spring compressors to replace rear springs, as the factory shop manual describes a crazy difficult method.  Also you need to sacrifice a small 1/2" wrench by bending it to make the tool needed to replace rear shocks.  The shocks and springs are not expensive (les than the cost of the 8 bushings for me anyway).
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

impalamansgarage

Quote from: Scot Minesinger on May 24, 2016, 07:24:21 AM
If you are replacing the rear suspension bushings, which is a great idea - have done mine too, now is the time to replace the springs and shocks too.  I use a set of spring compressors to replace rear springs, as the factory shop manual describes a crazy difficult method.  Also you need to sacrifice a small 1/2" wrench by bending it to make the tool needed to replace rear shocks.  The shocks and springs are not expensive (les than the cost of the 8 bushings for me anyway).

Good tip on the shock tool. Thanks!  I was thinking about using a long wrench to go in from the side over the frame rail but had not looked at it extensively as of yet. Bending a Harbor Freight wrench is not a problem!

My bushings came in yesterday. I ordered them from http://www.stylintrucks.com/. Go figure.
Tried rockauto.com but they were out of stock. A couple of other places wanted too much money. CaddDaddy.com wanted $150 per set. I received all eight for $106 from the truck website.

impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

impalamansgarage

Update:  Replaced rear springs, rear trailing arm bushings and shocks all the way around.

The shocks were shot.  :)

All this had no effect what so ever on the vibration and noise at highway speeds.    >:(

On the lighter side, the car rides wonderfully! Dead smooth like a Cadillac should. (As long as you stay below 50 mph)

Only thing left is to tear the rear diff apart and take a look at the pinion bearings.
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

"Cadillac Kid" Greg Surfas 15364

Mr Chevrolet,
I sure seems like you either got the first car off the assembly line after someone had a wild week end, or you have a built in gremlin.  You have been chasing ghosts for a couple of months seemingly without much success at anything other than spending money for repairs that don't seem to correct the problem.
What I am going to suggest might seem sacrilegious to some on this forum, but it seems the information you have received although worth the price you paid for it did not get you the results you want.
I would suggest you start at your local Cadillac dealer, and if they cannot help you try another "high end" dealership.  Ask them to diagnose your issues (for pay).
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-

impalamansgarage

#133
Quote from: "Cadillac Kid"  Greg Surfas 15364 on June 01, 2016, 01:42:48 PM
Mr Chevrolet,
I sure seems like you either got the first car off the assembly line after someone had a wild week end, or you have a built in gremlin.  You have been chasing ghosts for a couple of months seemingly without much success at anything other than spending money for repairs that don't seem to correct the problem.
What I am going to suggest might seem sacrilegious to some on this forum, but it seems the information you have received although worth the price you paid for it did not get you the results you want.
I would suggest you start at your local Cadillac dealer, and if they cannot help you try another "high end" dealership.  Ask them to diagnose your issues (for pay).
Greg Surfas

Not a bad idea at this point. However the diff is the only thing in the drive train which has not been touched..... other than just changing the fluid.
impalamansgarage
https://www.youtube.com/c/impalamansgarage
1971 CDV (http://bit.ly/1QylevA)
1981 CDV (Sold)
1992 SDV (Sold)
1963 Fleetwood (Teenage Junker Project - Sold)

Jon S

Quote from: "Cadillac Kid"  Greg Surfas 15364 on June 01, 2016, 01:42:48 PM
Mr Chevrolet,
I sure seems like you either got the first car off the assembly line after someone had a wild week end, or you have a built in gremlin.  You have been chasing ghosts for a couple of months seemingly without much success at anything other than spending money for repairs that don't seem to correct the problem.
What I am going to suggest might seem sacrilegious to some on this forum, but it seems the information you have received although worth the price you paid for it did not get you the results you want.
I would suggest you start at your local Cadillac dealer, and if they cannot help you try another "high end" dealership.  Ask them to diagnose your issues (for pay).
Greg Surfas

I seriously doubt any Cadillac dealership has mechanics familiar with a 1971 Cadillac.  I think Impalaman has approached the problem properly and is down to the last variable.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

jenasp

Hello. I went trough the same procedure as you with my -58 a few years ago. It turned out to be the water pump hub not being exactly centred on the shaft. Try simply removing the fan and se if it makes a difference.

Scot Minesinger

Yes, I'm thinking the Cadillac dealership will do more harm than good.  It understood that the idea is find an experienced mechanic who is capable of determining the problem and pay to find the problem.  If someone of this caliber exists and is trusted, it might be a good idea.

There is a procedure in the shop manual to eliminate vibration, and it is presumed this has been followed and exhausted.  The water pump issue would surface with car in park and racing engine with belt on and off (following procedures so it does not overheat).  I fixed a 1975 Caddy that suffered a similar problem following shop manual without leaving the garage to diagnose and repair.

Bushings not properly pressed into the four rear control arms will cause a vibration, presuming that was done correctly and it is not the problem.  The only thing remaining is the rear differential - just about.

One of my friends suffers a vibration at high speed and it has been diagnosed to be the drive shaft universal joint gone bad.

Keep us posted.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

"Cadillac Kid" Greg Surfas 15364

Vibrations are vibrations and believe it or not new cars just off the assembly line sometimes have them./  One of the most important positions in the "get ready" line of a new car dealership is the person or people that take these cars for a final test drive to find anything that is amiss.  Usually thes are the most experienced, older mechanics that have been doing this for decades.  There is nothing mysterious about a noise or vibration if you know what you are doing and have done it your entire career.
Just my thought.
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-

cadman56

Please stay out of any Cadillac dealership.  Two examples:
1:  A local club member with a 69 deVille convertible went on a multi region tour to west Texas.  He had problems so took it to a local Cadillac dealor.  Cost him a fFORTUNE for tires, shocks & brakes & it took them almost three months to fix it.  All parts are standard off the shelf GM parts.
2.  I lost the speedometer, convertor lockup & cruise in SW Colorado in my 91 Brougham.  The local Cadillac dealor told me to not even bring it in to them.  Had to drive it all the through mountains to central KS with no speedometer & OD.
One question, does your car have the inner pipe inside the front exhaust pipes like some Chevys did in the 70's?
Good luck, you have been through the mill on this one.
Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

TJ Hopland

Would that inner pipe cause a vibration?  I would think that would be more of a rattle issue?   I remember the original exhaust on my 73 had that double wall pipe in places. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason