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1956 Front end shake

Started by jgreene, December 03, 2017, 01:37:04 PM

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jgreene

I have a 1956 Fltwd 60 Special.  The entire front end has been gone through, the steering box rebuilt, front coils replaced, one of the rear leafs re-arched(both sides) to get the rear end to the correct height.  The front end, over good sized dips, has a kind of a shake to it.  I have not driven another 1956, so I don't have a comparison.  I have a 1950 and it does nothing like this.  I have not replaced the shocks because they are not leaking, but that may help.  Is this something inherent to 1956's?
At the same time of the front end shaking, the windshield also rattles and shakes.  I have put a lot of sealant in there and it has not helped.
Thank you
Jim Greene
Jim Greene

carguyblack

Jim,
I have had 3  -1956 Cadillacs over time and I have not really had one that I felt "rode like a Cadillac". I have the same symptoms you experienced after replacing the front end components and tires. The windshield sound you notice is what really inspired me to post. When I've hit a road bump and the windshield makes that chirp, it's like I have no rubber or cushion in the front end. Yet, it's all seemingly fine. Can't seem to get that ride I would have expected for a car of this era and weight. I'd be very interested in others who own this year to weigh in. I've just grown used to it and am OK as long as the car tracks properly and I get the seal of approval from the alignment/suspension experts.
Chuck
Chuck Dykstra

1956 Sedan DeVille
1956 Coupe DeVille (2 sold)
1957 Oldsmobile 98 (sold)
1989 Bonneville SSE

Lexi

#2
I also have had three 1956 Cadillacs and none of them ever did that. They can sound a little noisy and "rattly" when hitting hard bumps in the road. I just had my entire front end rebuilt and while a little "tighter feeling", it is perhaps marginally less noisy. I realize that this sounds elementary but have you checked your tires for balance (or for just a bad tire), even though they may be new and not suspect? Or possibly a weight has come off (though prior to such the wheel ran true), or a slight bent/over flexing rim due to age or incorrect load range applied? Perhaps those more knowledgeable than I can comment but is it possible that say a specific type of tire issue may only reveal itself when at speed with a load on it (i.e. under the weight of the vehicle)-and not manifest on a balance machine? As a long shot you may want to also check your body mounts for tightness. A buddies frame off project recently discovered all the bolts needed re-torquing. Car ran tighter and quieter after that. Let us know what you find to be the problem. Clay/Lexi

J. Gomez

Jim,

Quote from: jgreene on December 03, 2017, 01:37:04 PM
I have a 1956 Fltwd 60 Special.  The entire front end has been gone through, the steering box rebuilt, front coils replaced, one of the rear leafs re-arched(both sides) to get the rear end to the correct height.  The front end, over good sized dips, has a kind of a shake to it. 

Since you already touched most of the major components on the front end, just a few more.
Have you made the adjustments to the steering connecting links?
How are your tied rods and idler arm?
Have you gone through the bottom and lower “A” arms?
Did you check the kingpins on both side?

Quote from: jgreene on December 03, 2017, 01:37:04 PM
I have not replaced the shocks because they are not leaking, but that may help.

Replacing the front shocks would be my first guess cheap and easier before tackling the other items on the front end.

Quote from: jgreene on December 03, 2017, 01:37:04 PM
At the same time of the front end shaking, the windshield also rattles and shakes.  I have put a lot of sealant in there and it has not helped.

Hmm if the windshield rubber seal is properly set and sealed it should not rattle and/or shake unless the seal is not properly seated in the frame or the glass is not seated on the seal grove. ???
J. Gomez
CLC #23082

carguyblack

Clay, Jose, and Jim,
Sure would like to replace something that needs it, but everyone is saying it's all fine. On the one 1956 I now have, I've not done the king pins as it wasn't suggested. What is the definitive test if the kings need replacing?
Chuck Dykstra

1956 Sedan DeVille
1956 Coupe DeVille (2 sold)
1957 Oldsmobile 98 (sold)
1989 Bonneville SSE

J. Gomez

Quote from: carguyblack on December 03, 2017, 03:16:09 PM
Clay, Jose, and Jim,
Sure would like to replace something that needs it, but everyone is saying it's all fine. On the one 1956 I now have, I've not done the king pins as it wasn't suggested. What is the definitive test if the kings need replacing?

Chuck,

The only test I’m aware for the kingpin or steering knuckle is to lift the front wheels and holding the wheel on top and bottom and rock it and hold the wheel left and right and again rock the wheel, making sure the wheel bearing is properly tight. If you feel a play or notice movement it is sign the kingpin would need to be replace.

Section 4 of the Service Manual have some troubleshooting diagnostic hints that could help.

The fault most likely would be on the bearings lack of lubrication, age, etc. or the brass bushings wore out. As you know a 60 plus year car with 56K miles can be fine versus one with 35K miles, it all depends on the wear and tear and proper maintenance/lubrication performed.
J. Gomez
CLC #23082

Bobby B

Quote from: carguyblack on December 03, 2017, 03:16:09 PM
On the one 1956 I now have, I've not done the king pins as it wasn't suggested.

That's because no one wants to do that kind of work any more. I took mine to an old school machine shop so they could ream the bushings accordingly. If they've done them before, they know what the proper clearance is by feel. In my opinion, having your whole front end "gone thru" and not replacing the Kingpins is foolish. The problem is, your local auto mechanic would rather do something else than your kingpins, trust me..... ::)
                                                                                                                   Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

Lexi

That sounds reasonable. Why dig in there and not do them especially while the parts are still available? I also had a machine shop perform that job to ensure the best possible fit. Even had my drag link rebuilt. Clay/Lexi

John Washburn CLC 1067 Sadly deceased.

Folks,

The other reason for this might be the king pins. Replacing them is good but you have to know what you are doing and make sure that they are neither to loose nor too tight.

To get this right one has to have the right tools including the correct hones.

On one occasion when I had the king pins replaced it seems that one side was too tight and the other too loose. Seemed to have a similar problem.

Thank goodness this is just a hobby.

The Johnny

John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Bobby B

Quote from: John Washburn CLC 1067 on December 03, 2017, 08:22:01 PM
Thank goodness this is just a hobby.

You are SO right........ ;D ;D ;D
                                         Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

James Landi

I've owned two '56 Cadillacs--- my parents old '56 became mine, and then I purchased another years later--sum total of 20 years of daily driving experience and hundreds of thousands of miles-- have had two engines rebuilt-- paint jobs, wear issues, etc.  Some of the usual suspects have been mentioned, however, I wish to place emphasis on the following:    1. Tire pressure.  Try the Cadillac recommended pressure-- ( I know, I know--- 24 psi is considered unsafe at any speed--- but try the recommended pressure for an around town drive)---

2. Bent rim(s)- easily the most overlooked issue with an old car-- and, trust me, you can re-build the entire car, but a bent front wheel will shake this model car.

3. Idler and pitman  arms--- can set up a shake if they are worn-- having the front wheels off of the ground and pushing andpulling on them at the 9:00 and 3:00 o'clock positions will reveal worn bearings in these critical components .     

4. Re pack your wheel bearing and adjust the bearing tightness.  Ancient grease is not grease--- its an abrasive   ...     James

cadman56

I've owned several 56's and rebuilt the front ends on two of them.  I take my kingpins to a truck shop that works with kingpins all the time.
I've never felt any issues like you mention.  Could be loose wheel bearings but don't tighten like a modern tapered bearing set.
Did you replace the swa bar links?
I would sure look for looseness somewhere.  Lots of good advice from all above.
Good luck.
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

Caddy Wizard

If the front end is all "jam up and jelly tight", this car should be very quiet over bumps.  The long wheel base of the 56 60S makes a good one ride very well indeed.  And quiet. 


It sounds like you have two different issues.  One, the suspension is rattly and noisy over bumps.  That could be anything (bad shocks, king pins, wheel bearings, tie rod ends, idler arm, center link, sway bar bushings, upper pins, lower pins, etc., etc.).  The other issue is equally annoying -- a squeaky dash over bumps.  Some of these cars are completely silent behind the dash, others are noisy and I have a hard time tracking them all down.  My 55 FW is making noise behind the dash now!

I know this isn't much help.  But don't give up.  If you can make yours into a quiet one, you'll be very satisfied indeed.
Art Gardner


1955 S60 Fleetwood sedan (now under resto -- has been in paint shop since June 2022!)
1955 S62 Coupe (future show car? 2/3 done)
1958 Eldo Seville (2/3 done)