1959 Series 62 Grinding-Suspect the Differential

[59tailfins]

Hello and thank you in advance. My 1959 series 62 four door just started grinding and I'm not sure what is causing it. At speeds around 50 and decelerating to around 25 there is a grinding. It will do it at the same frequency even with the car in neutral. It only does it on deceleration and gets worse when the brakes are applied. It doesn't feel like the brakes as the car continues to brake straight. 

Ring and Pinion?
Axle Bearings?
Wheel Bearings?
U-Joints?
Drive Line out of Balance?

Ideas? If it's the rear end, where do I find a ring and pinion and bearing set?

Thank you again!

Brian

[The Tassie Devil(le)]

Sounds like it could be a wheel bearing.

Raise up the car and put it on jack stands, at the diff, and then, with the transmission in neutral, turn each wheel, pull it inwards and outwards, and generally see if it is loose on one side.

While it is in the air, start the engine and with the brake on, put it in any gear and slowly release the brake, and listen for noises, especially at the hub.

Bruce.

[59tailfins]

Hi Bruce,

I did that on your recommendation and thank you. No loose wheels or symptoms at the wheels like bearings or brakes. Still have the same grinding on deceleration but not as pronounced while on the jackstands.

[The Tassie Devil(le)]

Sounds like you need grab a 6 foot length of garden hose, and get under the car, and put one end up to your ear, and the other end onto various parts of the differential, and listen for the source of the noise, whilst someone is operating the gears and brake.

You will be surprised just what noises you hear.

Bruce.

[59tailfins]

Thanks Bruce,

I will try that this weekend and let you know. I appreciate all the insight and advice.

Brian

[The Tassie Devil(le)]

Don't forget safety here.   Don't get caught up in the spinning tailshaft or wheels whilst under there.

Rotating parts are so unforgiving, and using the hose, if it does get caught up in anything, you just let it go.

Using the other listening method, "the screw driver to the ear" is too dangerous when under there.

Bruce.

[Gene Beaird]

And make sure you have someone behind the wheel when you're doing that.  They don't have to do much but pay attention, and be able to turn things off, or stop things should something unexpected happen. 

Happy noise hunting!

[76eldo]

Do it on a lift.

I would NEVER crawl under a running 59 Cadillac with that crazy X frame supported on jack stands.  Never.

Has the fluid level been checked?

Brian

[59tailfins]

I ordered rear wheel bearings, I'll start there. I'll keep you posted.

Thanks!

[The Tassie Devil(le)]

When you replace the bearings, you will need the Workshop Manual to get the correct location of the bearing in its' final location, as they aren't like normal axles where you simply press it up till it stops.   Then put on the retaining collar.

Bruce.

PS.   You do have the Workshop Manual?   If not, make sure you measure where the location of the original bearing sits on the axle.

[59tailfins]

Bruce,

I do have the manual. I will also take your advice and measure the exact location for placement.

I very much appreciate your insight and advice!

Brian

[59tailfins]

FOUND IT!! It was the farthest rear U-Joint. No bearings in it, just dust. Ive got a new one and will put it in today. Took the drive line apart and found pieces missing from the center bearing area. Any good leads on parts for that?
Thanks!

[The Tassie Devil(le)]

I hope you found it before you stripped the axles and replaced the bearings, or spent too much money on other stuff.

Bruce.