1959 Driveshaft Center Bearing Replacement

[R S Steven]

Hi All,
I will be replacing my driveshaft center bearing & support bracket this week.  I was wondering what size crows fool I need to undo the nut holding the two half together?  I would like to have it on hand to speed the job up.
Thanks in advance.
RS Steven

[wbdeford]

I don't know, but for those who might, it would help to know the year and model

[R S Steven]

Thanks Wbdeford,
I don't know what I was thinking leaving the year off.  Its for a 1959 model 62.
Thanks

[Gabe Davis]

Hi RS Steven,

I replaced the center carrier bearing a couple of years ago as it was making a lot of noise when the car was at speed. It is pretty straight forward to remove, just unbolt the retainers between the differential and rear most U joint, remove the two bolts in the middle of the X frame holding the center carrier and slide the shaft out of the X frame toward the rear of the car.

I considered trying to do the bearing and U joints myself but getting the shaft apart looked problematic (the big nut you mention) so I ended up taking it to a driveline shop. They replaced all three U joints and the center carrier bearing. The shop said that the rubber in the carrier was in great condition and that it did not need to be replaced. When they reassembled the drive shaft they spin balanced it as you could see the new weights and arrows they used to keep everything lined up. The guy pointed out that the balancing was particularly important with the dual section shafts.

I was reading about the various trouble that people have had with these dual section shafts and vibrations. Some had vibration at take off speed, some around 25mph and others higher. Apparently there was a service bulletin issued by Cadillac at some point about adding shims under the center carrier between it and the X frame to help align the shaft properly. I could not find a clear answer as to whether these shims were added at the time of manufacture or if they were only added if a customer complained about the issue.

After reading about the shims I pulled the shaft back out and with a very long handled brush swept the inside of the X frame out removing not only quite a lot of dirt, but also two shim plates. I taped them to the bottom of the carrier (this was quite a pain to reinstall with the shims in place trying to align the two shims and carrier) and bolted the shaft back in. I remember seeing something about later cars, maybe '61-'62, having slots cut in the X frame making aligning the shims and carrier much easier.

I still have a vibration that starts at about 50mph but I don't think it's related to the drive shaft. Possibly it is sagging springs or old rubber bushings in the rear that are throwing something out of alignment. But at least the carrier bearing is quiet now.

[The Tassie Devil(le)]

When I made up my shims, I drilled a hole in each end, and bent up a piece of welding wire so that I could position the shim whilst fitting it.   No room for putting my hand in there.

I made the crows-foot spanner out of a bit of scrap steel.

Got to mark what these special tools are for for future reference.

Bruce.

[R S Steven]

Hi Gabe & Bruce,
Thanks for the info and write-up.  The pictures are a great help.
Bruce could you measure the distance between the flats on the crows foot?

Thanks
R S

[Jon S]

If the center bearing is lubricated as specified every 2,000 miles, it should last forever!

[R S Steven]

Hi Jon S,
I don't see anything in the shop manual on how to lubricate the center bearing.  Please tell me how / where to lubricate it. Thanks 
The reason I am replacing the center bearing is the support is no longer bonded together and the bearing  is moving around.

Thanks,
R. S.

[Jon S]

It requires a special attachment added to the grease gun but there is (should be) a hole the attachment fits into and to apply grease.  If your new one has the fitting, make sure you maintain grease in it. 

It's not a Zerk fitting, but rather looks like a hole the attachment fits into.

The Shop Manual makes no mention of it.  A Cadillac mechanic in Cody, Wyoming showed my dad where it was and how to grease it while on a cross country trip in 1961 and my local mechanic has the attachment for that purpose.  Why the Shop Manual makes no mention is beyond me.

You have to turn the drive shaft while the car is in the air to line up the access hole.

[R S Steven]

Thanks Jon S For the info.  I'll check the new part when it arrives for a hole for lubricating the bearing.
Thanks Again,
R. S.

[59-in-pieces]

Maybe it's a me too moment - belt and suspenders - or TMI.
Don't forget to replace the nut locking plates on the U-joint bolts - see pics.
Bend the ears up to the nuts - duh!!!
Have fun,
Steve B.

[The Tassie Devil(le)]

The distance between the flats is 1 27/32".

But, in my measuring, I also must correct the thickness of the metal as it is actually 5/8"   Not 3/8" as I initially noted.

Handling it again brought back memories of filing and grinding it to get it to its' finished size.

Looking at the depth of the letter stampings, I think I was taking out my frustrations with the hammer on each of the stamps.

Bruce.

[R S Steven]

Thanks Steve & Bruce.
Were do I get new locking tabs?

Thanks,
RS

[R S Steven]

Hi All,
Well My center bearing & Support finally arrived the other day.  I took the driveshaft out tonight and reached in the frame with a brush for cleaning a frig condenser and didn't find any spacers.  I then reached in there passed my elbow and still didn't find any spacers.  Now my frame has a depression about 1/2 inch where the bearing support mount.  Did Cadillac change the frame at some point and eliminate the spacers? Here are some pictures of the depression in the frame.

Thanks in advance for the help.
R. S. Steven

[The Tassie Devil(le)]

There are no spacers there, and any that might be there would have been placed there in an attempt to solve driveshaft issues.

From the factory, there were never any issues, as every part of the suspension was brand new, and therefore in factory alignment.

As things wear out, issues with driveshaft alignment can cause vibrations.

Bruce.

[R S Steven]

Thank's Bruce for the clarification. I'l put it back together tonight.

Thanks again.
R. S.