March 2011

INSTALLING UNIVERSAL JOINTS ON YOUR ‘49
By Art Gardner
If you start getting a “clanking” noise under your car, particularly when you step on or release the gas pedal, your universal
joints may be worn and in need of replacement. I recently installed a set of U-joints on my car‟s driveshaft. It took about 30
minutes to drive out the old ones and install the new ones. All you need to replace them is a screwdriver, a hammer, a large
socket to support the end of the driveshaft and receive the "cups" and a 17 mm impact socket (I think 11/16) to use with the
hammer to drive out the cups.
You remove the clips and drive one cup in (part at top left in the illustration below), which forces the opposite cup out. Then
grab the cup that is jutting out with a pair of pliers and twist it until it is removed. Then tap the cross piece (part at lower left)
back in to drive the other cup out the other way, then grab and remove the second cup with pair of pliers. Now just position the
new cross in the yoke (part at lower right) and tap in the new cups, being careful to make sure that the needle bearings all stay
in place. Once you have the cups tapped into position, lock them in place by installing the new C-clips (2.1440).
EXPLODED VIEW OF A TYPICAL UNIVERSAL JOINT
TECH TIP: IF YOUR REAR AXLE IS NOISY
By Jay Friedman
The first thing to do is check the gear oil level in the differential. Lack of oil can cause a noise in the differential gears. It
should be within a ½ inch of the upper hole and should be 80/90 weight oil. If oil is low, check your pinion seal as well as the
large, round gasket where the differential meets the axle housing and the outside of your rear brake backing plates for leaks. If
your pinion seal is leaking, unless you have the necessary tools and equipment it is best replaced by a professional, as the
bearing and pinion nut need to be specially dealt with. The shop manual has details. The large gasket, sold by Olson‟s
Gaskets, can be replaced without special equipment by removing the differential, though be careful as it is very heavy.
If there is a leak on the rear brake backing plates, (4.0010 in the diagram below.) ascertain whether it's brake fluid or gear oil.
If gear oil, there are oil seals on the outer ends of the axles (2.0093 in the diagram.), which when faulty will permit leaks of
gear oil into the wheel area which will then drain out a hole where the axle meets the outside of the backing plate. To replace
the seal, you must remove the axle, pull out the seal with a seal removing tool (or pry it out with the end of the axle) and drive
the new seal all the way in with a large socket wrench or similar tool. (I can lend members my home-made tool if need be.)
When you re-install the axle, spread some chassis grease on the rubber part of the seal so the axle doesn‟t scrape and damage it.
Such a leak can also be caused by a faulty gasket between the backing plate and the axle housing (4.0018). To replace this
gasket, remove the axle, unscrew the hydraulic brake line from the wheel cylinder and remove the backing plate.
Check the axle bearings by driving the car when the noise is present. One way to tell if an axle bearing is causing the noise is
to turn the car sharply in one direction and then the other. If the noise varies in intensity while doing this, it could signify a bad
bearing. To replace an axle bearing (22.0240), you must remove the axle. It is not essential to remove and replace the seal at
the same time, but it would be prudent to do so. The bearing must be pressed on the axle by a machine shop, being careful not
to score the surface on the end of the axle that the seal rides on. (Now that cars are mostly front wheel drive, there are fewer
auto machine shops that press on rear axle bearings.) These bearings and seals are sold by Olcar Bearings, Southern Pines NC
for a reasonable cost, though you may find them at a modern auto parts supplier as they are standard for many cars. .