Jaguar XJ-S. Manual — part 99

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“Small self tappers were used to seal off the vents. I found on my XJ6 that as I pumped, no grease came out of the Jag
supplied vent next to the zerk; it must be well and truly blocked. I got plenty of grease out my new vent holes. At first
very old and stiff grease, then newer grease sitting in the centre of the cavity, then new moly grease. I also loosed off
the 5/8" shaft nuts and rotated the shaft to rotate the bearings which spreads grease and spreads the wear pattern.

“Now I know how it should be done, I guess an hour would cover the job for both wheels. You might want a spare
drill, it is not too hard to break one. That is no tragedy, it just means you have an extra hole which may or may not
penetrate the bore.”

Since lubrication is a challenge, it might help to use the most suitable grease rather than simply whatever’s on hand.
Richard Griffiths says, “EP should be fine; in my view grease for this application requires:

High viscosity base oil at operating temp.

Water resistant filler

Oxidation inhibitor additive

Corrosion inhibitor additive

“Other additives such as Moly are of no significance for this application. In my experience Moly was usually specified
for sliding applications; in this case the trick is to keep the rollers actually "rolling" under high oscillating loads while
maintaining the oil film. EP should do better here.”

REAR SWINGARM OUTER PIVOT - OIL BATH LUBRICATION: Getting grease right into the contact points
between rollers and races is an iffy proposition at best, especially the rollers that happen to be at the top. Unlike wheel
bearings or other applications, the motion of the bearings themselves cannot be expected to help move the grease
around to where it’s needed; these rollers don’t move as far as the spacing between rollers.

Richard Griffiths proposes a novel solution: “Two things we know for sure; EP additives work and channeling can
occur in "thick" greases leading to lube starvation failures. So if I had your set up with the better seals, I would
consider using a hi visc EP oil instead of grease. Highest stuff that will still pour at say -10°F.”

Obviously, having the oil seals installed on the pivot joint as described on page 395 is essential for this idea; the OEM
felt seals will simply allow oil to ooze out, and the last thing a Jaguar needs is another oil leak. The oil seals should be
installed flat side out, since they will used to hold oil in -- exactly what they were designed to do!

Also, you need to use sealant when assembling. Apply sealant to both sides of everything in the stack along the
fulcrum shaft to make sure oil can’t leak along the shaft to get out. And before the oil seal is pressed into the hub
carrier, some sealant should be applied in the recess.

Having an oil-filled assembly sealed airtight would not be good, so using a screw to plug the grease vent as described
above is not recommended. As with other containers holding oil such as the GM 400 transmission or the differential,
the ideal arrangement would be for the joint to be fitted with a breather that allows the chamber to be vented while
keeping oil in and water and dirt out. There are a couple of ideas here. One is to drill the existing grease vent hole out
to a larger size and then thread it to hold a fitting of some sort -- possibly the same fitting as the one used on the
differential. Another is to press in a small tube and connect a hose to a remote breather, similar to that used on the GM
400; such a remote breather would need to be secured to the hub carrier so it doesn’t flap around too much when the
wheel bounces over bumps in the road. Remember to make sure the breather connection doesn’t interfere with the axle
U-joint or its cover; an elbow fitting may be in order. The simplest idea is probably to simply drill the existing grease
vent hole bigger but only part way down, not all the way through, and then jam a piece of felt or a cotton ball in the
hole.

Richard Griffiths says, “One of those breather plugs with the sintered "filter" center piece would be neat also. See the
stuff from the Stewart Warner or Tedeco companies for example.”

When devising a breather, remember that you will also need to be able to put oil into this compartment. If a really
small (1/8” or so) breather is devised, you’ll probably need to make a second hole so you can add oil to one hole while

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air comes out the other. If you make the breather hole large enough, you may be able to feed a tube down through it so
you can feed oil in through the tube while air escapes around it; a capillary tube on a syringe would work well. If you
can figure out how to get the oil in via the zerk fitting, great, but otherwise you might want to remove the zerk fitting
and plug that hole with a screw. Again, the enlarged hole with felt or cotton jammed in it provides the simplest
solution: remove the felt or cotton, fill up the chamber with oil, and jam the felt or cotton back in.

When set up this way, you want the assembly full of oil; that’s the only way oil will get to the rollers at the top of each
bearing, since they don’t spin. Griffiths points out you want to keep the seal lips wet, too. So, add oil until it appears
at the breather. This will still leave some air pockets, but driving uphill or downhill will help make sure those upper
rollers get oiled every now and then. Driving over bumps may splash some oil around in there.

Tom Wilson says, “Thoughts on oil filled hubs bring back a time when Bell Helicopters figured out that the oscillating
movement of the pitch change on the rotor blades would tend to work the lube out of the needle bearings and would
allow metal to metal contact. They went to great lengths to seal the blade grip to yoke contact point, and even supplied
a clear reservoir so one could easily check the oil level in the grips. It was for the most part a failure and you will
usually only see a UH-1 with an oiled head in a museum. The point of this tirade is simply that on a worst case, that
being an oscillating load the oiled bearing was replaced by greasing. Replacing the felt wiper with a rubber lipped seal
and using a synthetic grease like Mobil (that horrible red stuff you always see being slung out of the heads of Bell
helicopters) will almost guarantee that the wheel bearings will outlast the rest of the car.”

REAR SWINGARM OUTER PIVOT - SERVICING: Do your pivot joints need attention? Probably. Patrick
MacNamara’s did: “Old bearings were completely shot. The worst were the ends closest to the front of the car. The
starboard side inner race was almost a rusted solid mass and the outer race was pitted and dented. There had been so
much movement that it had chewed and straightened one of the annular spacers. The yaw I used to experience when
letting off the gas at speed is now gone as well as a little rear end steer/swaying when changing lanes at speed. I think
these things should be disassembled and regreased as well as rotated a few degrees every few years.”

Greg Meboe had sloppy bearings. “This can be noticed as a light to medium growling vibration as you're driving on
the freeway. This occurs only during the transition as you gently press and release the throttle. This can be
misdiagnosed as a differential problem. To test, jack up one side of the car under the steel lower suspension arm, then
remove the wheel. Pry a flat-blade screwdriver between the aluminum hub carrier and the steel lower suspension arm.
Try to wiggle the carrier forward and backward, while the suspension is at ride height. Otherwise, you can look for
evidence of scraping between the carrier and the lower arm.”

If you only need to rebuild the outer pivot joint, here are some things you don’t need to do: You don’t need to drop the
rear suspension cage. You don’t need to fiddle with the shocks and springs. You don’t need to fiddle with the radius
arm. You don’t need to mess with the rear anti-sway bar, if you have one.

The fact is, working on the outer pivot is pretty easy; just slide the axle out of the hub and remove the fulcrum shaft
from the pivot, and you can work on the hub carrier on the bench while leaving the swingarm in the car. This hub
carrier removal is clearly described in Section 64.15.01of the ROM, but is not as clear in the Haynes where the section
on rebuilding the outer pivot itself follows a section on removing the entire swingarm from the car. This seems to
imply that outer pivot work requires removing the swingarm from the car first, and that would involve some serious
work. Removing the swingarm is totally unnecessary; if you’re using the Haynes, just follow steps 1, 2, 5, 6, 7, and 8
of Chapter 8, Section 4. Then you can begin taking the pivot apart according to Chapter 11, Section 22, and as soon as
the fulcrum shaft comes out you can relocate the hub carrier to the bench.

The hub carrier removal procedures call for removing the cotter pin and the castellated “Jesus nut” holding the axle in
the hub. If you just happen to have wheels that permit access to this nut, it’s easier to break it loose first while the car is
still sitting on the wheels.

The procedures also call for a special Jaguar tool JD.1D to get the axle out of the hub. A generic hub puller will do --
but you might not even need a puller at all, it might just slide out. If you can get the Jesus nut off while the wheel is
still on -- or put the wheel back on afterwards -- you can yank outward at the top of the wheel to jar it loose.

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Still sounds like too much effort? Then forget removing the hub carrier; rebuild the outer swingarm pivot right there on
the car! Patrick MacNamara says, “Very simple job to replace the fulcrum bearings without disconnecting the hub
from the splined axle. I just laid an 18" 2x4 across the lower arm fork and rested the hub carrier on its side on the 2x4
for the pounding out of the old bearing cones.”

Section 64.15.07 of the ROM and Chapter 11, Section 22 of the Haynes manual provide step-by-step procedures for
rebuilding this pivot. However, many owners have expressed confusion; in fact, apparently Jaguar was confused,
because there are different procedures described in the manuals for different cars that all use the same rear suspension
assembly. John Napoli says, “I have opened up three fulcrum assemblies on three different Jags (my XJ6, my XJ-S and
another) and each had the parts in a different sequence, none of them matching the various and sometimes ambiguous
manuals.”

The confusion is also partly because you need something more than step-by-step procedures -- you need to know what
the hell you’re doing! There are two separate shimming procedures involved. Both are described in the following
pages; once the objectives are understood, the step-by-step instructions should begin to make more sense. Figure 22
shows the assembly, assembled at the right and the individual parts to the left indicating the order of installation. The
fulcrum shaft has been omitted, since it makes the diagram clearer and you know where the fulcrum shaft goes.

Figure 22 - Rear Swingarm Outer Pivot Assembly

Section 64.15.07 of the ROM includes instructions for rebuilding the outer pivot and for rebuilding the wheel bearings,
all in the same sequence. That only causes more confusion; although both bearing assemblies are within the same hub
carrier, they are unrelated operations and should have been described separately. If you are only rebuilding the pivot
joint, you only need concern yourself with steps 1-3 and 18-31. The Haynes manual does describe them separately -- in
fact, in separate chapters, as the wheel bearings are covered in Chapter 8.

Disassembly is fairly straightforward until right after you remove the felt seal ring itself. There is a metal ring with an
L-shaped cross section (looks like an oil seal with the rubber part missing) that the felt seal ring sits in, and this ring is
pressed into the hub carrier. There doesn’t seem to be any non-destructive way to get it out; you just have to put a
screwdriver in there and pry, which will usually mangle it beyond reusability. So, if you plan to rebuild using the OEM
felt seal scheme, you probably should order four new rings C20179 in advance; Craig Sawyers says, “this is an
expensive part - the price I have is £7 (about $10) each, and there are four on the car.” Better idea: rebuild using the
oil seal scheme described below, which doesn’t require these rings.

While you have it apart, take a flat file and file a small bevel on the inside corner of the outboard ends of the swingarm
fork. Don’t make it at 45°; rather, make it nearer to parallel to the flat inside surface of the fork tine, perhaps a 10°
angle. These bevels will make it easier to get the hub carrier back into place in the fork.

The outer pivot reassembly calls for a “dummy shaft”, JD.14. John Robison suggests you use a 5/8” wooden dowel.
Cut it to exactly 6” long. Note that a 5/8” wooden dowel may not be machined all that precisely, so trial fit it through a
new bearing before you get started. If it fits snugly at all, spend a few seconds with some sandpaper on it. It needs to

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be a slip fit, so it’s easy to slide in and out of the bearing assembly. If it’s humid out, you may need to sand it some
more.

Richard Dowling had another idea: “In my collection of rubber items I had some 5/16" ID rubber fuel hose that was
near as dammit 5/8" OD. This made excellent dummy shafts, especially for the inner fulcrum shaft that needs a real
belting to get back into position. With hard dummy shafts that belting can easily propel the dummy out and drop a big
collection of seals and spacers all over the bench. The rubber dummy is much less likely to be inadvertently propelled
and thereby helps keep your blood pressure low.”

The fulcrum shafts in the author’s ’83 have a little dowel tip on one end. Purpose unknown. If installed pointing to the
rear, it may permit the use of a simpler ride height setting tool than the one shown in Figure 17 on page 357. Other
than that, the fulcrum shafts can be installed with this tip pointing forwards or rearwards, it won’t make any different to
the pivot joint itself.

REAR SWINGARM OUTER PIVOT - BEARINGS: Craig Sawyers says, “Jag supplied a couple of cut-outs on the
inside of the hub so you can get a brass drift in to knock them out. Of course, that will be buried in grease, so you have
to go by feel, but it is not a difficult job.” It helps somewhat to have a drift that’s shaped just right at the tip, so you
might consider grinding the tip a bit -- flatten one side, etc. Also, it doesn’t need to be brass unless you plan to reuse
the bearing; a steel rod will do. And make sure to switch back and forth between sides with every whack; you don’t
want to get that race cocked sideways.

Generic bearings can be used, of course. Gregory Wells says, “Inner cone and bearing is Timken 03062, outer race is
Timken 03162, for Jaguar p/n C-16029.” Duncan Williamson indicates that NSK bearings use the same numbers. Ron
Moore says “These are the same bearing and cap as those fitted to the Triumph Herald front wheel bearing outer.”
Moore is in New Zealand; if you’re in the US, it might be more useful to know that it’s also the same bearing as the
outer front wheel bearing on the Triumph Spitfire and TR6 which were actually imported to this country.

Wells, a Jaguar parts vendor, adds, “Don't assume that because these bearings can be ordered by numbers from a
bearing house that they will automatically be cheaper than from the parts peddlers like ourselves. Jag vendors will be
cheaper than bearing houses on the Jag-specific bearings a goodly percentage of the time.”

Sawyers: “Replacing is easy. Stick the hub in the oven (I waited until my dearly beloved was out) at 100°C. Put the
bearing track in the freezer. The two parts just drop together, and then tighten up as the assembly cools down. When it
is cool, give the track a knock or two with a drift just to confirm it is completely seated in the recess.”

Conversely, Patrick MacNamara -- who didn’t remove the hub carrier from the car so it couldn’t very well go in the
oven -- used a length of threaded rod with nuts and washers to pull the bearing races into place.

The author used a similar method, except using the fulcrum shaft and nuts themselves. You will need two 5/8” flat
washers with a 1-1/2” OD, and it’s nice to also have two 5/8” flat washers with a 1-3/4” OD. Use the 1-3/4” OD
washers to pull the races in until they are flush with the ends of the hub carrier, then switch to the 1-1/2” OD washers
for the rest of the way. The threads on the fulcrum shaft aren’t very long, so you have to stop a few times and add more
spacers. The old bearing inner races make fine spacers.

REAR SWINGARM OUTER PIVOT - REPLACING BEARINGS WITH BUSHINGS: Tapered roller bearings work
best when rolling continuously; the motion helps feed grease in between the contact areas, and the continuous motion
ensures a uniform wear track. But the bearings in this pivot don’t roll far enough. Hence, the wear is not uniform, but
rather in local spots on the race. And the grease can get pushed out from between the contact points, piled up between
rollers, and the contact points actually run dry. The result is a pattern of dimples on the bearing races.

Greg Meboe agrees: “As a mechanical engineer, I must say that the choice to use tapered roller bearings in the hub
pivot area is poor, really poor. A roller bearing is designed to roll continuously, not sit in a static position. This pivot
has a high amount of stress on it during acceleration, braking and cornering, yet never turns more than one or two
degrees total! As a result the race become brinnelled, indented by the rollers which press but don't turn.” Note: the
roller bearings in this location are not only subject to brinnelling (impact damage), but also “false brinnelling”, which is