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Jaguar XJ-S. Manual - part 25

Some argue that having a master link is a real problem, as though they are weak or some such. They are not weak; they
are typically stronger than the other links. They do, however, have some history in motorcycle applications of failing
catastrophically. This isn’t because they’re weak but rather because they can be taken apart; whatever clip or cotter pin
is used to hold them together can come out and cause the master link to fall out. This is especially a concern on a
motorcycle where running over some brush might knock the clip loose on a master link. There’s also the concern that
some motorcycle mechanics are meatheads who can’t figure out how to get the clip on the master link securely.

Of course, there is little chance of foreign interference in a master link inside the Jaguar V12 block. If you are offered a
chain with master link, simply look over the retention scheme. If it looks like something you could get together and
trust that it won’t fall apart at 6500 rpm, go with it; don’t worry that it’s somehow not as strong as the other links. If it
looks like something that might come apart, consider having the chain permanently made into a loop at the shop rather
than risk fiddling with the master link.

Some master links are held together with a clip that slides over one pin and snaps onto the other. There’s no known
history of these coming loose, but the fact that they involve a groove around the end of both pins suggests a possible
improvement: you can simply discard the single clip and install two tiny E-ring clips instead, one on each pin. There’s
little chance that an E-ring clip would come off in use, and both of them would have to come off before the chain
breaks. They are prone to getting dropped during installation, though, so be sure to tie a thread to each one before
installing.

Of course, you need to find the correct size chain. Tony Bryant says, “One possible gotcha is the old Brit vs US
standard thing. It appears there are two standards for 3/8" duplex chain: BS288/ISO606/DIN8187 and
ANSIB29.1/ISO606a. The differences are subtle but probably serious. From the Reynolds chain book, the differences
are (BS vs ANSI):

Roller width (i.e. between the inside plates) 5.72mm vs 4.68mm

Roller dia 6.35mm vs 5.08mm

Plate height 8.26mm vs 8.66mm

Plate outer width 1.04mm vs 1.3mm

Pin dia 3.28mm vs 3.59mm

Pin length 23.8mm vs 25.65mm

Breaking force 18500N vs 20000N

“So make sure you get the right chain, or I'm guessing very bad things™ will happen.”

It’s possible to replace the chain by removing only the right side cam cover and without bothering the timing cover at
all, but this requires the use of a master link -- if contemplating, make sure the chain you purchase isn’t already formed
into a loop. Retract the tensioner, then break the old chain on the top of the cam sprocket (grind the end off two pins
and slide a link out) and connect the new chain to the end of the old one with the master link. Have someone turn the
crankshaft slowly while you feed the new chain in and the old chain out, being sure to keep the cam sprocket engaged
at all times. When the master link comes around again, disconnect the old chain and connect the new chain back to
itself.

It is highly recommended that the latch on the timing chain tensioner be rocked after, or preferably during, this timing
chain replacement on the chance that the new chain is significantly shorter than the old worn one was and therefore the
tensioner needs to back up a bit to allow it to sit properly.

OIL PUMP CLEARANCES: If you happen to have the Haynes manual, the clearances specified for the oil pump don’t
seem to make sense. So, I will include the values from the ©1975 ROM here:

Driven gear to housing:

< 0.005” (0,127mm)

Drive gear to crescent:

< 0.006” (0,152mm)

End float - both gears:

< 0.005” (0,127mm)

Note that, according to the ROM, all measurements are taken with the pump removed from the engine. Since the
crankshaft is therefore not holding the drive gear in position, it is free to move as far away from the crescent as the
tightness of the gear teeth will permit. It appears a rare case that it will meet the 0.006” limit; 0.040” is more likely!
Despite the clarity of their measurement procedure, it is probable that the specified values represent clearances in place,
with the crank holding the drive gear in its correct location.

Mike Morrin: “I cannot believe the figures in the Jaguar manual. The endfloat on the gears in my pump was over
0.020”. At the time I was rather alarmed, as the engine had by all accounts only done 55,000 miles. I carefully
inspected the old parts for wear, and found that the factory machining marks were still visible on the gears, and the
wear on the pump housing was negligible. This pump must have left the factory with clearances way beyond the
published limits. So I put the old pump back and crossed my fingers. The oil pressure seems OK (when measured with
an accurate gauge).

Of course, if endfloat is the only problem, some of us have been known to skim a little metal off the mating surface of
the housing to bring it back down. With a little care, it’s even possible to perform this fix on aluminum housings by
laying a piece of sandpaper on a plate of glass and sliding the housing back and forth on it.

OIL PUMP REPLACEMENT: According to Thomas E. Alberts, the 1992 upgrade of the V12 included a new design
oil pump -- and that the old design oil pumps are no longer available. “The original part number is C38453 or C40177.
That part was officially superseded by EBC3163 which is the pump for 1992 on. EBC3163 is supposed to fit the older
engines but some pieces are required to adapt it. This pump is at least twice as expensive as the earlier version, and the
adapter (they call it a pump collar) is $45 plus some additional bolts are required.”

Engine Work -- Bottom

Note: If you only need to replace piston rings and/or liners, you might not need to do bottom end work on the Jag V12.
See the ideas on page 78.

OIL PAN REMOVAL: The crankcase bottom is actually two pieces, a pan and a sandwich plate. The pan, which
exists only at the rear of the engine, comes off easily enough. However, any hope that this will get you anywhere is
quickly shattered. The crankcase is fully baffled (necessary to prevent foaming, reduce heat buildup and power loss,
and insure proper oil flow to the pickup in a high RPM engine), and there is one baffle the length of the engine that
cannot be removed without removing the sandwich plate.

Contrary to the manual, the sandwich plate can be removed without pulling either the front suspension assembly or the
engine out of the car. It’s a real pain, though, so you might still consider one of those options. To remove the sandwich
plate:

Unbolt the steering rack without disconnecting hoses, steering column or tie rods. Lower the rack a
few inches and let it hang there.

Remove the fan to allow the engine to be raised without hitting the shroud.

Remove the nuts from the two main engine mounts, and use a hoist to lift the front of the engine as
far as possible.

With all this done, the sandwich plate will just barely come out rearward. Putting it back in, with new gasket in place,
will also be a lot of laughs.

While you’re in there, replace all the O-rings you can find, such as those in each end of each oil tube. If they leak they
just leak into the crankcase, but each leak reduces oil flow to the engine. Use Viton O-rings, so you won’t have to go
back in there anytime soon.

OIL PAN/SANDWICH PLATE BOLTS: Technical Service Bulletin 12-35, which introduced the upgraded gaskets
used throughout the engine, also specified new bolts for holding the sandwich plate and the oil sump to the engine. The
explanations given applied to both the sump and the cam covers, so it is probable that the same sort of generic bolt &
washer substitution described at length for installing the cam covers starting on page 59 could also be applied here --
although these bolts are a size larger, so the specific parts mentioned won’t do.

See also the notes on TSB 12-53 on page 47 regarding sealing the threads on the sandwich plate bolts with heads inside
the oil sump.

TSB 12-35 specifies a torque of 21-27 N-m (15.5-20 ft-lb) on the sandwich plate bolts and oil sump bolts. No mention
of later metric vs. early SAE bolts; hopefully, it’s a reasonable torque for either. It’s also probably a good spec whether
using their special bolts or generic substitutes.

MAIN BEARING REPLACEMENT: If you find yourself needing to replace the main bearings without removing the
crankshaft, the job can be accomplished the same way as most cars: Roll the upper bearing shell around and out. If it’s
difficult, insert a cutoff head from a nail into one of the oil passages of the crank and turn the crank to roll the bearing
around. However, when installing the new bearings, remember that the Jaguar block is aluminum. It is recommended
that the outer leading edge of the bearing shells be smoothed slightly with a file to prevent them digging into the
aluminum when installing.

REAR OIL SEAL:  If you think your rear oil seal is leaking, you might want to check again. The rope seal used up to
VIN 160010 has proven to be very reliable indeed; an informal survey of owners on the internet indicated that the rear
oil seal was often blamed for leaks, but the leaks were always later found to come from other sources.  The upper
mating surface of the rear bearing cap is one possible source, as Jaguar didn’t see fit to seal it at all -- see Figure 7
below.  The sides of that cap were sealed with “hockey sticks” on early cars, but later assembly instructions call for
injecting silicone instead; apparently the hockey sticks would dry up and harden and start leaking.  Besides these
possibilities right near the rear seal, there’s also the half moon seals (page 59), oil pressure sender (page 46), tappet
block banjo bolts (page 43), and a host of other items that may be leaking above or around the rear of the engine and
dripping down to look like a rear oil seal leak.

If your rear oil seal is leaking, please see the note on the PCV system on page 50.

REAR OIL SEAL -- UP TO VIN 160010: Up through engine number 8S.66782, the rear oil seal was a “rope seal”, a
chunk of waxy rope crammed into a groove surrounding the crank journal. This is sometimes called the “two-piece
seal” since there’s one piece of rope crammed into the journal on the block to form the upper half and another piece of
rope crammed into the bearing cap to form the lower half.

At first it seems apparent that the upper half of the rear oil seal cannot be replaced without removing the crank.
However, Dick Russ reports that there is a tool called “Sneaky-Pete”, P/N 2700 by the Lisle Company in Clarinda, IA,
that will enable the seal to be replaced without removing the crank. The tool costs only $6 or so and is available at Pep
Boys, AutoZone, etc. It consists of a length of music wire and some tiny grippers that can be used to bite into one end
of the new seal and pull it into place around the crank.

In the March/April 1995 issue of Jaguar Journal, Russ describes in detail how to replace this seal with the crank in
place; the same article is reprised in the December 1995 issue of British Car. It also can be viewed online at:

http://www.terrysjag.com/seal.html

The procedure was developed by Phil Long and not only uses the Sneaky-Pete but also uses the seal from a 1968-78
Ford 460. The reasoning is apparently that the Ford seal is longer than the Jaguar original. After using the Sneaky-Pete
to pull the new seal around the upper half of the crank, the end that has been boogered up by the grippers of the
Sneaky-Pete can be simply cut off. If a Jaguar seal is used, the gripper must be carefully removed and the seal backed
into the recess, no easy task.

Russ also suggests that the cap be trial fit and torqued down, and then removed and inspected to make sure none of the
seal is getting in between the joining faces of the cap and block and holding them apart. Any fibers or edges of the seal
interfering with the fit can then simply be cut away before fitting the cap up final.

Note that Long’s 44-step procedure was actually written for the Series III E-type, so a few of the steps need revision to
apply to the XJ-S. For example, steps 6 and 39 deal with the E-type’s oil-to-coolant oil cooler which doesn’t exist on
the XJ-S.

In the September/October 1995 issue of Jaguar Journal, John F. Quilter and John W. Yerger of Jaguar responded to
the above procedure, claiming it was not only unacceptable but would invalidate the warranty on the engine. They
insist that the only acceptable method of replacing this seal involves removing the crank so that a special Jaguar tool
may be used to “size” the seal prior to assembly. The seal is not supposed to actually touch the crank at all, but to
reside very close to it. The scroll carved into the crank then feeds inward, preventing oil from going outward. Contact
will result in “burning”, as confirmed by many who have found the white rope seals somewhat charred. Roger Bywater
seems to feel that the big problem is not burning of the seal itself, but burning of the rear main bearing; he says the
crank rubbing on the rope seal gets the metal hot enough to damage the bearing.

Note that the original Jaguar seal is a waxy white rope, while the Ford 460 seal appears to be impregnated with
graphite. Perhaps this helps avoid that burned look -- or camouflages it. There is at least one report of an owner asking
for a seal for a Ford 460 and being handed something in a rubber seal; make sure what you get is in fact a dark-colored
piece of rope. John Holmes says, “The Ford Rope seal is Part #C90Z-6701-A and contains 4 lengths of rope seal.
Each one measures in length 17cm, 11mm by 5.5 mm in cross section. It truly looks like a piece of rope that has been
flattened from a circular cross section. The surface of the pieces are dark grey, presumably with graphite ( it feels to be
such ) but the graphite does not penetrate very much beneath the surface. The rope pieces are quite flexible to the
hand.”

If you are concerned about contact between the rope seal and the crank, perhaps a minor revision to the Sneaky-Pete
installation is in order. It shouldn’t be difficult to slip a piece of thin shim stock around the crank before pulling the
new seal into place. This will not only hold the seal away from the crank a few thou and hopefully help the seal form to
that shape much the same way as the special Jaguar tool would, but it also helps protect the crank while installing the
seal. A similar piece of shim stock could be used when trial-fitting the bearing cap to “size” the lower half of the seal,
where Long’s procedure calls for the use of the special Jaguar tool.

Hey, if the engine is under warranty, let the Jaguar mechanics do it their way; it’s their nickel. However, if you’re
paying, I’ll bet you opt for the Sneaky-Pete. Jaguar’s way requires removing the crank, which means pulling the engine
and tearing it apart. Long’s way only requires removing the oil pan and sandwich plate, not easy but possible with
engine and transmission in place -- see page 96.

REAR BEARING CAP UPPER JOINT SEALING: When bolting on the rear bearing cap, think about how the sealing
of the crankcase itself is accomplished. The oil seal theoretically forms a seal around the shaft, and the injection of
silicone sealant effectively seals along the two sides of the bearing cap. However, the top surface of the cap is sealed
only by the metal-to-metal contact. It is suggested that a thin line of sealant be applied to the top of the bearing cap,
starting at the oil seal and ending at the silicone groove on each side, prior to assembly. See Figure 7. Be sure to use
some type of sealant that won’t space the cap away from the block, such as Loctite 518 or perhaps the Loctite 573 or
574 used on the tappet block (see page 70). Note that the sealing of this horizontal joint definitely calls for a different
sealant than the two vertical joints, which need a silicone-type stuff such as RTV.

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