[xj40] Rear Wheel Bearing Kit JLM1708

XJ40
1

A few years ago I purchased two of these kits from a
well-known UK Jag Independent parts house � the one that
sells �genuine� Jaguar spares in a green box with a �leaper�
at Jaguar list and exactly the same OEM parts (quoting the
Jag part number with a �#� suffix) in a �plain� box for a
lower price � so naturally that is the one I bought!
I never needed to use them on my �91 XJ40, so together with
various other parts now redundant to my needs I was
preparing to offer the two kits JLM1708 for sale still in
their original boxes. The kits comprise both inboard and
outboard bearings and seals and I have (or had) no reason to
believe that they are not the exact fit required for all
XJ40s from �90 on and, according to the parts catalogue, the
identical kit is also required for both X300 and X308 cars.
Out of curiosity I decided to record the OEM part numbers of
the bearings and seals for posterity and thought I would put
them on the J-L forum �Parts Interchange� list as an aid to
others who may be able to purchase locally the OEM parts or
equivalent at a better price, but I then noticed something
odd with the seals, both of which are manufactured by �NAK�
(who I am sure are well known to all of us!) and have their
dimensions embossed on the seals.

The inboard seal is metric � 60mm i/d, 80mm o/d, 7.5mm wide
The outboard seal is Imperial - 2.25� i/d, 3.0� o/d, 0.375�
wide.

Does anyone have any XJ40 rear wheel bearing seals which
they can measure to compare with the above dimensions? I
find it difficult to believe that Jaguar would machine the
inboard bits of the hub Metric and revert to inches for the
outboard bits � or would they?

The bearings in the kit BTW are:-
Inboard �KOYO� Japan - LM503310 outer/LM503349 inner
Outboard �NTN� USA - LM501310 outer/LM501349 inner–
Bryan N, now Jag-less, but fun while it lasted.
Cambridgeshire, United Kingdom
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2

In reply to a message from Bryan N sent Fri 23 May 2014:

I, too, bought a pair of rear wheel bearing kits more than a
few years ago, figuring with three XJ40s, I’ll need them
sooner or later. Now much later, they’re still in their
nice blue SKF boxes on the parts shelf. The seal ODs appear
to be imperial dimensions, 3.006 and 3.156 inches
respectively. Neither seal measures to the even millimeter,
but the latter is really close to 80 mm. I suspect they’re
in the ‘‘true’’ system of measurement. (The world will
finally become metric when you can go into a parts store,
ask the clerk for a set of sockets, and have him reply ‘‘9 or
13 millimeter drive?’’ If he asks ‘‘three-eighths or
half-inch drive’’, you know we’re not there yet.)–
The original message included these comments:

The inboard seal is metric � 60mm i/d, 80mm o/d, 7.5mm wide
The outboard seal is Imperial - 2.25� i/d, 3.0� o/d, 0.375�
wide.
Does anyone have any XJ40 rear wheel bearing seals which
they can measure to compare with the above dimensions? I
find it difficult to believe that Jaguar would machine the

–
Pete Peterson 70E(193K) XJ40s(88-270K,89-97K, 94-122K)
Severna Park, Maryland, United States
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3

In reply to a message from Jaguarpete sent Sat 24 May 2014:

Pete,

Thanks for measuring the seals.

Those dimensions are ‘‘as near as dammit’’ to the ones in my
bearing kit so I guess Jaguar did go Imperial on the
outboard seal and Metric on the inboard seal. How strange!

BTW, isn’t it a fact that all bearings have been metric
since at least the second world war? I have a vague
recollection that the US had trouble sourcing bearings for
their tanks and aircraft during that conflict because they
designed things using Imperial measurements.

I know I was ‘anti-Metric’ as a youth - something to do with
Brit patriotism I suppose - but I soon began to realise that
that form of measurement made more sense. However, I still
measure small clearances in ‘thous’! :slight_smile:

I remember selling some aircaft to one of our Commonwealth
cousins whose military then decided to ‘go Metric’ for all
of their spares requirements. As a consequence, all the
consumable ‘raw material’ stuff we supplied in feet and
inches or pints and gallons couldn’t be processed by their
computer supply system which caused the whole operation to
grind to a halt.
We had to overcome that problem by giving each item of ‘raw
material’ a part number which also defined its dimensions or
volume and sell that part number in units of ‘1ea’.

Now of course the UK is fully metric - from pounds,
shillings and pence to linear measurement or volume but we
still measure our car’s fuel consumption in miles per
gallon!!! :-)–
The original message included these comments:

sooner or later. Now much later, they’re still in their
nice blue SKF boxes on the parts shelf. The seal ODs appear
to be imperial dimensions, 3.006 and 3.156 inches
respectively. Neither seal measures to the even millimeter,
but the latter is really close to 80 mm. I suspect they’re
in the ‘‘true’’ system of measurement. (The world will
finally become metric when you can go into a parts store,
ask the clerk for a set of sockets, and have him reply ‘‘9 or
13 millimeter drive?’’ If he asks ‘‘three-eighths or
half-inch drive’’, you know we’re not there yet.)

–
Bryan N, now Jag-less, but fun while it lasted.
Cambridgeshire, United Kingdom
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4

In reply to a message from Bryan N sent Sun 25 May 2014:

 I think the bearing/seal industry ''went Metric'' in the

middle 80s, and it started with the Maritime Industry.
That’s about the time frame Canada ‘‘went Metric’’, too.
I have an International Bearing Interchange &
International Seal Interchange cross-reference manuals
published in 1979 that lists inches first and millimeters
second, with very few metric dimensions in full units. The
manuals come in handy when working on my E and the mid-70s
XJ6Ls, but not so much with the XJ40s. I don’t know if one
can subscribe to an on-line service that’s comparable, and
I’m too cheap to buy an up-dated manual. Ah, well.–
The original message included these comments:

BTW, isn’t it a fact that all bearings have been metric
since at least the second world war? I have a vague
recollection that the US had trouble sourcing bearings for
their tanks and aircraft during that conflict because they
designed things using Imperial measurements.

–
Pete Peterson 70E(193K) XJ40s(88-270K,89-97K, 94-122K)
Severna Park, Maryland, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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