I removed the IRS had it overhauled and reinstalled a few
years ago. There were shims on the inside of the rubber
mounts which were replaced when reassembled. I am
considering renewing the mounts this fall and am inquiring
about the shims. Do I replace the existing shims with new
mounts or what is the criteria for installing shims.
Cannot find any information.
Thanks–
pete1940
Richmond, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from pete1940 sent Fri 19 Aug 2016:
Essentially one shim goes on each side of the chassis rail. I
don’t think the shims are intended for wheel alignment.–
Andrew B. '67 S1 & S1.5 FHCs,'64 S1 OTS www.projectetype.com
Adelaide, Australia
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from abowie sent Fri 19 Aug 2016:
I was under the impression that the shims were used to
aligned the rear end during assembly and are specific to
each car.–
Mark 69 E SII OTS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Mark,
The opening in the mounts is just about exactly 2 shims wider then the mounting point. Like many here I’ve pulled my share of diffs and usually found one shim on each side of the mount.
Bob
889076
Plymouth, Mi.On Aug 19, 2016, at 8:52 PM, Boffi marcoboffi@comcast.net wrote:
In reply to a message from abowie sent Fri 19 Aug 2016:
I was under the impression that the shims were used to
aligned the rear end during assembly and are specific to
each car.
In reply to a message from Bob Test sent Fri 19 Aug 2016:
I believe that is exactly how my shims are placed.
One more thing learned…
Thanks Bob.–
Mark 69 E SII OTS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
When such questions come up, you can often find a clue by looking
at the Jaguar Parts List or Service Manual. The name used for a
part can be a good clue to it’s purpose. In the parts list, these
parts are referred to as:
C.17228 Packing Piece, on Bolts, at each side of Body Unde-rframe
Members - 8 off
So, it’s pretty clear that Jaguar intended one to be placed on
each side of all 4 mounts. Seems clear to me…
Humm. Wonder why they wouldn’t just make them to fit in the first place
if you your cage was a little skewed you could acts Jul align it to a degree be alternating these shims on either side.
=============
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
When such questions come up, you can often find a clue by looking
at the Jaguar Parts List or Service Manual. The name used for a
part can be a good clue to it’s purpose. In the parts list, these
parts are referred to as:
C.17228 Packing Piece, on Bolts, at each side of Body Unde-rframe
Members - 8 off
So, it’s pretty clear that Jaguar intended one to be placed on
each side of all 4 mounts. Seems clear to me…
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
In theory you could make small adjustments if your chassis
legs were welded in wrong during restoration - but you’d
need to do this correct to compensate for something not done
correctly.
IF you move the cage left or right to crutch fenders not
welded on right (to make the tire to wheel well lip even)
you may introduce a slight dog track, but if the driveshaft
flanges are parallel, this is technically not the end of the
world. You have roughly 1/8 th inch to work with.
If you need to skew the cage you may have some real problems
and the driveshaft flanges will possibly now be out. Some
truck and hot rod guys say you need one half degree to work
the u-joints, but that half degree must be parallel.–
The original message included these comments:
Humm. Wonder why they wouldn’t just make them to fit in the first place
if you your cage was a little skewed you could acts Jul align it to a degree be alternating these shims on either side.
–
Larry Velk: '64 FHC,928, FZR1000, XR4ti, 325Ci
New Berlin, WI, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
Tom,
I was wondering about that too, and came to the conclusion that
as well as offering some scope for adjusting for manufacturing
tolerances (e.g. with thinner/thicker packing pieces), the main
purpose was to make it easier to install the IRS. Imagine what
‘‘fun’’ it would be installing the IRS if the mounts were a close
fit to the beams. Getting a 400lb lump to align in four places
at once as you lift it into place would be a problem for most
service shops I suspect. Instead, with the mounts being wider
than the beams, you can lift it into place, slide the bolts
through, and then fit the packing pieces, before tightening the
nuts to clamp it all together. Just a thought…
-David–
The original message included these comments:
Humm. Wonder why they wouldn’t just make them to fit in the first place
if you your cage was a little skewed you could acts Jul align it to a degree be alternating these shims on either side.
On my car, the forward mount position has one shim welded to the
inside of the beam. The new mount fits very snugly on that. This is
the same on both sides. On the rear mount position, there’s no such
shim/spacer welded in place and I don’t recall removing any loose
ones. The new mounts are a loose fit in those rear positions.
Think I’ll make some up or buy new and fit them the same as the front.On Fri, Aug 19, 2016 at 7:01 PM, abowie abowie1965@gmail.com wrote:
In reply to a message from pete1940 sent Fri 19 Aug 2016:
Essentially one shim goes on each side of the chassis rail. I
don’t think the shims are intended for wheel alignment.
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
Tom,
The part number, c.17198 is common to the S Type/420, and basically
the same as the Mark X.
I can imagine a few scenarios where the part may have been
evaluated during the early design and testing of the IRS cars, and
a decision was made to use one tooling set and part which could be
used on a range of cars. Someone may have said ‘‘If we make that gap
a bit wider it could accommodate wider chassis legs for the heavier
cars.’’ Even if someone had objected ‘‘But that would mean using
shims to make up the size difference.’’, the rest of the team would
probably just have stared in confusion at the idea that anyone
could possibly have an objection to the use of shims.
Andrew–
The original message included these comments:
Humm. Wonder why they wouldn’t just make them to fit in the first place
–
1968 3.8S
Zurich, Switzerland
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
=============
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
Tom,
I was wondering about that too, and came to the conclusion that
as well as offering some scope for adjusting for manufacturing
tolerances (e.g. with thinner/thicker packing pieces), the main
purpose was to make it easier to install the IRS. Imagine what
‘‘fun’’ it would be installing the IRS if the mounts were a close
fit to the beams. Getting a 400lb lump to align in four places
at once as you lift it into place would be a problem for most
service shops I suspect. Instead, with the mounts being wider
than the beams, you can lift it into place, slide the bolts
through, and then fit the packing pieces, before tightening the
nuts to clamp it all together. Just a thought…
-David
The original message included these comments:
Humm. Wonder why they wouldn’t just make them to fit in the first place
if you your cage was a little skewed you could acts Jul align it to a degree be alternating these shims on either side.
I agree with Andrew, especially seeing as the usuals, SNG in this
case, offer only 1 size shim and state that eight are required. This
does not suggest to me that there’s any kind of variable alignment
work needed here but that the mismatch dimension is a fixed and known
quantity and so the shim size is also fixed…all points
to “one size for all” from Jaguar during manufacture and shims will
fix any mismatches across the models.On Sat, Aug 20, 2016 at 8:17 PM, Tom Felts tomfelts@windstream.net wrote:
=============
In reply to a message from Tom Felts sent Sat 20 Aug 2016:
Tom,
I was wondering about that too, and came to the conclusion that
as well as offering some scope for adjusting for manufacturing
tolerances (e.g. with thinner/thicker packing pieces), the main
purpose was to make it easier to install the IRS. Imagine what
‘‘fun’’ it would be installing the IRS if the mounts were a close
fit to the beams. Getting a 400lb lump to align in four places
at once as you lift it into place would be a problem for most
service shops I suspect. Instead, with the mounts being wider
than the beams, you can lift it into place, slide the bolts
through, and then fit the packing pieces, before tightening the
nuts to clamp it all together. Just a thought…
-David
The original message included these comments:
Humm. Wonder why they wouldn’t just make them to fit in the first place
if you your cage was a little skewed you could acts Jul align it to a degree be alternating these shims on either side.