[xk] XK120 upper A-arm interchange-ability

A friend needs a pair of XK120 upper A-arms. I’m going to place
a ‘‘Wanted’’ ad in the free advert section, but wondered if these
parts are unique to the XK120. Are XK140 upper A-arms identical?
How about a Mark VII? Just trying to cast a wide net if possible.

Thanks in advance.

Dave S.–
1957 XK140MC OTS, 1964 E-type OTS, 1973 Maserati Bora 4.9L
Orange/CA, United States
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In reply to a message from Dave Shaw sent Thu 10 May 2007:

Dave,

The XK140 Spare Parts Manual might provide an answer, I would look
it up except that I so not have the manual for an XK140.

My understanding is that if the XK140 part has the same part number
with a suffix, they are backwards compatible.

Karl–
karl
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In reply to a message from Dave Shaw sent Thu 10 May 2007:

Dave,

XK 120/140/150 upper and lower control arms interchange. Some of
the lower control arms have an extra hole, the purpose for which I
have never been able to determine, maybe a shipping tie-down
point?. I can say that in general, the MK series suspension parts
do not interchange. MK-V parts might come closest to XK, as the XK
chassis was mostly made up of reworked MK-V stampings.

Does he need one side or both? No doubt I have a set in the hoard.–
The original message included these comments:

parts are unique to the XK120. Are XK140 upper A-arms identical?
How about a Mark VII? Just trying to cast a wide net if possible.
Dave S.


Mike Spoelker 672027
Louisville, KY, United States
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In reply to a message from Dave Shaw sent Thu 10 May 2007:

When you place the ad, be sure to state the year, or better yet the
car number. In the parts book, the early and late 120’s have
different numbers for the upper A arms as a unit. I don’t know if
they’re interchangable. On a MK7, most of the lower arm stuff is
the same as a 120 and there are some bits on the upper arms that
are the same as the 120.

Phil.–
PhilW
Virginville, Pa., United States
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In reply to a message from MikeSpoelker sent Thu 10 May 2007:

The extra hole is for the shock mount on Mark VII and XK140,
different than for 120 and Mark V, so it amounts to an
unused hole where that arm was used on late 120. The
steering angle is different on Mark VII saloons so the arms
may be lightly different lengths than on XKs. You may need
some measurements in order to correctly identify orphan used
parts.–
The original message included these comments:

the lower control arms have an extra hole, the purpose for which I
have never been able to determine, maybe a shipping tie-down


XK120 FHC, Mark V saloon, XJ12L Series II
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In reply to a message from Rob Reilly sent Thu 10 May 2007:

Thanks for the information thus far. I’m asking for photos and
measurements. This is for a homebuilt vintage race car from the
50’s that used Jag front-end parts.–
1957 XK140MC OTS, 1964 E-type OTS, 1973 Maserati Bora 4.9L
Orange/CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Dave Shaw sent Fri 11 May 2007:

Sorry I was in a hurry and said it wrong; the hole is for the anti-
roll bar link mount on Mark VII & 140.

Going back to the original question which was upper wishbone
levers, here are your choices.
C3000 front & C3001 rear, used on all Mark V and all Mark VII
C3796 front & C3797 rear, used on early 120
C4739 front & C4733 rear, used on late 120 and all 140

Someone else perhaps can supply info on 150, Mark 1&2, 8&9. A
homebuilt racer could have been made out of any of these.

The top supporting shaft was C3002 on all Mark V, VII, and 120, but
my incomplete info on 140 says it used C8123, no info on what the
difference would be.

Upper ball joint assy was C3030 on Mark V and 120, superceded by
C4498 on 120 and early Mark VII, then replaced by C7378 on late
Mark VII and 140.

The difference in the levers has to be either center to center
distance ball joint to supporting shaft, or front to back on the
supporting shaft, or both.–
XK120 FHC, Mark V saloon, XJ12L Series II
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I am trying to put together set of front suspension for an XK120 660851
I notice that
upper wishbone front C3796 is only for cars up to 660125 ie very early
then C4739 is for all XK120’s 660125 onwards and same part for XK140 and probably therefore 150
so what is the difference between C3796 and C4739?
Then
upper wishbone rear C3797 is only for cars up to 660979 ie up to early1952
then C4733 is for all XK120’s 660979 onwards and same part for XK140 and probably therefore 150

Upper wishbone lever shaft XK120 part number C3002 and XK140 C8123 what is the difference?

lower rear wishbone lever LH side C3005 superseded to C4186 and RH side C3017 superceded to C4187 once again what is the difference but being superceded at least either can be used

Any help with this greatly appreciated
terry

Did the camber spec change? Did the early cars have more positive camber? Just a guess.

I believe this is something to do with it but would like to see what the physical difference is.
It seems funny they can alter only one upper lever leaving the other the same for 2 years before changing!

Correct - The top A-arm of the MK VII and the XK120/140 are different.
In the photo top one is XK120 the middle is C-type and the bottom is MK VII. Jaguar used the top A-arms and upright off the MK VII for the C-type. I think chassis angle on a MK VII and a XK120 are not the same, hence the difference.

March '53 120 OTS.

I just today cleaned mine for paint. They have different numbers cast into them for front and rear, 40-224 & 40-225. I assume these would be late production.

Ahhh ha. Now I remember. Rereading this thread from 2007, I realize why I no longer have a spare set of upper control arms. I donated them to the vintage race car mentioned in the beginning of the thread.

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Nevermind, the OP is from 2007. I’ll bet he’s found them by now.