I am repairing the track rod ends on my Mark V, which are the same as most
XK120s. These are the later type C4135 and C4136 with rubber inside. I have
posted a picture.
The original did not have an outer sleeve and was not intended to be
repaired. The diameter of the hole is .907" and the repair part with the
outer sleeve is 1.003" diameter. It did not come with any instructions, but
it seems like a straightforward machining job to bore and ream the hole.
Before I begin I thought I would ask this group if anyone has done it before
now, and what tolerance to use on the hole reaming to achieve a good press
fit.
I thought I would report on what I learned about the later type C4135 and
C4136 Track Rod Ends with the rubber bushing inside. These were used on
XK120 and Mark V beginning in early 1950 to the end of production. Service
Bulletin SB61 dated Jan 1950 describes them as superceding the threaded pin
type, but comparing the chassis numbers to Porter suggests they didn’t
appear until June.
The original design was molded together and intended to be entirely
replaced, not taken apart and repaired. But clever aftermarket parts sources
have created ways to save your old forgings and just replace the pin studs
and rubber. You can press out the old pin and rubber sleeve using a bench
vise or an Arbor press, then measure the inside diameter of the hole in the
forging. An undamaged hole will be about .907" to .910" measuring with a
dial caliper.
Depending on how much worn your old bushings were, whether or not they
caused damage to the hole in the forging, you have several choices on repair
parts.
XKs Unlimited has a repair stud bushing 14-1024 that they refer to as
“Upgraded” in the sense that it is an improvement over the original design.
The outside diameter is .910" to .913" for press fitting in the forging if
it is undamaged.
If your forging is a bit damaged and needs reaming out a few mils, XKs has a
slightly oversize part 14-1019 which is .911" to .914" measured with a
micrometer.
If your forging is quite a bit damaged and must be bored out to 1.00", Moss
Motors has a part 031-820 which is 1.002" to 1.005" diameter.
XKs has another part 14-1025 which is also oversize but I did not obtain
measurements of this part.
I was not able to press in the new pins with my bench vise, so I had to use
an Arbor press.
Rob Reilly - 679187
Along the way I learned that the new pin bushings should be a light press
fit, should not require a hydraulic press to put them in. I wrecked one
doing that.
Rob Reilly - 679187