Thanks to some help I got here, I replaced the infamous throttle
shaft bush on my 68 2+2. For the benefit of those who have yet to
do this on a 4.2, here is the procedure which I think is the
minimum effort for an ‘‘engine in car’’ replacement. My car is an
automatic, but the procedure is identical.
First, remove the air filter trumpets. I already had the air filter
drum off the car for some cleanup work. Underneath the carb closest
to the fire wall is a pin that connects the rear and forward halves
of the throttle actuation shaft. It is tough to get to but a 3/8
wrench will fit between the two ‘‘paddles’’ that connect front and
back halves together and a 5/16’’ ring can then be used to remove
the small nyloc nut. At this stage, the rear half of the throttle
shaft cannot be removed.
Disconnect the throttle linkage at the connection to the pivot on a
bar across the windshield wiper motor and then remove the two 7/16
bolts to remove this bar. At this point the linkage across to the
drivers side of the firewall popped off of its own accord.
The next step is to use a 7/16 socket on a short bar to remove the
four bolts attaching the windshield wiper motor which can then be
raised to get to the two 7/16 bolts attaching the bracket holding
the offending bush.
Taking care not to lose the pin attaching the two halves of the
throttle shaft, the rear half can now be removed from its socket at
the connection and withdrawn with the bracket holding the bush.
Pull the bracket and remains of the bush off the rod, push out the
remains of the old bush (mine about fell out on its own) and take
the bracket to a vice.
I sourced my bush along with a spare from XKS unlimited. It is a
tough plastic grommet with a beveled edge. I used a bit of white
grease and bevel first, was able to push the bush through the
bracket with the vice. I used a socket at the rear to focus the
pressure around the hole and to stop the bracket bending.
Reassembly is the reverse operation. The whole job took me less
than an hour and all of the slop is now out of my throttle linkage.
The hardest part was getting the wiper motor bolts back in their
holes (I put a couple of nuts inside a socket to stop the short
bolts from disappearing inside while I got them started. The only
other fiddly bit was getting the two throttle shaft halves
reconnected with the pin which is designed to maintain clearance
between the connecting paddles.
I hope this procedure helps others,
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–