How about this one! `65 FHC.
New owner has trouble selecting reverse when the drivetrain
is at working temp. Presented to a Jaguar “specialist” in Paris their
analysis was clutch/carbon release. That the forward gears selected
without problem did not seem to register. Estimate to remove the
engine/gearbox to ascertain the fault, 10,000 Euros !!
New owner not to pleased, having traveled minimal miles.
The enterprise storing/caring for the “E”, knowing that I had worked
on the car for the previous owner, contacted me with the attitude that it was my responsibility to fix the fault. My response was, to the effect, that my services were not sold with the car.
But, being the reasonable bloke I am, Ahem ! and, more to the point, intrigued as to the fault, I agreed to inspect.
Two possibilities.
1 The spring & plunger that acts on the annular grooves at the rear of
the reverse selector shaft
2 The interlock system (pin and two ball bearings) that acts on the annular grooves at the front of the three selector shafts
Removed the center console/radio etc and detached the gearbox
top cover.
Checked the operating lever and reverse cog movement, no problem.
The top cover was placed in a vice, gripped on the left hand side in a
vertical position. With my left hand moving the stick and my righthand
holding the selector forks in the neutral position, so the interlock system was not activated, I tried to initiate the fault. After several attempts the fault happens,
I,try again several times then again the fault, the fault being
locking of the gearstick when selecting reverse. At the second manifestation I noticed that my right hand was applying downward
pressure, ie towards the left of the gearbox, on the 1 & 2 selector fork.
Aha! rotational movement on the 1 & 2 selector shaft is having effect
on the interlock system, a flat on one of the ball bearings or a burr on one of the annular grooves perhaps. So I dismantle the whole shebang,
Nothing, everything OK. Then the Centime dropped!
The rotation on the 1 & 2 selector shaft was allowing the flat section
at the rear (photo B) to contact the adjacent section on the reverse shaft, ( photo A ). When trying to select reverse the friction was sufficient to move the 1 & 2 shaft enough to trigger the interlock system, blocking both reverse and 1 & 2 selector shafts. There is
enough play in the selector hub to allow this.
Placing the selector fork in the selector hub groove, revealed excess
“swing” side to side, this was reduced by placing the fork in a vic
and squeezing the tips together to achieve a satisfactory clearance.
The forks , of course, controlling rotation of the 1 & 2 and 3 & 4 selector shafts.
Assemble top cover - install - road test - the occasional clunk when
selecting reverse, as normal, otherwise seems to be OK.
If the fault repeats then I will delete this post, then you will know the
above is, a load of my surname.
Re a Borg-Warner/ Tremec 5 speeder J C does it need one.
Reason for the fault when the drivetrain was at working temp, is that the friction was insufficient to overcome the weight / viscosity of the
cold oil.
Given the amount of all-syncro boxes out there, is this one singular
with this problem?
Peter B.
