- XK Powered Saloons and DHCs Forum -

Mark 2 overdrive

Bruce Hickey
*

forum user since 2008-07-02

 

I am in the process of restoring my newest acquisition - a 1964 Mark II 3.8 4 speed with overdrive. The car needs everything and is not driveable now. I started the engine successfully and it runs fine. I pulled the motor/clutch/transmission/overdrive last week to detail the engine and the engine compartment. I want to eventually check on the clutch and the overdrive while the motor is out of the car. I am going to assume that the transmission is OK. Before I unbolted the clutch from the engine I thought I'd run a test to see if the overdrive was working. I really do not want to open up that overdrive unless it is necessary. So, I put the engine in 4th gear and ( with the plugs loosened) turned the crank shaft 360 degrees and found that the tail shaft rotated 360 degrees also. Then I attached a battery to the overdrive solenoid and it clicked-in very nicely. Again in 4th gear I rotated the crank 360 degrees. I was hoping for more that a 360 degree rotation on the prop shaft. No such luck. It rotated only 360 degrees again. Can anyone tell me if my test proves that there is, in fact, a problem with the overdrive? Or does the engine have to be running and the car moving to engage the overdrive gears??



Fan of Mark 1 saloons

Mark 2 overdrive

George Camp
Jaguar Society of South Carolina *

forum user since 2002-11-24

 

Your test tells you you have no major mechanical issues and the elec. part works. Overdrives need a lot of pumped oil pressure to work. The overdrive needs the engine to be running and you need to be in 4th gear and moving. I guess you could make a rig to test it in a static mode but you will need to presurize the overdrive pistons. I always bench check the ODs with air pressure but then again they are clean and have been rebuilt! There is no way I would do all the work you are doing w/o going through that OD.

JCRC SE
JCNA VP

Mark 2 overdrive

Bruce Hickey
*

forum user since 2008-07-02

 

Good advice. Thanks George.

Fan of Mark 1 saloons