Post Number: 198
|Posted on Friday, 10 November, 2017 - 07:22: |
I have just installed a 4 speed Moss gearbox with overdrive in my Jag Mk2.
I find that the overdrive switch effects a smooth change when engaging, but a slightly abrupt change when disengaging. To satisfy my mechanical sympathy, I have been using the clutch to help engage and disengage.
Since I have never driven and overdrive vehicle before, I was wondering if it is normal to use the clutch with the overdrive, or if they were designed to work without?
Post Number: 133
|Posted on Friday, 10 November, 2017 - 07:47: |
Patrick, on my MKII overdrive went in and out by flipping the switch and letting up on the gas. Wasn't a Moss box though. I will say that when the overdrive is set up right, that was the sweetest setup I've ever had. I mounted the OD toggle switch on the gear shift, like a splitter in a large truck. OD on top two gears.
Post Number: 149
|Posted on Friday, 10 November, 2017 - 17:31: |
I once had a Volvo Amazon with OD. Yes, you can shift the OD without using the clutch, but I think it hurts the OD in the long run. At least lift your right foot while switching on/off.
I also have had a Laycock OD retrofitted to my 20/25 HP. I always use the clutch when engaging or disengaging. I hate the jerk it gives without de-clutching, and that is not befitting a R-R.
Robert Noel Reddington
Post Number: 1570
|Posted on Friday, 10 November, 2017 - 22:32: |
An overdrive such as described works like an automatic gear box and can be changed under power.
But its good practice to lift off whilst changing in and out of overdrive.
Post Number: 1609
|Posted on Friday, 10 November, 2017 - 22:43: |
Many years ago I ran a Jaguar with a four speed box I soon fitted a moss overdrive box and wired it up with the O/D working on 3rd and 4th.
had to wire up a cut out so it would not engage in reverse, it transformed the car for MPG and lower revs.
Post Number: 201
|Posted on Saturday, 11 November, 2017 - 03:52: |
Patrick, you are right. Mine was an auto, she is now a different car altogether!