Quite a while ago I posted a note on Gumtree asking for a overdrive unit for a Series II Landrover. It’s esencially a “fifth gear” for the gearbox. Since the Landies where designed for offroad the gearbox’s ratios are rather “short.” (Think of driving your car on the highway in third…) Because of this the poor engine has to rev really high when cruising. Not good for any engine unless it’s a CBR 600 RR…

The way this overdrive works is a bit different than just a plain 5th gear. Imagine a device that can shift all the gears one position “UP.” (3rd gear becomes the same ratio as 4th.)

They way it achieves this is by changing the output ratio of the gearbox from ether 1:1 (Overdrive out) to 0.782:1 (Overdrive in). It is very similar to what the transfer box does in a 4×4 car. You either have lots of speed and moderate power (High range) or LOTS of power, but no speed. (Low range). The only difference with the overdrive is that it has a set of synchro gears. This makes it possible to engage it while driving. My Landy now went from 10 Gears, 8 forward (4 high range, 4 low range) and 2 reverse, to 20 gears. 16 forward and 4 reverse.

The Overdrive unit is an after market part originally made by Fairey, later bought out by Superwinch. They went out of production a few years ago so they are VERY hard to track down. Since they make such a difference on long distance cruising the guys that have them won’t get rid of them. The ones that are available are usually trashed or incomplete.

Monday last week I got an email from one of the guys at LR service center saying that there was a good condition Series III gearbox with a working overdrive attached to it. This meant it it was in working condition AND complete. I took the afternoon off and went to have a look. I turned the input shaft with my hand and the whole box seemed happy, turned easily and very little play on anything. I had to stop myself from ripping the unit out there and then. We arranged for the workshop guys to strip it off and I collected it the next day. It’s very simple to fit. Here is the superwinch overdrive manual. It took me 3 hours to fit, including a test drive…

I love my big Mechano set…

For those who wonder why I’m so quite:

I’ve been in Margate building LED screen for the Loerie awards. I know it’s really geeky, but we worked out in total there was 1.7Million LED’s…

Then I missioned with a screen install at Monte Casino. It is in the courtyard where they alway have Boktown when the Springboks are playing rugby. They have this awesome musical fountain here. Pretty cool.

Now I’m installing the last phase of our VoIP system in the Johannesburg branch, then off to Bloemfontein for the National Rally.

Have fun.

L