When is Four Wheel Drive engaged?

[DiscoDave]

My Series I has all the 'normal' gear levers for a series Landy (without PTO or overdrive) - black, yellow and red. In a Series III, as I understand it, low ratio is always 4WD but in high ratio 4WD only operates if you press the yellow lever. However reading through the operating manual for 48-51 Land Rovers it talks about engaging the "Front Wheel Drive Lock" (the yellow lever) which can only be engaged when in LOW ratio. This locks the "overrun freewheel unit". In high ratio "when the engine is coasting with the vehicle travelling forward drive is to the rear wheels only".

This sounds like a different system entirely to the Series III or have I got it wrong? When does my Series I have 4WD engaged?

[101RRS]

Are you talking about the very early series 1 with constant 4wd via the flywheel thingy or your 86. Your 86 will operate the same as any other series - push down to engage 4wd, pull back the lever to engage low range etc

I assume for the early flywheel ones it as you read in the handbook

Garry

[DiscoDave]

So there was a redesign of the 4WD system between '51 and '54?

[101RRS]

I believe so - sometime around 50/51 but I am not sure - others more knowledgeable than I will no doubt give the right answers.

Garry

[JDNSW]

The first Landrovers were constant four wheel drive, with the front axle (equipped with Tracta CV joints) driven via a free wheel unit (same as was used on some Rover cars). Since this would mean that there would be no drive on the front axle in reverse, the free wheel unit could be locked by a pull ring on the floor near the High-low lever.

This was replaced fairly early by the familiar yellow knob to operate the lock, disengaged by engaging and disengaging low. (can't lay my hand on a date)

The free wheel and the CV joints were replaced about 1951 by the familiar part time four wheel drive system that remained unchanged except for details until the early 110s.

John

[DiscoDave]

Thanks to both of you for clearing that up for me.

[UncleHo]

G'day DiscoDave

The first of the Series 1 80" inch vehicles had the "Ring Pull" gearbox transfer units, that was in use by Rover from about1932 in various forms, the 1951 models (late50 onwards) were the first to use the Selectable Four Wheel Drive system,(although the records suggest that the last 1950 models had these transmissions fitted) and the larger 7"inch Headlights, the parking lights (side lights) were moved to the Guards(wings) in the Spring of 51.

cheers

[Roverray]

Just for the record my 1950 has the tractor headlights side lights on F/wall but the later T/case ---yellow knob!

[JDNSW]

Just for the record my 1950 has the tractor headlights side lights on F/wall but the later T/case ---yellow knob!

Some at least of the free wheel front drive systems used the yellow knob instead of the ring pull to lock the front drive. But since the transfer case is interchangeable, what it has now is not necessarily what it came from the factory with.

The free wheel unit is quite different in appearance (tapers forward rather than parallel is the easiest way of describing the difference) from the later transfer case extension housing, so it is easy to tell which you have by looking underneath.

John

[101RRS]

Can someone explain how this flywheel 4wd system works? I know that one of its disadvantages is that it didn't work in reverse - why? and why were the advantages over the simple diff system used in later landies.

Thanks

Garry