Engaging 4wd and diff locks??

[kombi1976]

My wife works for a fellow who used to own Series II's and IIa's and he said when you push the plunger with the yellow knob it's a diff lock.
But by all the labelling in our IIa it says nothing about diff locks and that it engages 4wd and I gather the that means the centre differential/transfer case.
Does the plunger just engage 4wd?
Do IIa's have any type of diff lock?
Or does my wife's boss have his wires crossed?

[Phoenix]

wires crossed.

Pushing the yellow lever down engages 4wd wit ha 50/50 drive split.

the later defender and disco have 4wd, but with an open center diff so that front / rear drive can be split so as not to cause wind up. they had a center diff loch which locked it 50/50 like the series landies.

[kombi1976]

I thought so.
As much as I'd like to have diff locks the drive split alone saves you have have the situation where one wheel is spinning like mad and the other 3 are not moving at all.
Instead 2 wheels are spinning like mad and the other 2 aren't moving! :D
Mind the latter situation is far less likely than the former.

[JDNSW]

Wires crossed. Series 2/2a do not have a centre differential and do not have diff locks (unless fitted aftermarket, possible, but rare).

The yellow knob engages four wheel drive by locking the front propeller shaft to the rear propeller shaft with a dog clutch in the transfer case. It can be engaged at any time except when free wheel hubs, if fitted, are not engaged and the vehicle is moving. Also not recommended when a rear wheel is spinning at any speed.

Selecting low range also engages four wheel drive, regardless of whether the yellow knob is down or not. Disengaging low range also disengages four wheel drive.

A possible source of confusion is that early Series 1 Landrovers had full time four wheel drive, with the front drive being via a free wheel unit in the transfer case. For use in reverse, this was locked using a ring pull on the floor, which was later replaced by the familiar yellow knob, which remained when the free wheel full time four wheel drive was replaced by the selectable four wheel drive, but now became a four wheel drive selector rather than a free wheel lock.

John

[Lotz-A-Landies]

Wires crossed. Series 2/2a do not have a centre differential and do not have diff locks (unless fitted aftermarket, possible, but rare)....

...A possible source of confusion is that early Series 1 Landrovers had full time four wheel drive, with the front drive being via a free wheel unit in the transfer case. For use in reverse, this was locked using a ring pull on the floor, which was later replaced by the familiar yellow knob, which remained when the free wheel full time four wheel drive was replaced by the selectable four wheel drive, but now became a four wheel drive selector rather than a free wheel lock.

John
John's correct.

The 1950 vehicles from after almost four thousand and first four thousand 1951 80" Land Rovers had both a yellow button and a "freewheel" lock which could be confused with a diff lock.

Pretty much the only other Land Rovers that had any sort of diff lock button are those with the LT95 transmissions.

Diana

Addit: The 1950-1951 as mentioned above, had both a yellow knob and also a red knob (they looked the same as the later ones, may not be famous and they weren't selectable in 2WD ) the use of the yellow knob was only to lock the freewheel unit in reverse.

[UncleHo]

G'day Kombi1976 :)

The Series Landrover post 1951 had selectable 4 wheel drive, the famous Red and Yellow knobs :)
To select 4 Wheel Drive:


4 wheel drive High Ratio, depress the Yellow knob, this gives you FWD at the normal ratio. To return to 2 wheel drive, move RED knob lever rearwards (the yellow Knob should spring up) and return to forward position.

4 wheel drive Low Ratio, move RED knob rearwards, move forward to select 2WD High Ratio.

Both of these actions should only be carried out AFTER FREEWHEEL HUBS ARE ENGAGED (If Freewheel Hubs Fitted)

Locking Differentials were an available aftermarket item, for the rear axle only.

No Series Vehicle has a centre locking differential.

Permanent 4WD was first introduced with the Range Rover in 1970, and into the Landrover 90/110/Defender range in 1983 with the introduction of the coil sprung models.

Hope that is of help.

cheers