Poor man's limited slip diff

[brianw]

"Poor man's limited slip diff"

By no means is this technique to be used regularly, but only in an emergency.

Having just read a posting by Ste (Drift) headed “4 wheel drive FAQ" http://www.fronteraowners.co.uk/forums/viewtopic.php?f=41&t=50290, I thought I would tell of a driving technique I have used in the past.

We've probably all seen or experienced the main problem presented by a normal differential gear; that of one wheel on a good grip surface and the other wheel on the axle on a slippery one. No matter how hard or softly power is applied, the wheel on the slippery surface continues to spin and the one on the good grip might just as well be square.

The normal differential gear can be misdirected into working as if there's a good surface under both wheels and send the power to both by introducing a small amount of resistance to the spinning wheel.

The trick is to just ease the handbrake on slightly so that it just starts to bite and present that resistance and then to gently apply some low torque power (second gear or even third) and both wheels should then turn and hopefully ease you slowly out of the mire. It's helped me out of trouble once or twice in the old days when I was daft enough to get into the situation in the first place. Use low torque because all you want to do is to get the wheels rolling, not driving. Once you’re clear, drop the handbrake and drive normally, remembering to stay out of the mud next time.

This is particularly useful if you find yourself in a two wheel drive car (Mrs. Fronty Owner’s) and the car park at Sainsbury’s has been flooded with slimy mud!

Obviously, if 4WD is engaged and the front axle is on grippy ground then the rear axle should just be dragged out of trouble. Alternately you could fit a winch, but you have to get home first to do that.

This technique will only work on vehicles with rear wheel drive and the handbrake acting on the rear wheels, unlike earlier versions of the Landy Defender which uses a prop shaft handbrake.

Regards, Brian