Thread: rubber donut advice

Originally Posted by pistolpete

1. when I was in the dunes on weekend I played in 2wd

Unless you have converted your car - I bit hard to do as the disco is constant 4wd.

Most likely either faulty donut or faulty installation - even if well used offroad they should last at least 50,000km.

Garry

doesn't d1 rear have more power than the front wheels when the 4h or 4l is not engaged...

i guess you mean you didn't put the centre diff lock in, as the car is constant four wheel drive,
it doesn't matter,
the car was designed with the donut coupling and that sort of drive train coupling has been around for many years,
i had a 450 mercedes with one, and have seen many high performance racing cars with these things.

i have a disco still running one and it is nearly done now, but it is 17 years old now,
how old?
didn't think it was that old!
290 kms but it is still doing it's job.

if you put a new one in and it's buggered now after a short time, i'd be looking at what the installation was like, tailshaft balance, the centre bush condition and what you may have driven over.

in another car, v8 disco,

i got stuck once on a log crossing and with guidance managed to get off the log,
problem was that i was using the donut to slide the car along the log,
exit one donut, but it got me home.

many critics on here deride the coupling, but if you don't drive sideways on logs, it is a good thing, i actually think i should never have changed the other car to a rear uni.

nope its an unbiased drive system, in any range with the TC unlocked it will send all of the torque to the wheel that can use it least.

With the TC locked it will send it 50/50 (or 100/100 depending on your understanding of driveline theory) to the front and rear crownwheels which will then decide which wheel can make least use of the available torque and send it that way.


Its kind of like tax cuts really. Those who dont need them get them and those that do dont.

There isn't much to get wrong with installing the donut - if you can post a pic of the destroyed one, it may help in figuring out what happened.

Pictures, it's still in place, getting changed today

I've been told in the past that there are 2 sources of these couplings. The genuine GKN one, and dodgy aftermarket ones.

I've also noticed myself when fitting one that there are 3 thick parts separated by three thin areas. Does it make any difference whether the thick bit is under compression or tension under normal forward drive torque? I cant see anything in the RAVE manual that says to put them one way or the other.

BTW - your one is stuffed

Steve

Not even 5000kms of travel