Diff Brake

[Tonks4x4]

Hi guys I have been pondering this idea for quite some time...

As we all know standard Audi rear calipers are temperamental at the best of times so I have been thinking of making a handbrake disc that bolts between the propshaft and the nose of the rear diff.

Then a bracket mounted to the front of the diff holding a caliper just for the handbrake.

Land Rovers have had something like this for years and works very well.

And copes with all weather conditions, terrain etc.

I have had one on a dedicated off road vehicle for nearly 10 years and I have not had to lay a spanner on it.

Doing this will open up a completely new avenue for different caliper conversions for the rear as they will not need any type of handbrake.

What do you think???
Is it worth my time and effort to get something made?

[rj scotty]

Id be very interested

[bigcooler]

sounds like a brilliant idea

[Donnie]

I guess it would be an independant mechanical brake for mot purposes.
Wonder if there is a good spot for the caliper to go, is there sufficient clearance for a disk without it hanging down and getting nailed by rocks/ the road (over jumps)

[Ryss]

Hmm.. good idea. Could machine the hub off a normal disc and bolt it to a flat plate that is machine to fit in the diff like a cv and on the other side the plate can be machined to accept the CV. Propshaft may then still have enough play / travel.

How would the centre diff handle a hand brake turn?. Just do not do one !

However back brakes do not add much to effective braking in my mind. On my track car with standard brakes, it is so light on the ground under full braking, one has to balance the car on the front wheels, or the back will swing out either left or right.

[Tonks4x4]

You would dump the clutch at the same time as the handbrake turn as you would in a Quattro as a rule anyway.

[Donnie]

If you stopped the crownwheel would the inside wheel try to turn backwards as the weight went over to the outer side?

[Tonks4x4]

I would not have thought so.
To be honest a handbrake is not primarily for turning your car in the road but to be able to hold it on a hill.

Any other thoughts????

[rj scotty]

Only one really...............clerance

[driftin jo]

If you were parked with one rear wheel on something slippery like ice
you could run the risk of it not holding as the wheel on the ice could just turn
backwards and the other wheel turn forwards.
Of course if you also put it in gear you are would be applying the braking force to
the front wheels also, so much less chance of this being a problem.

I like the idea though, as you say it makes rear brake options a lot more simple once fitted.
Just as long as the MOT people are happy with it, it's a great idea.

[twoqu]

Looked at this a while back when I saw that there was a replacement for the RR drum trans brake (X disc?). Also popular in the US for Street rods etc when using transplanted axles.
I would say well worth looking into providing:
1. It performs as well or better than stock.
2. Its cost effective.
It will not be subjected to heat soak and if people really want to do handbrake turns then they can configure an hydraulic hand brake as the MOT should be satisfied with the mechanical one.

[twoqu]

Of course one major disadvantage is that it will be more or less useless as an emergancy braking system, i.e. if you suffer a brake failure as the size and pad material will be inadequate. Might just be adequate as a handbrake!

[rj scotty]

A total failure on a tandem system is highly unlikely, but a valid point nonetheless.

[Ian Simmonds]

Being a bit of a Luddite here, but wouldn't it be easier to just check , maintain and service the rear callipers annually?

[rj scotty]

The rear set up works fine if maintained.
It's the rear brake options this opens up thats the USP.

Porsche rear callipers can be had for cheap on the bay of thieves