Audi R10 (or other LMP or GT) cassette type gearbox

[chernaudi]

I've been watching some videos on YouTube about the 2006 24 Hours of Le Mans (which I also watched live) and they did a gear cluster change on the #8 Audi in about 8 minutes (a bit longer if you add the normal servicing they did to the car). I had also read in a Car and Driver article on the R10 from earlier in 2006 that the R10 used a cassette type gearbox to combat the ACO's restrictions on quick change rear ends like what the R8 used.

Of course, I'm wondering how a cassette type assembly works, and namely, how one would work that doesn't require removal of the gearbox casing from the car. I know that on other cars the gearbox casing would have to be removed to access the transmission/diff gear clusters. But on the R10, they were able to change those parts with the gearbox in situ and still attached to the car.

And are there other examples of this on more recent LMP or GT cars?

[hoffman66]

Cassette boxes have been commonplace on racing bikes for decades, it simply means on those, you can remove the cluster without having to remove a gearbox, or in a small capacity class like 125 or 250, the entire engine as on bikes the engine and box are like a Mini, all one unit.

[tux]

Hello Mr Chernaudi.

For once i can be a help to this forum.

A cassette type gearbox just means that the internals of the gearbox are one unit and can be removed from the gearbox casing without having to remove the gearbox from the car. Ideal for ratio changes and gearbox issues.

You end up with something like this.


I think most prototypes, single seaters and GT cars use this approach now because you cant change the gearbox casing in most series but most series will allow you to change the internals. Infact, im sure we saw this a couple of times in last weekends Daytona 24 hours.

[chernaudi]

I wonder how they did this on the R10 for example, since it has the differential behind the transmission section of the transaxle?

[Tony C]

Originally Posted by chernaudi

I wonder how they did this on the R10 for example, since it has the differential behind the transmission section of the transaxle?

I havent seen the car in question but you could have the cassette come out the side of the gearbox housing.

[chernaudi]

That works fine on a transverse gearbox, but the R10 (as far as I know) used a longitudinal gearbox with the diff behind the transmission assembly.


Would what you pointed out work on such a longitudinal gearbox?

[chernaudi]

Got this one answered on the Mulsanne's Corner Facebook page. The R10's gearbox in a lot of ways was the predecessor to the current XTrac P1011 Indy Car gearbox.

In this photo, the dark colored panel is where the transmission internals and maybe the differential are accessed from.