Locked or spool differentials

[autogyro]

A spool is no differential..it locks the two wheels together .. THIS is a spool
http://www.stradsplace.com/photos/spool.jpg

Indeed it is strad, add a ring gear and pinion to it and you have a spool differential.

[strad]

If you castrate a bull, obviously it is no longer a bull. It is a steer. But according to your logic it should be called a bull steer. Can't be both things, just like a spool diff.

.
YES, YES, exacly. It's not a differential at all.
There is no difference in the input to or the output of either wheel. No difference = no differential.

[autogyro]

If you castrate a bull, obviously it is no longer a bull. It is a steer. But according to your logic it should be called a bull steer. Can't be both things, just like a spool diff.

.
YES, YES, exacly. It's not a differential at all.
There is no difference in the input to or the output of either wheel. No difference = no differential.

Hahaha
The assembly does differentiate between the pinion input and the 'two' drive outputs though doesnt it
Go on Go on Go on hahaha

[PhillipM]

Final drive, perhaps, not a differential. Unless you count the whole gearbox as a differential...

[autogyro]

Final drive, perhaps, not a differential. Unless you count the whole gearbox as a differential...

Sometimes the differential is also the gearbox as in the Alfa bi motor.
This had a strait eight engine in the front and another in the back, a gearbox in the middle and two diagonal drive shafts to each rear wheel.
I consulted with Tony Rudd on one of these when they were trying to work out the engine and chassis mounts.
It sits in a museum.
What would you call the final drive on that car?

[autogyro]

https://www.youtube.com/watch?v=ME3m1Rz2RzE

The first ever Ferrari.
I looked over this car with Tony Rudd (ex ERA BRM and Lotus) and helped with the engine mounting and alignment.
In a museum now.

[strad]

Let me see . . . perhaps because in common parlance a "diff" is "a big cast iron thing that keeps the rear wheels apart".

No..That's the third member and or the pumpkin.

[mrluke]

If a door is a little bit open it is a jar. How can it be both a door and a jar !?

[strad]

[Jersey Tom]

You guys can't possibly, seriously be arguing this. If someone says a car's got a "spool" or a "spool diff" or a "locked diff" you know exactly what they're talking about. The end.

Just the same if you ask someone how much air pressure they have in their tires and they say "thirty pounds." Do you stand in there in disbelief, shocked, mouth agape, stuttering "but... but... I asked for a measurement of pressure and you replied in MASS or FORCE. HOW CAN THIS BE?!?!? IT DOESN"T ADD UP!!!"

[gruntguru]

A voice of reason. Thanks Jersey Tom.

[autogyro]

A voice of reason. Thanks Jersey Tom.

I agree GG for most people the basic workings of a geared differential in a conventional axle are strait forward.
Understanding the use of a spool, locked diff, locker or ratchet diff and slipper diff is also fairly easy.
It is when you consider torque vectoring differentials that The principles become more important.
There are development directions available from gearboxes and final drive systems that could net more performance gains than from any engine development.
Unfortunately today we have a spec formula that prevents any work in this direction.