Help with differential

[cairncross]

Hi Guys

I have started to build a chassis for my electric car (Lotus Seven type but with Subaru suspension bits and fork lift motor) and I have discovered that my Subaru diff is asymmetric.

It has the engine drive-line offset about 30mm to the drivers side (NZ) (we sit on the right)

The diff and drive shafts are on the center line, both wheel drive shafts are the same length

I am thinking about inverting it,
The rear diff cover with the mounts and breather is symmetrical so it can stay the correct way up,

This will move the drive-line (and the motor) over to the passengers side giving me more room and helping the balance when I am on my own.

This is important as I am using direct drive and keeping the motor behind the firewall so that I can use the engine bay for batteries

This means the motor is between my legs and my passenger's legs

This will require me to run the motor the other way so I will have to re-advance the motor!!

Is there any reason why I should not do this??

Was this not a common mod on VW gearboxes to change from a rear engine to a mid engined layout??

 

[pontiacjack]

I have to assume that the third member uses hypoid ring and pinion gears, correct? If so, inverting it (and thus running it backwards) would not provide satisfactory service (nor service life). Take a look at how assymetrical the ring gear teeth are. They were never intended to serve for any extended period running "in reverse".

 

[GregLocock]

Keep the diff the right way up and offset it and adjust the halfshafts to suit.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[YvesLLewelyn]

They did invert VW gearbox/diffs to reverse the output axle direction of rotation but the engine and diff stll rotated in the same direction (relatively speaking) so the correct side of the meshing teeth were still engaged. Reversing the electric motor's direction of rotation will load the "wrong" side of the teeth (as Pjack says). In something very light and low-powered you might get away with it OK (or you may not).

 

[cairncross]

Hi guys,
Thanks for your input
I have decided to keep the diff the right way up,
Put the motor on the C/L
Have the drive-shaft at about 6 degrees horizontally
(shaft will be about 300 mm between joints)

Thanks for your help in this

I will be back with my next problem when I find it!

Duncan