Thread: What did you do to your Puma today?

Originally Posted by tact

Absolutely. Plenty of guys write that once they install ATBs they rarely see TC activate. (About the only time TC is needed will be with a wheel in the air - where ATBs are useless)

The ATBs are way more “proactive”, doing their thing while we there is load on the driveline.. whether in the bush or the morning commute. No input or attention required.

Comments about selectable lockers being more desireable because they are selectable (can be turned off) are misguided. (1Nando - were you thinking of Detroit’s aka Aussie lokkers?). ATBs never “lock” so never suffer from not being able to be turned off.

I dont mean atbs are selectable i mean elockers which are selectable and is what i had front and rear. The only atb i had eas in the centre diff
I prefer selectable lockers rather than atbs which work when theres slip. Each to thier own

Had clutch replaced under warranty (noisy due to springs being fubar) and red front seatbelts.

Originally Posted by martnH

Thanks the last bit is what I meant

Downhill very slippery and you have to accelerate to maintain steering control

Will the ATB works against this?

Nope. You’ll be fine. I have done some long slippery downhills with my barge (trips into the Malaysian rainforest during 3yrs I had it there - haven’t struck that yet here since moving back to Oz). Just point the front wheels where you want to go and blip the throttle to turn that way.

Having had full lockers..
I’d go ATBs any day....

Originally Posted by 1nando

[...]I prefer selectable lockers rather than atbs which work when theres slip. Each to thier own

See that’s where ATB action is often misunderstood: ATBs don’t “work when there’s slip”, not in the sense that slip is needed before they work. (That’s more like TC, detects slip then brakes a wheel)

Imagine instead you had to slide a bolt on a gate latch. But someone is pushing on the gate causing the bolt to bind up and resist moving. If there is no weight in the mechanism the bolt slides no worries, no effort at all.

Thats how ATBs work. When there is weight on the driveline the helical gears bind up more inside their pockets even when no “slip” is present - Eg. when travelling in a straight line.

Ie. before there is even a hint of “slip” the ATB is already ready to resist any tendency for either half shaft to rotate at different speeds.

When there is a difference in rotational speed of half shafts (or wheels), such as turning or slip is present, then the helical gears rotate in their pockets (reluctantly due to the weight/torque on them and friction against their pocket). This friction then makes it hard for the half shafts to rotate at different speeds.

Think of ATBs as simply open diffs that are not very good at being diffs. They bind up internally whenever there is some weight on the driveline.

I think I understand how an ATB would work cross axle, particularly since my previous D1 had a rear Detroit auto locker.
However, what about a centre ATB? Is it kind of like a way of varying the front-rear torque split infinitely depending on load, compared with it being open or locked 50:50? When is that most useful?

It’s exactly like a normal diff turned 90 degrees..

Originally Posted by DiscoMick

I think I understand how an ATB would work cross axle, particularly since my previous D1 had a rear Detroit auto locker.
However, what about a centre ATB? Is it kind of like a way of varying the front-rear torque split infinitely depending on load, compared with it being open or locked 50:50? When is that most useful?

Just think of the front/rear prop shafts (with centre diff between them), as you would think of the left/right half shafts on a regular axle (with a regular diff between them)