What did you do to your Puma today?

DiscoMick · 3rd February 2018, 09:39 AM

Originally Posted by tact

An ATB is an ATB. Regardless whether its positioned between left/right axles (replacing front/rear diff centres), or positioned between front/rear prop shafts (replacing centre diff centre).

With the Ashcroft centre ATB installed - the CDL still operates as it does normally. This is of course essential due to the way an ATB works (i.e. when there is no torque on the driveline it behaves like an open diff)

"No torque on the driveline" is a situation that routinely happens when one side of a diff is free-spinning (e.g. wheel in the air), or whenever there is no drive being applied to the driveline (throttle neither driving or trailing, or transmission in neutral).

It'd be really nice if the front/rear diffs were also lockable when an ATB is installed since they too act as open diffs in a "no torque" situation. Having traction control does mitigate this.

If you have TC to stop wheels from spinning, do you see any advantage in an ATB?

Tombie · 3rd February 2018, 09:45 AM

Originally Posted by DiscoMick

If you have TC to stop wheels from spinning, do you see any advantage in an ATB?

Absolutely.... there are times when fully locked induces understeer..

**rick130** · 3rd February 2018, 10:16 AM

Originally Posted by DiscoMick

If you have TC to stop wheels from spinning, do you see any advantage in an ATB?

TC + ATB is at a rough guess 95% as capable as a fully locked axle off road while still having steering and probably reducing crabbing on side slopes.

**1nando** · 3rd February 2018, 10:53 AM

Originally Posted by filcar

About $2500 supplied and fitted for the ATB front and rear, hard to split out the cost of the centre diff as other work was done at the same time but the centre diff cost around $1200 plus whatever the labour is for removal and refit of transfer case etc, all work done

by Les Richmond Automotive as they carry most of the Ashcroft gear in stock on the shelf.

Please tell me that you did your out put shaft at the same time???

**1nando** · 3rd February 2018, 10:56 AM

Originally Posted by rick130

TC + ATB is at a rough guess 95% as capable as a fully locked axle off road while still having steering and probably reducing crabbing on side slopes.

I dont want to argue your statement but rather mention that the ability to select when to engage your lockers is in my opinion a better option than atb diffs in the front and rear. I had the centre diff atb with elockers front and rear and this was in my opinin the perfect setup. I know it costs more but the ability to lock a particular axel when needed is great.

**Vern** · 3rd February 2018, 11:14 AM

Originally Posted by rick130

TC + ATB is at a rough guess 95% as capable as a fully locked axle off road while still having steering and probably reducing crabbing on side slopes.

Don't know if you remember the Haultech mogrover (pretty sure it was mog rover) with their home made traction control, they ran this without lockers and claimed it was 98% as good. Was a pretty sweet tuff truck in the day

**filcar** · 3rd February 2018, 11:59 AM

Originally Posted by 1nando

Please tell me that you did your out put shaft at the same time???

Sure did

**martnH** · 3rd February 2018, 12:40 PM

Just theoretically...
Say, a defender with front and rear ATB going steep and uneven down hill.

One side of wheels will have more traction so the ATBs will bias the torque to the other side, right? Will this will rotate the vehicle and may result in a roll over? In this case, an unlocked diff will be better?

P.s. about to get all three ATBs

Cheers

**tact** · 3rd February 2018, 03:43 PM

Originally Posted by DiscoMick

If you have TC to stop wheels from spinning, do you see any advantage in an ATB?

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.

**tact** · 3rd February 2018, 03:58 PM

Originally Posted by martnH

Just theoretically...
Say, a defender with front and rear ATB going steep and uneven down hill.

One side of wheels will have more traction so the ATBs will bias the torque to the other side, right? Will this will rotate the vehicle and may result in a roll over? In this case, an unlocked diff will be better?

P.s. about to get all three ATBs

Cheers

What I do in that circumstance is feather the brakes to provide a bit of preload on the driveline. Let antistall drive against light brake pressure downhill.

Need to do this with open diffs too. If you don’t and a wheel loses traction completely , the other wheel on that axle is useless to you also, as far as retardation goes. (Open diff or ATB )You can end up with a runaway. (And if you had a centre ATB and centre diff unlocked - a single wheel losing traction up or down hill will unload ALL 4 wheels! Always lock the centre diff on steep up/down slopes!)

(edit: just to add - regardless open, fully locked, ATBs or TC the peril of going sideways with one side having traction and one side without is the same. You just need to always be ready to hit throttle to keep the pointy end downhill)

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