Fuso FG front differential locker question ?

[mog]

I'd guess that by the time an ATB/LSD/Locker has been installed in the front differential, the operator has already gone to Super Singles and would probably be using 35”+ tires. So all the feedback would be on those, correct ?
-
So are these the pluses and minuses of each system? Did I miss something, or get something wrong?
ATB/LSD
+ always available when front diff is selected
+ smooth application of torque to both wheels
+ can be used in less ‘extreme' conditions
+ fine for on-road (snow) use
+ 100% of torque (variable % to each wheel)
-
Locker (air, electric, manual)
+ 100% of torque (50% to each wheel) when selected by operator
+/- Driver decides when engaged
+ will operation with one wheel in the air
- difficult operation in a turn unless extreme terrain slippage
- general only used in extreme conditions
- added system need depending on engagement system (compressor, air line, switches, wiring, linkage, etc)
- added engagement systems susceptible to off-road damage
- not available for the Fuso FG

 

[pugslyyy]

At the risk of being controversial, let me equate a manual locking diff with a manual transmission, and an automatic locking diff with an automatic transmission. For a lot of conditions, and for a lot of drivers, automatics are the best choice. For a skilled driver who needs complete control, a manual is going to be their first choice.

The advantage of driver controlled lockers is that the driver knows definitively when each axle is locked or not - no guesswork. There are certain situations where you don't want to be locked or fully locked (off camber, hill climbing).

For me it all comes down to the specific application, and who the driver is going to be.

 

[whatcharterboat]

Hi Mog,

I would like to clarify a couple of things here please.

I’d guess that by the time an ATB/LSD/Locker has been installed in the front differential, the operator has already gone to Super Singles and would probably be using 35”+ tires. So all the feedback would be on those, correct ?

I dont know how that rumour started about them not handling big wheels but I don't think that way at all. The diffs we use are really strong. That's why they give us a lifetime warranty on them. I would think the FG axles or tailshaft would give up well before the diff ever would.

-
So are these the pluses and minuses of each system? Did I miss something, or get something wrong?
ATB/LSD
+ always available when front diff is selected
+ smooth application of torque to both wheels
+ can be used in less ‘extreme’ conditions
+ fine for on-road (snow) use
- will not operation with one wheel in the air ?
-
Locker (air, electric, manual)
+ 100% of torque (50% to each wheel) when selected by operator
+/- Driver decides when engaged
+ will operation with one wheel in the air
- difficult operation in a turn unless extreme terrain slippage
- general only used in extreme conditions
- added system need depending on engagement system (compressor, air line, switches, wiring, linkage, etc)
- added engagement systems susceptible to off-road damage

Next thing I want to explain further is their operation if one wheel is in the air. The way they work is that torque from the wheel that has the least grip is multiplied into the wheel that has the most grip. Thats paraphrasing in very simple terms but if there is zero grip or torque bias, there is nothing to multiply and the loose wheel will spin freely in the air......exactly the same as an air-locker would before you engage it. With an ATB, to engage it when one wheel is hanging, you need to tap the brakes slightly to regain some resistance and return the torque bias then the torque is re-applied to the wheel with the most grip and away you go. So in that respect it is still very effective , it's just that it requires engaging or selecting just as an air-locker would but instead of a switch you have to tap the brakes.

You also stated that an air-locker has 100% of torque (50% to each wheel) when selected by operator. Correct but an ATB also applies 100% of torque but instead of only being able to lock at 50% to each wheel, an ATB will seamlessly provide whatever amount of torque is required to the wheel that has the most grip and remove torque from the wheel that has the least grip. So as an example, travelling on a track with a muddy rut down one side, the torque split might be 70% to the wheel on the dry track and only 30% to the wheel in the mud. Check out the videos on youtube. There are some that explain typical ATB or Torsen operation very clearly with animation.

All this aside, the biggest minus for an air-locker or e-locker was not on you list ........Not available for an FG.

I think I said before that ATW did look at developing different types of lockers as a joint venture with a major locker manufacturer (and we approached several) but believe 100% that an ATB was the best option for the FGs.

 

[alan]

I'd guess that by the time an ATB/LSD/Locker has been installed in the front differential, the operator has already gone to Super Singles and would probably be using 35”+ tires. So all the feedback would be on those, correct ?
-
So are these the pluses and minuses of each system? Did I miss something, or get something wrong?
ATB/LSD
+ always available when front diff is selected
+ smooth application of torque to both wheels
+ can be used in less ‘extreme' conditions
+ fine for on-road (snow) use
- will not operation with one wheel in the air ?
-
Locker (air, electric, manual)
+ 100% of torque (50% to each wheel) when selected by operator
+/- Driver decides when engaged
+ will operation with one wheel in the air
- difficult operation in a turn unless extreme terrain slippage
- general only used in extreme conditions
- added system need depending on engagement system (compressor, air line, switches, wiring, linkage, etc)
- added engagement systems susceptible to off-road damage

Hi Mog, when i get a chance i will dismantle one of our diff centres and post some pic's, so you can see how they work with the spring tension, this avoids the the brake pedal asistance.

 

[Amesz00]

Hi Andrew, how's married life? normally the toys are the first thing to go
I don't know about can't take the strain of large tyres but there's only one way to find out, i have seen your driving on youtube mmm i don't know! yes with spring load it will always deliver drive to the wheels obviously the amount will vary check out youtube, torsen LSD there is a lot of good video's on this type of diff centre.

Alan, yea married life is pretty good mate. Haven't had to sell the truck yet haha
Didn't know my driving was on youtube?? Hope its not too embarrassing haha.. well it may be a bit crazy sometimes but I've managed to not break anything other than wing mirrors as yet.. and I do have a good amount of mech sympathy.. I think.
Anyways..
Aren't torsen diffs what's in those Swiss duro trucks? They meant to be real good offroad. Heard from one fellow that said he'd driven them, + they were even better than a mog offroad...
Do you or John know the torque ratio of your diffs?

 

[mog]

John,
Thanks for all the added info. I've updated the 'list'. The ATB diffs sure sound like the 'Hot Tip'.
Alan,
So it sounds like the ATW ATB diffs are one style/type and yours are another style/type ?

 

[alan]

Alan, yea married life is pretty good mate. Haven't had to sell the truck yet haha
Didn't know my driving was on youtube?? Hope its not too embarrassing haha.. well it may be a bit crazy sometimes but I've managed to not break anything other than wing mirrors as yet.. and I do have a good amount of mech sympathy.. I think.
Anyways..
Aren't torsen diffs what's in those Swiss duro trucks? They meant to be real good offroad. Heard from one fellow that said he'd driven them, + they were even better than a mog offroad...
Do you or John know the torque ratio of your diffs?

Hi Andrew, I'm not sure about the Duro trucks using this type if diff, but it's a very popular type of LSD in front diffs, our's has a TBR of approx 3:1
Alan

 

[Bandicoot]

Our EarthCruiser has the TrueTrac LSD from Hart's Transmissions fitted (to the front axle). We had a problem initially but it has performed flawlessly for the past two years, including completing the bottom half of the Canning stock route and many other tough tracks here in Oz over that time. We are currently on Moreton Island for 10 days (pic below), but largely camped up in the one spot so the diff isn't getting much of a workout at present!
We are running 17 inch rims with Wrangler MT/R 37x12.5 tyres (and the Kevlar sidewalls), which are rated as 1600 kg at 50 PSI, which is a high load for a low pressure compared to (say) our original Michelins on 16 rims. Personally I think low tyre pressures (we are running about 18 psi cold here in the sand) is far more important than an LSD in sand; however, on very rough tracks the front LSD, when combined with what is already an excellent rear LSD and the very low low range on the Canters, makes it almost unstoppable. I have been stuck in mud a few times before fitting the front LSD. I haven't since, but I'm sure it will still be an issue in deep enough mud! That's when I get the Maxtrax out.
Rick

 

[SkiFreak]

I am guessing that you do not have a problem with swooping magpies Rick.
That's a lot of antennas bud...

 

[Bandicoot]

Well SkiFreak we have Codan NGT HF (the whip is actually removed in that pic but you can see the large autotune base on front left of vehicle) plus UHF plus AM/FM radio plus hands free mobile (CELL) phone plus mobile data link which tunes in to the cellular carriers and links to our wireless modem. The BGAN phone & data satellite system (Hughes 9202) unit is inside and deployed as necessary so no 'aerial' showing for it! And they all get used. I even carry some critical spare aerials for when they inadvertently get wiped out which shouldn't happen as they are all detachable but due to laziness or inattention it does occasionally happen. I carry a very short stumpy rubber ducky type aerial for UHF in close bush work. I also have a portable shortwave set (Sangean ATS-909X) for listening to the news and current affairs!!
rick

 

[PST]

We also have a front LSD for canters, the front diff centre is the same on all model Canters, our's is a gleeson torsen style LSD same as the Quaife and truetrac versions, they sell for $1900, if you send us the centre we fit them for free.

Alan, I'd like to find out current details of the Diff, price and if you are still fitting, where does it need to get to?

 

[SkiFreak]

where does it need to get to?

Alan runs a 4x4 business in Melbourne.
I would suggest that you PM him if you need specific information.

 

[alan]

Alan, I'd like to find out current details of the Diff, price and if you are still fitting, where does it need to get to?

Hi, You can contact me at alan@outbackaccessories.com

 

[alan]

We still have LSD and electric 100% locker front diffs available, also the forged alloy super singles 16" and 17"

 

[sumnrfam]

We still have LSD and electric 100% locker front diffs available, also the forged alloy super singles 16" and 17"

Alan, ,, email sent re: the 16" singles, thanks