Fuso FG front differential locker question ?

[mog]

Is the front locker offered by ATW HERE (2/3[sup]rds[/sup] down the page) the same as then Detroit Truetrac offer by Hart Transmissions HERE ?
The ATW locker is listed as "2008 and newer", so not luck for 2007 and earlier Fuso?
What about the Truetrac from Hart, does anyone know if this is available for pre-2007 (aka:2002) FGs ?
Has anyone looked into getting a manual front locker (air like ARB or electrical like an Eaton) 'adapted' to work in an FG?
Thanks,

 

[eMULe]

I have a front 'torque biasing differential' from ATW/Sportsmobile. It is a helical gear limited slip like the Hart/Eaton in the link. It was made by a motorsports supplier in the UK with an international reputation. I would expect the Hart/Eaton unit to be similar. Relative hardness and heat treat of components is important. It works by friction. It is installed in the front of a 1993 US FG439. When I was worried about tearing mine apart only to find the supplied unit wouldn't fit my old one, I was told that the front dif. carrier is the same across the years. It fit fine. While a true locker would be nice, I wouldn't want a Detroit Locker type in a front differential. An ARB or other selectable one would be ideal but I'm not aware of any suppliers.

 

[LeishaShannon]

Its listed as part "QDH20B" in the Quaife UK 2013 catalog found here: http://dolf1cqamvncp.cloudfront.net/Quaife-Cat-2013_web.pdf
The Isuzu NPS 300 part is "QDF5I".

 

[pugslyyy]

I have a front 'torque biasing differential' from ATW/Sportsmobile. It is a helical gear limited slip like the Hart/Eaton in the link. It was made by a motorsports supplier in the UK with an international reputation. I would expect the Hart/Eaton unit to be similar. Relative hardness and heat treat of components is important. It works by friction. It is installed in the front of a 1993 US FG439. When I was worried about tearing mine apart only to find the supplied unit wouldn't fit my old one, I was told that the front dif. carrier is the same across the years. It fit fine. While a true locker would be nice, I wouldn't want a Detroit Locker type in a front differential. An ARB or other selectable one would be ideal but I'm not aware of any suppliers.

That's my thoughts... I have a hard time seeing a good application for a solid locking front diff in an expedition vehicle - just too much opportunity for carnage. clutch-pack based or a high-tech ABS soft-locker style might be okay. ARB on/off for the rear can be very nice (stops it from dragging you down a hillside when you don't want it engaged).

I've had an ARB in my 110 (Salisbury) rear and it is bulletproof. Still open diff up front and not sure I would want anything different.

 

[alan]

Is the front locker offered by ATW HERE (2/3[sup]rds[/sup] down the page) the same as then Detroit Truetrac offer by Hart Transmissions HERE ?
The ATW locker is listed as "2008 and newer", so not luck for 2007 and earlier Fuso?
What about the Truetrac from Hart, does anyone know if this is available for pre-2007 (aka:2002) FGs ?
Has anyone looked into getting a manual front locker (air like ARB or electrical like an Eaton) 'adapted' to work in an FG?
Thanks,

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.

 

[whatcharterboat]

Is the front locker offered by ATW HERE (2/3[sup]rds[/sup] down the page) the same as then Detroit Truetrac offer by Hart Transmissions HERE ?
The ATW locker is listed as "2008 and newer", so not luck for 2007 and earlier Fuso?
What about the Truetrac from Hart, does anyone know if this is available for pre-2007 (aka:2002) FGs ?
Has anyone looked into getting a manual front locker (air like ARB or electrical like an Eaton) 'adapted' to work in an FG?
Thanks,

Hi Mog,

Ill try to get the wording on the website fixed up.

No they are definitely not the same as the Detroit offering however ATW sells the Auto Torque Bias diffs for all model FGs and another ATB unit for all model NPSs. They fit great and work great.

The guys that make them for us give a lifetime waranty on this part and have been building these ATB- style diffs for many many years and for a wide variety of applications....mainly Motorsport but also for military 4x4 trucks. The Fuso and Isuzu units however were developed jointly with ATW and we began solely marketing them a couple of years ago. Prior to this venture, we looked long and hard at air lockers, e-lockers, various LSDs and Torsens. As no one at that time offered anything for FGs....remember this is a very very limited market....we then approached all the major manufacturers offering to cover tooling costs in advance to drive some type of solution. I have no doubt we made the right decision to go the way we did.

If you want an opinion from one of our customers with an old Canter that was fitted one of these diffs read this testimonial here This is exactly the same unit that is sold through ATW USA.

Our local FUSO dealer allows a safe 7 hours to fit one but if you really know what you're doing, you can get that time down a bit. We supply new carrier bearings with the diff centre even on a brand new truck cause you're likely to damage the old ones if you tried to re-use them. In that photo on the ATW USA page you can see the OEM diff centre that has been removed still has the old bearings left on. They are easy to lap in with big adjuster nuts on either side of the carrier. You can still see the Bearing Blue on the crown wheel. Actually I took the photo on that page at the FUSO dealers just after we lapped it in. That was the initial pre-production prototype you see there that was fitted to the Tan ATW R&D truck. We had to make sure the fitted tolerances were correct then checked operation before committing to a production run ........that prototype is still going strong after plenty of abuse offroad and extra torque from the Allison tranny.

I should add that there is no modification required to install them as it is a direct replacement centre. Also there is no special lubrication required as they don't generate heat like a typical LSD so they simply run the same oil as the OEM open diff.

As a matter of interest for ISUZU readers , the NPS front diffs are a little trickier to lap as they're shimmed.

Regards
John.

 

[mog]

Thanks !
-
eMULe, thanks I’d say beside your experience and whatcharterboat‘s below that it sounds like all the FG front differentials are the same, so the ‘year issue’ in not a factor.
How have you liked yours in the real world? Have you used it in the snow (either on-road, off-road or both)? I’m guess that our Aussie brothers don’t get to do that often.
(OT-does it snow in Australia, or just sunshine and shrimp on the barbie twelve months of the year ?)
Was yours installed by a local to you shop, any troubles with that?
-
LeishaShannon, wow that is one heck of a catalog, thanks! I never knew there were so many cool transmissions and differentials. I think I need about 4 more cars just to use 1/50[sup]th[/sup] of their cool products.
-
pugslyy, very good point you have. I’ve only had experience with open front diffs (F350s and FJ40) manual mechanical locking diff (Unimog) and AWD systems (XC90 and Audi TTs). The AWDs perform great in the snow on paved roads, but those are pretty much comparing apples to bananas systems. I loved the locking front diff on my Unimog, but a Fuso is not a Unimog. How does the LSD front diffs perform on paved snow cover roads? Do you get ‘pulling’ as they lock and unlock? This is where my biggest concern would be with an LSD front diff without personal experience. I take my Fuso to the Oregon dunes, so increasing perform in sand (which can be deep and soft depending on the time of year) would be a big plus for me. How does an LSD compare to a locked front diff in that terrain?
-
alan, who are your Fuso parts sold by in the USA? I’ve seen that EC sells your bling wheels in the USA. Do they handle all you parts on this side of the pond?
-
whatcharterboat, Thanks. I sure like all the research and testing ATW puts into all their products and vehicles. That is a huge piece of mind to me. Do you feel that a Fuso dealer without experience in installing these could do it well, or is there a need to go to one that has experiences with these? And I guess my recurring question, do you have any feedback with the use of these in snow on paved roads?
-
Again, thanks to all for the feedback/information

 

[fg4oz]

I had one installed for my wife's birthday. We went to Fraser over the new year period and the sand was very soft. I wasn't sure what to expect with how it would go, but it did really well through the inland tracks. I never did much sand driving before it was installed in this truck. Tyre pressure surprised me. I read the charts as to what the recommended pressures should be, but we couldn't get through most places unless we dropped down to around 20-25psi and getting the biggest run up through Indian Head. I'm still glad we added the ATW ATB front diff to our fg649.

 

[whatcharterboat]

Thanks !
-
whatcharterboat, Thanks. I sure like all the research and testing ATW puts into all their products and vehicles. That is a huge piece of mind to me. Do you feel that a Fuso dealer without experience in installing these could do it well, or is there a need to go to one that has experiences with these? And I guess my recurring question, do you have any feedback with the use of these in snow on paved roads?
-

Hi Mog,

Firstly, the diff is a direct replacement. Any FUSO dealer or mechanical workshop with 4wd experience should have no trouble removing a diff and refitting a new one. There is nothing more complicated than if they were replacing an old diff with a new OEM diff centre. The machine shop that manufactures them for us also make Formula 1 components. That should give you an idea of the quality assurance procedures and tight tolerances.

Honestly I have no feedback regarding snow. We do have snow here but it is very wet cause it just doesn't get cold enough. I can say that there is virtually no noticeable steering effect or steering snatch or that feeling like your on railroad tracks and can't steer!! ATB diffs are hugely popular in front wheel drive race cars and 4wd rally cars for that reason.

I know they are sometimes referred to as a LSD but "limited slip" is probably not a good description. The auto torque bias action is still similar to an open diff in that with both wheels off the ground you can freely spin the wheels in opposite directions. So when steering around a turn the outside wheel can turn at a different speed to the inside wheel ......but the difference with an ATB diff being that the torque lost on the side with the least grip is multiplied to the side with the most grip and it is a smooth, seamless , progressive and proportional shift of torque rather than a typical LSD with full drive to both wheels and a clutch packs that suddenly releases when too much friction occurs.

Their performance in sand is definitely what we receive the most feedback with and that has been great as I mentioned before. FYI we are now pushing these diffs into the rural fire services that operate in sandy regions and they do very heavy product testing beforehand.

Did you read that testimonial?

Thanks mate,

kind regards,
John

 

[whatcharterboat]

I had one installed for my wife's birthday.

Hahaha!! Good on ya bloke. Hahaha.

I read the charts as to what the recommended pressures should be, but we couldn't get through most places unless we dropped down to around 20-25psi and getting the biggest run up through Indian Head.

Dont feel too bad. Everyone else with 19.5's had to do the same. I think the conditions on Fraser last Xmas were some of the worst I've experienced in 40 years. A few months of dry and all the extra traffic and the sand just turns to bottomless powder. How rough were the inland tracks!!! We're you up there around the 5 th or 6 th of Jan ? Did you hear about that Dodge Ram that got pushed straight out into the surf as he tried to cross Eli. I saw it on the tilt tray going back on the barge. Not pretty. Mostly Eli is only a couple of 100mm deep but that day it was over the bonnet of a lot of 4bys .

 

[alan]

Thanks !
-
eMULe, thanks I'd say beside your experience and whatcharterboat‘s below that it sounds like all the FG front differentials are the same, so the ‘year issue' in not a factor.
How have you liked yours in the real world? Have you used it in the snow (either on-road, off-road or both)? I'm guess that our Aussie brothers don't get to do that often.
(OT-does it snow in Australia, or just sunshine and shrimp on the barbie twelve months of the year ?)
Was yours installed by a local to you shop, any troubles with that?
-
LeishaShannon, wow that is one heck of a catalog, thanks! I never knew there were so many cool transmissions and differentials. I think I need about 4 more cars just to use 1/50[sup]th[/sup] of their cool products.
-
pugslyy, very good point you have. I've only had experience with open front diffs (F350s and FJ40) manual mechanical locking diff (Unimog) and AWD systems (XC90 and Audi TTs). The AWDs perform great in the snow on paved roads, but those are pretty much comparing apples to bananas systems. I loved the locking front diff on my Unimog, but a Fuso is not a Unimog. How does the LSD front diffs perform on paved snow cover roads? Do you get ‘pulling' as they lock and unlock? This is where my biggest concern would be with an LSD front diff without personal experience. I take my Fuso to the Oregon dunes, so increasing perform in sand (which can be deep and soft depending on the time of year) would be a big plus for me. How does an LSD compare to a locked front diff in that terrain?
-
alan, who are your Fuso parts sold by in the USA? I've seen that EC sells your bling wheels in the USA. Do they handle all you parts on this side of the pond?
-
whatcharterboat, Thanks. I sure like all the research and testing ATW puts into all their products and vehicles. That is a huge piece of mind to me. Do you feel that a Fuso dealer without experience in installing these could do it well, or is there a need to go to one that has experiences with these? And I guess my recurring question, do you have any feedback with the use of these in snow on paved roads?
-
Again, thanks to all for the feedback/information

Hi Mog,
Our LSD is available from Earthcruiser or direct from us, no matter who's diff you look at they are all based on a Gleeson torque sensing unit developed originally for the audi quattro's, some manufacturers have made improvements to this original design over the years, our unit also features spring tension to give the unit some inbuild friction so there is never any complete loss of traction, without this one wheel can be in the air and receive no drive at all, fitting is straight forward we can reuse the original carrier bearings if the centre is new or if second hand always fit new carrier bearings as these can fail, which we had happen to a fraser island tour bus, after about 6months of constant use the carrier bearings failed and damaged the LSD, it was'nt a unit we fitted so we had no idea of the installation, hence the reason we now offer free fitting for centres that are freighted us.
The main benefit of this type of LSD is the smooth transfer of drive which is beneficial in a front drive situation and no clutch packs to wear out.

 

[mog]

Honestly I have no feedback regarding snow. We do have snow here but it is very wet cause it just doesn't get cold enough. I can say that there is virtually no noticeable steering effect or steering snatch or that feeling like your on railroad tracks and can't steer!! ATB diffs are hugely popular in front wheel drive race cars and 4wd rally cars for that reason.
I know they are sometimes referred to as a LSD but "limited slip" is probably not a good description. The auto torque bias action is still similar to an open diff in that with both wheels off the ground you can freely spin the wheels in opposite directions. So when steering around a turn the outside wheel can turn at a different speed to the inside wheel ......but the difference with an ATB diff being that the torque lost on the side with the least grip is multiplied to the side with the most grip and it is a smooth, seamless , progressive and proportional shift of torque rather than a typical LSD with full drive to both wheels and a clutch packs that suddenly releases when too much friction occurs.

John,
Thanks for the description, I think I see the light now. Very good point about being used by rally cars, they surly would not want a diff that effected steering. It sounds like an ATB diff might even be better then a locking (air or electric) diff since it would be used 100% of the time when in 4 wheel drive. I know at least in my Unimog I did not want to 'lock' the diff except when absolutely needed as when locked it effect steering so much.
I guess I know what to get my girlfriend for her birthday :sombrero:

Our LSD is available from Earthcruiser or direct from us, no matter who's diff you look at they are all based on a Gleeson torque sensing unit developed originally for the audi quattro's, some manufacturers have made improvements to this original design over the years, our unit also features spring tension to give the unit some inbuild friction so there is never any complete loss of traction, without this one wheel can be in the air and receive no drive at all, fitting is straight forward we can reuse the original carrier bearings if the centre is new or if second hand always fit new carrier bearings as these can fail, which we had happen to a fraser island tour bus, after about 6months of constant use the carrier bearings failed and damaged the LSD, it was'nt a unit we fitted so we had no idea of the installation, hence the reason we now offer free fitting for centres that are freighted us.
The main benefit of this type of LSD is the smooth transfer of drive which is beneficial in a front drive situation and no clutch packs to wear out.

Alan,
Thanks. These sure sound like the way to go, not only the way the torque is biased, but a lot of 'proving' with Fusos downunder. It is good to know about the carrier bearings, sounds like a good idea to replace those at the time of upgrading.

 

[fg4oz]

Hahaha!! Good on ya bloke. Hahaha.



Dont feel too bad. Everyone else with 19.5's had to do the same. I think the conditions on Fraser last Xmas were some of the worst I've experienced in 40 years. A few months of dry and all the extra traffic and the sand just turns to bottomless powder. How rough were the inland tracks!!! We're you up there around the 5 th or 6 th of Jan ? Did you hear about that Dodge Ram that got pushed straight out into the surf as he tried to cross Eli. I saw it on the tilt tray going back on the barge. Not pretty. Mostly Eli is only a couple of 100mm deep but that day it was over the bonnet of a lot of 4bys .

Hey john, yea we were there from 28december to 8jan and saw our fair share of crazy stuff. Stopped and caught up with Brad and saw his great little rig, loved the can crusher. Also passed the golden warrior a few times. We crossed the inland tracks almost every 2nd day and we're surprised how fast the tour buses get through. They said they were dropping down to around 25psi even on their tyres.
We would have been stuck without the air compressor you installed too. It came in very handy.

One morning we tried getting through early, first ones about and managed to get all the way to Eli Creek but with the king tide there was no way we could get through. Then another guy pulled up he went to walk it and would have been head high. We waited 2 hours and it was still over the bonnets of all the 4WDs. We waited a bit more. I was expecting to see more failures that morning.

 

[Amesz00]

So the general consensus with torsen diffs seems to be that they work great (long as a wheels not in the air), but can't take the strain of large tyres and/or high torque applications..
John / Alan what is you guys take on this, given both your diffs are made specifically for canter front ends.. ie obviously they are ok for 19.5s or similar that are ~36" tall, but how about the 41s on my truck?
Also Alan, how much difference does the spring pre-loading make in offroad operation? Will it lock with a wheel in the air (as I've witnessed with canter rear LSD), or just make the unit tighter with wheelspin?
Andrew.

 

[alan]

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.