All Wheel Drive ?

[Grant Bowker]

Going back to the M135, all of the SAE terms:
On-Demand Synchro Variable Torque Passive System
On-Demand Synchro Variable Torque Active System
On-Demand Independently Powered Variable Torque Active System
seem awfully fancy compared to a system that was of the same vintage as the early LandRover described above (only slightly fancier in being linked to the reverse shift position, the truck had an automatic transmission as well to simplify driving). The variable torque of the M135 is basically binary, either engaged or not.
It would seem that the SAE J1952 standard was first published 1991,(well after the M135 and LandRover were designed) https://www.sae.org/standards/content/j1952_199101/ and to be a bit picky is only intended to apply to light trucks up to class 3 which seems to top out at 14000 pounds GVW. https://en.wikipedia.org/wiki/Truck_classification It isn't clear if this is the same class 3 definition SAE is using.
I could facetiously claim the 4wd system on my F350 is also "on demand" - when I demand power to the front wheels by moving the floor mounted shift lever, power is delivered.

I wasn't trying to tell anyone they were wrong, only to suggest that are a large variety of systems that can't all be neatly pigeon holed.

[Lang]

Grant

I was not suggesting you are wrong just that the SAE main descriptions are general names for the only three possibilities to achieve all wheel drive. Even then one could argue "on demand" is really a part time system. How they are arrived at is only limited by the imagination of the engineers and how complicated and expensive the manufacturers are willing to pursue development of the weird and wonderful.

I think the 3 general descriptions (part time, full time and on-demand) cover everything possible but the sub-list of methods and designs to achieve one of those 3 results will go on expanding forever.

It is still hard to pigeon hole a design. What about a vehicle that normally runs 90% rear and 10% front - got to be full time. But if it has sensors that detect rear wheel slip and feeds power to the front axle until there is a 50/50 sharing it has got to be on demand? And if you can turn the four wheel drive off completely it has to be part time?

Lang

[Lang]

Mike K

Thanks for the Landrover info.

Lang

[Mike Cecil]

Just love these wandering discussions .... just like asking 'what hat do we wear on ANZAC Day?' at a VMVC meeting!

Very interesting stuff, guys. I figured the collective wisdom would provide a veritable bounty on interesting replies: thank you all.

Mike

[Ken Smith]

Don't forget International called their 4 x 4 trucks, including our own teaspoon tippers All Wheel Drive. They had a nice little badge on both mudguards/fenders.
The badge was on AA series and the AB series as far as I know, and the same badge was used on the four cylinder Scouts from the early sixties.
Ken

[Hanno Spoelstra]

A lot is written about this subject already, but I’d like to add that Marmon-Herrington’s core business, since 1931, is the design and production of All-Wheel Drive conversion kits (they built complete vehicles, even tanks, as well).

“All-Wheel Drive” was incorporated in their old logo, and the term was actively marketed by them.

3B45BAFF-A8F5-4438-8E7D-B1983A13F855.gif

Maybe they had it trademarked or patented? That is what I would have to look into. For now, I leave you with a link to my old M-H website:

http://www.mapleleafup.nl/marmonherrington/

HTH,
Hanno


18E3A37F-472E-4172-AA17-59FD5FF6EB23.jpeg 5B77C3D2-B2CA-4D70-BC2C-DE5962D6632A.jpeg 6F2B1A12-6E44-493E-8DB6-1EC5B0A3E7B2.jpeg

1A6B2E73-D16C-4733-A7F8-52DAE55FDE7B.jpeg

[Lang]

Here is an interesting Quad story.

http://archive.commercialmotor.com/a...ment-for-mules

[Lang]

Hanno

I doubt very much if MH could have patented the expression "All Wheel Drive" as it had been in common use for half a century. They certainly could have patented their badge but not the stand alone words.

Everybody was doing it.

The all-wheel-drive history of Daimler AG begins in 1903
Commercial vehicles are the main beneficiaries of all-wheel drive
Experience with the first four-wheel drive commercial vehicles lead to the ‘Dernburg-Wagen’ in 1907
The all-wheel-drive history of Daimler AG began around the turn of the century. During his time as Technical Manager of the Austrian Daimler-Motoren-Gesellschaft in Vienna-Neustadt, Paul Daimler had already ‘produced the basis of a four-wheel-drive design in 1903,’ as the publication Illustrierte Zeitung reported in issue 3846 in 1917. As is often the case with technical developments, it was the military that provided the initial impetus. The first such vehicle to be designed was an all-wheel drive armoured reconnaissance vehicle, which was tested successfully in 1905 before being delivered to the Austrian army. Powered by an 8.5-litre, four-cylinder engine developing 50 hp (37 kW) at 1000 rpm, it had a ground clearance of 335 millimetres and an indicated climbing ability of 18 per cent.
1905/06 saw production of armoured vehicles with all-wheel drive. ‘The vehicles were equipped with a 30 hp engine, and as trials demonstrated, these were capable of overcoming considerable gradients, even over rough ground and when fully laden,’ wrote the Illustrierte Zeitung. ‘ They are also capable of moving at considerable speed over different types of terrain.’ In addition to four-wheel drive, the vehicles were fitted with a cable winch to haul themselves over obstacles.
After these first vehicles, the Prussian army purchased two all-wheel-drive trucks from DMG for suitability trials in 1907. These were powered by a model F 6 six-cylinder engine developing 70 hp (51 kW) at 820 rpm from a displacement of 12.7 litres. These vehicles particularly proved their worth in comparison with rear-wheel-drive equivalents during a Berlin–Glatz–Berlin test run, and reports show that gradients or unfavourable road surfaces presented no problem. The claimed climbing ability was 25 per cent unladen and 12 per cent with two trailers. The iron wheels (with wooden spokes) tended to distort after prolonged use, however. Despite these predominantly positive results these early all-wheel-drive vehicles did not remain with the military, probably because the amy authorities were still wedded to horse-drawn wagons; the two trucks were sold to Krupp AG. But in subsequent years all-wheel-drive vehicles for special purposes became gradually established with the military in the form of tractor units, dropsiders or ambulances.
On the basis of this know-how, DMG built the ‘Dernburg’ in 1907, an all-wheel-drive car with all-wheel steering. Commercial vehicles with four driven wheels were also produced for use in the colonies. There was a tractor unit destined for Portuguese South Africa in 1908, for example, which possessed an extremely good climbing ability of 45 per cent when unladen, and still managed 20 per cent when laden.