Mechanical Four Wheel Assist??

   / Mechanical Four Wheel Assist?? #1  

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Kioti CX2510 HST
   / Mechanical Four Wheel Assist?? #2  
The XG3135 that has my interest at the moment has a Mechanical Four Wheel Assist according to the LS website.

XG3135H-35HP | LS Tractor

Is there a difference between that and MFWD or is it all just -- Whatever -- Marketing, terminology, branding....??

I searched and found this --

https://www.tractorbynet.com/forums...isons/320278-difference-between-4wd-mfwd.html

But reading that just left me scratching my head.

Dandruff :confused3:


No difference, it's the same.
 
   / Mechanical Four Wheel Assist?? #3  
Most commonly there is - 2WD, 4WD & all wheel drive( full time 4WD, AWD ). There are multiple names for each of these systems. It's all in the way a company chooses to advertise their product. Likewise - there are multiple methods to activate/deactivate the 4WD & AWD systems. Likewise - there are multiple way to control the 4WD & AWD system. When you put the advertising design person together with the sales manager, the corporate management staff and the production engineer - you end up with some really strange concepts and language.
 
   / Mechanical Four Wheel Assist?? #4  
Most commonly there is - 2WD, 4WD & all wheel drive( full time 4WD, AWD ). There are multiple names for each of these systems. It's all in the way a company chooses to advertise their product. Likewise - there are multiple methods to activate/deactivate the 4WD & AWD systems. Likewise - there are multiple way to control the 4WD & AWD system. When you put the advertising design person together with the sales manager, the corporate management staff and the production engineer - you end up with some really strange concepts and language.

Tractors are either 4WD or FWA.

That's four wheel drive.

That's front wheel assist.

4WD tractors are traditionally used in broad acre farming. They are traditionally 150hp+. The key is that all wheels on a true 4WD tractor are the same diameter. These tractors are used in pulling rather than for their 3PL capability. In most instances these 4WD tractors run duals - that's 8 wheels in groups of two.

A tractor like you are looking at (and like I own) have a smaller diameter front wheel. The front wheels can be driven. These tractors with a smaller diameter front wheel are FWA - that's front wheel assist. The manual on my tractor states that I can engage the mechanical four wheel drive. The manual is incorrect. My tractor is front wheel assist. I have a smaller diameter front wheel than on the rear.

I may upset a few members here, but FWA is probably the most misused, as well as the most misunderstood technology. The easiest way to understand if the operator doesn't understand FWA, is to examine the front tyres of his FWA tractor. The front tyres will wear incredibly if the FWA has been improperly used.

FWA is fabulous for engine braking on steeper ground. It's also fabulous for pulling, and for thrusting a bucket into a pile of dirt.

Apart from that - it doesn't have to be engaged.

The smaller front wheels must rotate at the same speed as the larger rears when FWA is engaged. Consequently the front wheels will always scrub. That causes the excessive wear. I see so many operators who have 4WA engaged all of the time - even when on hard surfaces or on the road.

The wear that the transmission must cope with is incredible if FWA is engaged on a hard surface with the bucket of a FEL full. It's a real credit to the engineers who design these things.

The FWA controller is probably the most used item on my tractor.

FWA is fabulous. If you need it, then engage it. Otherwise don't have it engaged. My property is steep so I couldn't do without it. I would never, ever, ever have the fronts engaged whilst on a sealed road or a hard surface, and I would never engage the fronts after filling a bucket on my FEL.

Manufactures are tending to call FWA Four Wheel Assist. I guess I can live with this. It's still front wheel assist but what it isn't is four wheel drive.

There are front wheel assist tractors at the higher end of the market that can self-manage engaging the front wheels into drive mode. Sensors and computer technology manage the front wheel engagement if the rear wheels are sensed slipping. This changes nothing, as despite these tractors being over 100hp, the front wheels are still a smaller diameter than the rear wheels. It reinforces what I am saying - only engage the front wheels if required.

Our local tractor mechanic has repaired a multitude of the cheaper Chinese front wheel assist tractors. When the front wheel assist is mis-managed on these cheaper units, something breaks. I have seen broken planetary drives in the front wheels, broken drive shafts and twisted and broken transmission shafts. The best was a clutch that had completely failed on a cheaper branded tractor. The unit was purchased new and had done 8 hours.

Hope this helps.
 
Last edited:
   / Mechanical Four Wheel Assist?? #5  
Tractors are either 4WD or FWA.

That's four wheel drive.

That's front wheel assist.

4WD tractors are traditionally used in broad acre farming. They are traditionally 150hp+. The key is that all wheels on a true 4WD tractor are the same diameter. These tractors are used in pulling rather than for their 3PL capability. In most instances these 4WD tractors run duals - that's 8 wheels in groups of two.

A tractor like you are looking at (and like I own) have a smaller diameter front wheel. The front wheels can be driven. These tractors with a smaller diameter front wheel are FWA - that's front wheel assist. The manual on my tractor states that I can engage the mechanical four wheel drive. The manual is incorrect. My tractor is front wheel assist. I have a smaller diameter front wheel than on the rear.

I may upset a few members here, but FWA is probably the most misused, as well as the most misunderstood technology. The easiest way to understand if the operator doesn't understand FWA, is to examine the front tyres of his FWA tractor. The front tyres will wear incredibly if the FWA has been improperly used.

FWA is fabulous for engine braking on steeper ground. It's also fabulous for pulling, and for thrusting a bucket into a pile of dirt.

Apart from that - it doesn't have to be engaged.

The smaller front wheels must rotate at the same speed as the larger rears when FWA is engaged. Consequently the front wheels will always scrub. That causes the excessive wear. I see so many operators who have 4WA engaged all of the time - even when on hard surfaces or on the road.

The wear that the transmission must cope with is incredible if FWA is engaged on a hard surface with the bucket of a FEL full. It's a real credit to the engineers who design these things.

The FWA controller is probably the most used item on my tractor.

FWA is fabulous. If you need it, then engage it. Otherwise don't have it engaged. My property is steep so I couldn't do without it. I would never, ever, ever have the fronts engaged whilst on a sealed road or a hard surface, and I would never engage the fronts after filling a bucket on my FEL.

Manufactures are tending to call FWA Four Wheel Assist. I guess I can live with this. It's still front wheel assist but what it isn't is four wheel drive.

There are front wheel assist tractors at the higher end of the market that can self-manage engaging the front wheels into drive mode. Sensors and computer technology manage the front wheel engagement if the rear wheels are sensed slipping. This changes nothing, as despite these tractors being over 100hp, the front wheels are still a smaller diameter than the rear wheels. It reinforces what I am saying - only engage the front wheels if required.

Our local tractor mechanic has repaired a multitude of the cheaper Chinese front wheel assist tractors. When the front wheel assist is mis-managed on these cheaper units, something breaks. I have seen broken planetary drives in the front wheels, broken drive shafts and twisted and broken transmission shafts. The best was a clutch that had completely failed on a cheaper branded tractor. The unit was purchased new and had done 8 hours.

Hope this helps.
Not entirely accurate, on most tradition tractors with 4wd or FWA (both terms are accurate) the axles do not turn the same rpm with dissimilar sized tires, the scrubbing you experience is a small amount of lead (the front tires turning slightly faster then necessary to maintain a matching ratio) typically around 10% to aid in steering. The size difference of the tires has no bearing on on drive type, only the final drive ratios.

As to the OP question, its marketing, there are some hydraulic assist axles on the market so I guess the wanted to include the mechanical in the description, but if full power can be supplied to all 4 wheels, its 4wd.
 
   / Mechanical Four Wheel Assist??
  • Thread Starter
#6  
So, IOW, it's a technicality I don't need to concern myself with?

Good stuff. All of you

Thanks
 
   / Mechanical Four Wheel Assist?? #7  
Not entirely accurate, on most tradition tractors with 4wd or FWA (both terms are accurate) the axles do not turn the same rpm with dissimilar sized tires, the scrubbing you experience is a small amount of lead (the front tires turning slightly faster then necessary to maintain a matching ratio) typically around 10% to aid in steering. The size difference of the tires has no bearing on on drive type, only the final drive ratios.

As to the OP question, its marketing, there are some hydraulic assist axles on the market so I guess the wanted to include the mechanical in the description, but if full power can be supplied to all 4 wheels, its 4wd.

There are 100,000 posts/threads and articles regarding 4WD vs FWA and what constitutes either.

It is best summed up by this quote from another post:-

"Nontheless, 4WD is a term that men will fight about for all eternity and really women have a good reason to laugh at for this.

Again there is a massive need for an engineering group to properly define the terms."
 
   / Mechanical Four Wheel Assist?? #8  
Grand L owner's manual calls it 4WD consistently across the book which is good enough for me.

From the car world 4wd is for off-road and non-paved surfaces only due to lack of a differential in both the front axle and front/back drive shaft. Awd is for systems that can cleanly handle different speeds for rotation across all 4 tires while still supplying power to all wheels and safe to use 100% of the time.
 
   / Mechanical Four Wheel Assist?? #9  
Grand L owner's manual calls it 4WD consistently across the book which is good enough for me.

From the car world 4wd is for off-road and non-paved surfaces only due to lack of a differential in both the front axle and front/back drive shaft. Awd is for systems that can cleanly handle different speeds for rotation across all 4 tires while still supplying power to all wheels and safe to use 100% of the time.

We can go on and on forever.....
"From the car world" are there any 4WD cars out there that have different diameter front wheels to the rears?

The importance for me is how the FWA ability of tractors is used. So call it 4WD on your Kubota and lets move on.

FWA is fabulous. I engage it when I need it, and use 2WD when I don't. As long as tractor owners understand that if your smaller diameter front wheels are engaged when they don't have to be, you are placing incredible strain on the transmission and drive shafts.

What suffers are the front tyres, so whilst your rears will be in great condition your fronts will suffer much more wear.
 
   / Mechanical Four Wheel Assist?? #10  
Tire diameter doesn't matter, only the ability to handle different speeds across the tires.

For what it's worth our car drives the front wheels slightly faster than the rears(same as you see in 4WD S/CUT) the difference is that system has the ability to measure resistance and back off, uses an open differential to keep the wheels from binding and doesn't have a driveshaft connecting the front and rear axles.

S/CUTs do the same thing, they run the front slightly faster to help with steering. They also have the advantage of running off paved roads + having more robust transmissions, running any system like that(car, tractor or truck) on paved roads without some sort of a differential is obviously not a bright idea.
 

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