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It seems that all SXS manufactures have had their troubles making a differential that will hold up to the kind of abuse that we subject them to. So far the YXZ differential seems to be holding up well. If Yamaha were to make an all around version of the YXZ with reduced gear ratios and a high low range then I can see how this may change. These modifications would increase the amount of torque going to the differentials by a large factor.
What to do? what to do/
A bigger ring and pinion, bigger bearings and a super strong housing, able to accept bigger stronger axles and of course hubs with a bigger bolt circle.
I think hydraulic actuated cone clutches. One to engage the four wheel drive located between the trans and the front drive shaft. The other on the differential to lock the front. Possibly a third in the rear to provide a turf mode. These would run off of a small electric hydraulic pump located under the dash.
Cone clutches are strong simple don't slip (unless designed to) and almost never wear out.
Next remove the over ride clutches and replace them with a simple passive device that's been in use for many years in the automotive industry. Its a drive shaft with a rubber shock cushion sandwiched in between its inner and outer diameter.
No it probably wouldn't be possible to retrofit this mod into the current frame.

Costs? Who Knows?
What are your thoughts?
 

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While I am all for upgrading, and even have a few ideas, let's not count the stock rear differential out until the limits are found. With the nose of the pinion supported by a bearing, like a Ford 9", and a load bolt for the ring gear, it should be able to take some abuse. The front diff is similar, but no load bolt. So what we need is someone to gear the trans down and put some big mudders on there.... and go at it.
 

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While I am all for upgrading, and even have a few ideas, let's not count the stock rear differential out until the limits are found. With the nose of the pinion supported by a bearing, like a Ford 9", and a load bolt for the ring gear, it should be able to take some abuse. The front diff is similar, but no load bolt. So what we need is someone to gear the trans down and put some big mudders on there.... and go at it.

There is already a complete new set of lower tranny gears available.
 

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I am betting the front diff can't take a whole lot.
The diffs are protected by a clutch mechanism in the transmission that keeps them from getting damaged when you land from a jump. They will probably do the same from big tires and lower trams gears.
 

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Tubeworks is now taking pre-orders for our brand new reduced ratio gear package, for the newly released Yamaha YXZ 1000-R divorced transmissions. Along with performing substantial lubrication modifications for the wet clutching system while the trans is apart, we are able to achieve an appropriate 30% ratio reduction across the board, along with an optional 70% reduction in 1st gear (for that desperately needed launch/crawling range set.) This drastically reduces the loads on the clutch system increasing the life expectancy, even with the use of larger tires. The new ratio set places 2nd gear very near to the original 1st gear ratio. 5th gear calcs out @ 10k RPM to near 70 mph speed with stock tire instead of almost 90mph, near 80 mph with 31" tire. This instantly puts 30% more torque to the tire in all gear ranges.


They also offer other options as just a straight 40% gear reduction for 1st only.
 

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The diffs are protected by a clutch mechanism in the transmission that keeps them from getting damaged when you land from a jump. They will probably do the same from big tires and lower trams gears.
The Front Diff is protected only with a clutch pack that filters the power or spike loads going to the front differential. It is located at the front output shaft where it leaves the transmission.

If larger tires, more traction, or more torque is generated at the front diff through lower gearing, the clutch pack will slip allowing no power to reach the front diff. This clutch pack is tuned for the current size of stock tires, and stock gearing.

As soon as everyone starts changing the gearing, tire size, trans ratio's and etc, this clutch pack will slip easier and basically be a 2WD or RWD only. This will also have to be modified to work with larger tires and lower gearing - Guaran Dam Teed!
 

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The Front Diff is protected only with a clutch pack that filters the power or spike loads going to the front differential. It is located at the front output shaft where it leaves the transmission.

If larger tires, more traction, or more torque is generated at the front diff through lower gearing, the clutch pack will slip allowing no power to reach the front diff. This clutch pack is tuned for the current size of stock tires, and stock gearing.

As soon as everyone starts changing the gearing, tire size, trans ratio's and etc, this clutch pack will slip easier and basically be a 2WD or RWD only. This will also have to be modified to work with larger tires and lower gearing - Guaran Dam Teed!
I'm having zero issues with my 30" ultra heavy Tensors.......
 

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Ok drifter since you Guarantee it won't work as is. What's the torque limit of the clutch pack? 500ft/lb, 1000 ft/lb, 10,000 ft/lb Also, since it's a clutch it'll slip but still grip at the same load rating. Not ever easier than it's load rating. It's probably damn high since it's made to slip on spike loads that'll snap axles and break diff's.
 

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I'm having zero issues with my 30" ultra heavy Tensors.......
Have you changed Trans gearing or Diff gears on anything yet? The way it sits now with heavier tires, your clutch in the transmission is the weak link or fuse that is!

Now add lower gearing, larger tires and extreme obstacles, and more torque applied to the front diff and it will slip easier.
 

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Ok drifter since you Guarantee it won't work as is. What's the torque limit of the clutch pack? 500ft/lb, 1000 ft/lb, 10,000 ft/lb Also, since it's a clutch it'll slip but still grip at the same load rating. Not ever easier than it's load rating. It's probably damn high since it's made to slip on spike loads that'll snap axles and break diff's.
Don't know the torque limit, and hopefully it's fairly high, but it will slip when more torque reaches the Front Diff. Changing the Trans gearing, or Input Shafts, or Diff gears, or all of the above then adding larger tires will definitely change the parameters of what it was designed for and it will slip!

Ever been stuck in a Car or Truck in Snow, Mud, or Ice with a limited slip differential? It's exactly the same principal and device on the YXZ. If the torque needed to drive the wheel with traction exceeds the limit of the clutch packs, power will go to the wheel with the least resistance so one wheel will spin without the other!!!

Ever been off roading in a Jeep or something without lockers? Put it in a situation where all the torque must go to just one wheel or one end and only just a clutch pack or limited slip = no go. Ever seen a Rock Crawler Jeep, Toy, or Buggy with a clutch pack monitoring power to the front diff? It would never work.

The only way to have 100% traction to all 4 Wheels is with it locked - no clutch packs. Unfortunately stuff breaks this way, but with a decent driver the benefits always out way the negatives.

It's no different than the the SLD (Spike Load Dampener) that Arctic Cat put on the back diffs of the Wildcats. Once torque exceeded the SLD it slipped and was front wheel drive only. It would recover after slipping, but would slip easier and easier the next time!!!

The only reason the Stock YXZ has not had any issues with this is because it is all designed and tuned around the stock setup, meaning the stock light weight tires, stock tall gearing, and stock transmission clutch pack.

Nobody has exceeded this yet, because its not able to be used this way as it is from the factory, gearing too high, Trans clutch slips - end of story!
 

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Nope and don't intend too, the machine is fine, now start adding turbos and race tunes then we 'may' need to be concerned. Many of us are running 30" with no issues.
That's cool and exactly what I'm saying! Your transmission Clutch pack is your fuse so really nothing is different as far as torque reaching the front diff. Change the gearing, gears, or etc and get into some real crawling and let me know?

The MPI Turbo car I've spent some fun times driving was great in 1st, 2nd, and 3rd, but would slip the stock clutch in 4th and 5th. It had less than 200 miles on it and this was only dune running with stock tires & wheels.
 

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That's cool and exactly what I'm saying! Your transmission Clutch pack is your fuse so really nothing is different as far as torque reaching the front diff. Change the gearing, gears, or etc and get into some real crawling and let me know?

The MPI Turbo car I've spent some fun times driving was great in 1st, 2nd, and 3rd, but would slip the stock clutch in 4th and 5th. It had less than 200 miles on it and this was only dune running with stock tires & wheels.
That's not what you said though, you said larger tires would cause slipping. I do not find this true. And the YXZ is NOT a rock crawler, wrong tool for the job. All you guys trying to make them work are paying the price or will IMO. (this is not personally directed at you but I'm tired of hearing the crawler cry)
 

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That's not what you said though, you said larger tires would cause slipping. I do not find this true. And the YXZ is NOT a rock crawler, wrong tool for the job. All you guys trying to make them work are paying the price or will IMO. (this is not personally directed at you but I'm tired of hearing the crawler cry)
I guess my question is how do you know it is not already slipping sometimes with the Tensors?

Each time it slips it will slip easier the next time.

I am sure they have it set fairly high, the YXZ on Boat Ramp was able to break a drivers side front axle so the protection wasn't there for that.

That front diff screams "ATV" and it is hard to believe it will ever survive in situations where there are big tires and lotsa on/off/on/off traction with lots of throttle and wheelspin scenarios.

It can be said (and probably will be) that they didn't build it for that but I have yet to see anywhere where Yamaha says it isn't built for any particular terrain or duty, only people asserting what they think it is meant for. If someone could point me to where Yamaha says it is not for mud or rocks or woods I would appreciate it. All other sport SxS's are all terrain capable.
 
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