Hello,
is it here anybody owner of CFMOTO 820? Here in Slovenia me and my 4 coleagues we all have this ATV's, and all we have the same problems with differential. Differential is not working properlly and during driving sometimes bolcked (by me left) rear wheel (for second) and the result is moving the vehicel to left!!!!!!! Very dangerous! Like other result is worn out left rear rubber.
We find out that like factory mistake which is still not solved!
What are your experiences with?
IKE   

You found the problem? I have a Cforce 820le and i have the same problem

I have the same problem on my 820.
On top of all that, the oil light started flashing and I learned that the oil pressure really drops to zero sometimes and now I'm afraid the engine won't be damaged

Hi Greendot,

With regard to your oil problem see below: -

Your countries dealer and importer will have little or zero knowledge of this as their dealer support technical training network and technical bulletin reporting is potentially non-existent if it is the same as is here in the UK. CFMOTO and other quad bike manufactures do not have a full-blown HQ in UK and therefore after Sales support for customer, importer and dealer is practically non-existent. Therefore, here in the UK due to the lack of full After Sales support from the manufacturer dealers & importers concentrate selling quad bikes and quad bike parts. Most dealers here in UK are Garden Machinery providers for this type of quad bike, there are few that specialise in off road and on road quad bikes and the in-depth technicalities and requirements for this product. There are some professional & knowledgably quad bike dealers, but they deal exclusively with racing quad bikes only.

Oil light coming on under heavy braking and cornering CFMOTO C force 800 X8 Euro 4 spec This is a common problem on the V twin cylinder, liquid cooled, 4-stroke, SOHC, 8-valve,  800cc engine, more of a problem if you believe the engine dipstick indicated "Full Oil Level" position on the dipstick as produced and exited the CFMOTO factory.


If you follow the instruction in the CFMOTO manual the engine is filled with oil when at the top of the taper bit on the dip stick, (See attached image) well it might be but the oil light will come on under heavy braking and cornering. With extensive testing and different combinations in my experience fill the engine until the oil level is approx. 25% above the taper on the dipstick. I am not sure what this equates to in additional oil quantity or if indeed it matches the extra quantity of oil your dealers have recommended. This definitively worked for me, with zero issues of oil light coming on under heavy braking and cornering once filled as recommended above.

Enjoy your ride......Take care. Grandmaster Splash & His Furious Ride

Hello IKE,

I hope the information below is helpful to explain how your rear diff and auto diff lock works, I cannot be absolutely sure I am answering your question as I have not fully understood your question.

There is not a problem with your rear transmission.
Your countries dealer and importer will have little or zero knowledge of this as their dealer support technical training network is potentially non-existent if it is the same as is here in the UK. Here in the UK they do not have the time or inclination to begin to understand or want to understand.  Their only aim being to sell quad bike bikes and quad bike parts, the majority of dealers here in UK are Garden Machinery providers for this type of quad bike, there are few that specialise in off road and on road quad bikes and the in depth technicalities and requirements. There are some professional & knowledgably quad bike dealers, but they deal exclusively with racing quad bikes only.
Fitted to the rear axle of your model X8 I suspect is an Eaton Detroit Locker NoSpin Diff unit. Be sure to use a quality petroleum/mineral based oil, it works best in the Detroit Locker units. Something like a recommend synthetic oil, friction additive/modifier is not required, i.e. Comma EP 80W-90 GL-4 Mineral Gear Oil. I use Fuchs Gear Oil Silkolene Boa 80W-90 Mineral oil designed specifically for these axles. I change that oil in both axles every year irrespective of mileage and use as it will prolong axle life. You will get premature failure of the axles and diff units if you use the wrong lubrication. If you are putting your machine through hard off-road use change the oil every year or more often. Some dealers may refer to this a "Jaw" diff, only because that is what their parts systems tell them. The term "Jaw Diff" is not a Brand name it is a lose technical term derived from the fact that the planetary gears on each end of the half shafts have dog clutches on them. These dog clutches are a set of matching dog teeth on each end of the diff gears and half shaft gears. A dog clutch system has been used on incredibly old a basic manual gearbox for decades, the two sets of dog clutch gears on each side of the diff are loosely referred to as a "Jaws". Confusing yes, can the dealers and importers explain this no, I hope it helps and makes sense to you? 
In short what happens is this: -
•   Driving straight ahead on a tarmac road at high speed or low speed off road the diff is locked, i.e. the wheels will not turn at different speeds, they are locked as one solid drive same speed to both wheels.
•   When you turn a corner especially on tarmac the diff unlocks & permits the rear wheels to turn at different speeds like a normal diff. Especially the inside wheel of the corner as it has more traction/resistance and difficulty in turning. The increased torque on the inside wheel cause the spring to unlock the locked diff. Because you are on tarmac and turning slow you get a clunking type of noise from the rear diff area. This is normal, there are some hefty springs disengaging the planetary wheel of the diff unit to allow the wheel to turn at different speeds. The tyres are providing excellent grip and will not slip hence the diff gear mechanism clunks and clicks as the mechanism engages and disengages. The Clunk/click noise from the rear diff unit is more pronounced on tarmac road than loose ground surface. As you corner at slow speed on tarmac you may also notice/feel a kind of jerking or clunking from the rear wheels, its as if you have poor throttle control. However, it is the dog clutch gears engaging and disengaging as you corner, try as you might to control throttle it will always happen with this design diff. Decades ago the majority of manual gearboxes on cars and trucks had dog clutch gearboxes i.e. no synchromesh units on every gear. To prevent the gears from stripping their teeth every time a gear was selected one and to double clutch and rev the engine between gear. This process matched the speeds of the layshaft and main shaft in the gearbox prevent the gears from crunching when you changed gear. It is not possible to adopt a driving technique with the CFMOTO 800 X8 to prevent the clunk/click from the rear axle as the whole process is automated. Be aware of it keep the axles topped up with oil and change the oil more regular than recommended by CFMOTO.
•   The noise will be less pronounced on lose ground off road when cornering at low speed, the noise is not so noticeable on tarmac at high speed cornering but this as you know is not advised on quad bikes due to your high centre of gravity. 
I attach the Eaton manual for you, there is also a test/check sequence in the manual,  you will also find some videos on You tube if you want a more in-depth appreciation of how this works, please link to bespoke Eaton video on you tube below FYI. After watching the video hopefully all the pennies will drop it is fairly straight forward.

https://www.youtube.com/watch?v=AuZqG7pTabw

Enjoy your ride...............Stay Safe..............Grandmaster Splash & his Furious Ride