Mechron Differential Vent

[yuccafarmer]

I've got about 25 hrs. on my Mechron and am very happy with it. The ride is great as it seems to handle the washboard roads around here better than either my car or pickup.

The only problem I've noted is with the differential vents. After driving about a half mile at speeds of about 15 mph, lube is seen in both the front and rear vent tubes (see photo of rear tube).

I suspect lube is being pumped to the vent by the ring gear. Fluid level is proper, filled to fill plug level.

In the photo, the High Fluid Level was where the fluid was when I went into the house to get the camera. All fluid drained back into the housing in a few minutes.

I think there may be a design problem with the vent fitting on the differential, either with the location or perhaps with the fitting itself. When I contacted my dealer, he discussed this with someone at Kioti. The end result was that I was sent a new tube and fitting (outer fitting at upper end of tube) that appeared to be identical to the original. No surprise, the new behaved the same as the old.

My concern is that fluid loss (none seen so far) could occur on long trips or if the vent tube is somehow damaged. This is an annoyance at this point but seems like an issue that should be addressed by Kioti.

 

[Hard Knocks]

You should email your photo and comments to your dealer and ask them to pass them on to Kioti technical. You might not see any action rite away but at least you will know that Kioti has been alerted to this annoyance.

 

[Dmace]

Once you had driven a few miles and everything was at normal operating temperature, did you check the fluid level again?
With fluid in the tube, what happens when you remove the fill plug?

 

[yuccafarmer]

Hard Knocks - All this info and photos were sent to dealer who said he passed it on to Kioti.

Dmace - I believe this is not an issue with fluid level as the fill level is correct. I believe that the vent design is such that the ring gear can pump liquid into the vent when rotating at higher speeds. This effect is not seen if speeds are low. I do not know the details of the interior of the differential housing, but I would think that a baffle to prevent direct fluid entry to the vent would probably cure this issue.

I am curious as to whether others have noticed this happening.

 

[Dmace]

I didn't ask what you "believe", I asked did you recheck the level after getting it up to normal temp. If you fill the differential when it's cold with cold fluid to the max and then go riding around for miles heating up the rear end then it will be OVER-FILLED which would push fluid out the vent tube. If "speeds are low" then it won't heat up the differential or the fluid as much.

People are so quick to blame manufacturers and engineers when they mis-use a product.

So, when the unit is warm and driven for a few miles and you remove the fill plug does fluid come out?

 

[yuccafarmer]

No.

As shown in the attached photo, the filler plug is located such that the fluid will fill only about one half the volume of the housing. The vent tube is located at the top of the housing. Thus it is impossible to heat the lube to a temperature where it expands into the vent tube. In order to do so, the voulme of the lube would need to increase by a factor of two.

This problem was noted after I saw what appeared to be leakage from the boot area. However, after a few drops were noted as shown in the photo, the "leak" stopped. Thus I concluded that the suspect boot was not leaking and that the "leakage" was lube external to the seal that seeped via capillary action into the gap between the boot and housing.

The furthest I've driven the machine in a single trip is about one mile. At the end of that drive (when the original photo posted above was taken), the housing was cool to the touch.

Again, this issue is seen on both the front and rear vent lines. I occurs whenever the machine is driven one half mile or more at speeds of 15 mph or more. It is not the result of over filling and is not the result of thermal expansion.

 

[MotorSeven]

If that much fluid is getting to the top of the pumpkin, I say it is overfilled(or filled with the wrong viscosity oil). I think the "full" level should be lower than the fill plug or drain and re-fill with a quality synthetic proper gear lube.

 

[somguyss]

I will step in and help you out on this I do know that Dasdong the parent company of KIOTI has made a change to the case cover of the differential for the front and rear. The problem is that the vent tube location is so close to the ring gears that when at high speeds for long periods of time it is carrying the fluid up the ring gears and out the vent tubes, this is a very commen issue with several other designs threw the years that UTV, ATV and auto makers have expierenced in the past. Like I said Daedong is aware of this issue and has made a change to the cover's I have had to have the covers replaced in the units that we have.

Front Diff Case Cover:

U3215-15301 (old)
U3215-15302 (new)

Rear Diff Case Cover:

U3215-13301 (old)
U3215-13302 (new)

New Breather and Hose:

U3215-16621 (breather)
U3215-16613 (hose)

 

[yuccafarmer]

somguyss - Thanks for the info. I do know the dealer said the Kioti person he talked with did ask about the serial number of the machine. It's likely I've got the old covers. Is there a an easy way to ID the old vs. new?

 

[somguyss]

According to your photo I can tell you that you have the old style, old style tube comes out of cover east/west new style comes out of cover north/south and you have the old style tube withte bolt in it where the new style actually has a little breather in it.
You do have the old style and you may want to send the dealer pictures of the the case covers so he can show it to KIOTI. The cover change will eliminat to issues that there are right now that it seems you are seeing both, it will fix the fluid rising in the tube of the vent and will stop oil sepage from the cv axle seals as well.