09 Kodiak 350 rear differential seals blew

[kinleyg]

Hi,

I'm new to the board and am pretty new to ATV's in general, I do have a decent amount of car knowledge but my ATV knowledge is very limited. So onto my question.

We recently bought 2 ATV's an 09 Yamaha Kodiak 350 and an arctic cat 500. The Kodiak has about 200km on it and it went in for a service. After we got it back we went out riding for 15 or 20km and then on the way back all of a sudden a giant cloud of black smoke was coming out of the back end. Smelled like burning oil and the ATV lost power greatly. Got it back to the house and looked under it and it looked like there was oil coming from the rear dif.

So we proceeded to load it on the truck and take it back to the dealer where it was serviced. Got a call from them saying that the seals on the dif had blown and replacement parts would be about $20 and then it would be about 1 hour of labor to fix it, so we said alright but ask how it could have happened.

They call back saying that the problem was caused by whoever was riding had kept the rear brake on for the entire ride and because of that it had caused heat in the rear dif which then caused the oil to basically boil and blow the seals on the dif but also caused $700 in damage to the dif and parts around it.

So after my long winded explanation my question is, is this actually possible? Could the rear break being on cause all this damage? Next question is, could they have done something wrong during the service to cause the problem? Lastly I know that my wife didn't have the brake on while she was riding it and I was on mine behind her and I know the brake lights weren't on so is there a way that the brakes were on without being pushed and the brake light not being lit up?

Thanks so much for any help on this matter.

[Delbert]

Don't know if you have DISC or DRUM brakes, but YES, by being applied for long periods of time they possibly can boil the fluids near the source and rupture seals without the brake light being on, and all the differential fluid would leak out, which would overheat the differential once enough fluid leaked out. It's the "old snowball effect". Here's how. When you bought the ATV the Service department(upon assembly/inspection/) misadjusted the brakes(drum) too tight with the brake rod and it essentially kept the brake dragging in the housing without you knowing it. If you have a DISC brake setup, the only way this will happen is if the brake caliper had some rust buildup on the disc piston(s) and the pads hungup and started dragging as if, you had your foot on the brake pedal. Another possibility would be a faulty brake switch. All these possibilities WOULD NOT set off the brake lamp. I know this is probably covered under warranty, but ask the Service Manager this question once you get back your ATV and the run down of what parts were replaced if you don't see them on the repair order. If the brake pads(disc) or shoes(drum) had been on and boiled the differential fluid---where's ALL THE NEW BRAKE COMPONENTS that needed to be replaced due to warpage of disc rotor, pads and replacement of disc caliper and all hardware, OR, if drum brakes--replacement of drum, brake shoes and all it's hardware? This would also include brake fluid. Also, there should be a new brake switch on the repair order if it also was at fault--or as I said earlier, possibly a misadjusted brake rod(if it has one) then the brake switch would be good. Don't let the Dealership get away with telling you one thing and replacing something else that had no part in your ATV going back to them for warranty work. If it was the brakes that caused all these problems--- then brake parts will be on the repair order. If not---see the shop manager. Good luck
Delbert