I have a 1987 warrior that is leaking oil behind the output sproket. I took the sproket off it looks like the oil is coming out between the collar and the splined shaft. Do I need to replace the o ring behind the collar. Will the collar come off without splitting the case thanks for any help

 

How bad of a leak is it? If it is just a seep I wouldn't be too concerned about it, but if it is affecting your oil level, that is a different story.

 

even if it is just a seep i would change it anyway because it will only get worse over time. as far as the shaft goes you do have to split the case to remove the shaft i believe. i have an 87 warrior 350 also but i never had that problem.

like i said it will get worse over time so i would change it anyway before it does get worse. but that's just me