hey 698...if there is a clunking sound,something may be broke.Your gonna have to inspect it.Put sled up on a stand and spin the track and see if it happens and keep your eyes and ears open.I had a strange sound from mine when I pinned it in deep snow,not very sure what it sounds like when racheting occurs,but didn't sound normal and kept bugging me.Today I spent a lot of time,defrosted the whole sled,checked everyhing over on the skid and tightened track bolts up 2.5 turns which gives me about 1" sag at 20 lbs pull.Track still rotates slighty when up on the stand(creeping a little),so I am happy with that.If you are to loose,maybe track is balooning and smacking something.
Check your w-arm for sure,because when I bought my SRX a few season's ago,my w-arm was almost toast.Lucky I spotted it early enough to save on a major problem it that arm would of twisted right up under acceleration.I have 4 w-arms in total.One on the SRX and SXR are re-welded and re-inforced.Also carry a spare for both also re-inforced.