Clunking when off throttle

[JESSE BRANCO]

Hey everybody.
When out for a ride yesterday I noticed a really loud CLUNK CLUNK CLUNK noise everytime I let off the throttle. This noise would continue until I came to a dead stop. The clunk intervals do get slower as the machine slows. As soon as you touch the throttle the noise seems to go away. I checked chain and track tension, drive bearings look ok, nothing stuck up in the tunnel. It almost sounds like the secondary clutch banging around from side to side like these do but its to consistent of a noise. Any idea?

 

[allyammies]

Sure it is not the transfer rod clunking. My apex would do this.

 

[JESSE BRANCO]

Sure it is not the transfer rod clunking. My apex would do this.

I thought so at first but it does it even on the smooth snow. Its as soon as you let off the throttle it will clunk all the way to a dead stop. Could it be the cogs slipping? Track tension checks out and there is no noticeable ratcheting on take off :S...
It really does sound like the cutch banging from side to side just a lot louder then normal.

 

[JESSE BRANCO]

Something else I just thought of is earlier in the day I got it stuck and burnt the belt a little. Would a "divot" in the belt throw it off enough to slap the clutch around like that?

 

[allyammies]

If a cog is out of belt it will make a noise too.

 

[RAMSOMAIR]

You betcha! I would look for that first.

 

[JESSE BRANCO]

Urgh! I should of thought of this yesterday on the trail and swapped out belt to test. Im going to go pull the belt now and inspect. Thanks guys!!

 

[Dominic lachance]

Hey I’m having the same issue with my sled, pulled chain case completely apart noting is wrong in there, put on a fresh belt, same noise clutches are clean, but the one thing I did notice is that my dads old rx1 and vector make a somewhat of a winding down sound when you let off of the throttle mine make a somewhat clunking/ grinding sound, runs fine all the other time except when I’m off the throttle can get right back on the throttle and it’s fine it’s making the sound only when the engine is breaking

 

[74Nitro]

My Nytro always had the clunk when slowing and braking from the chaincase reverse gear going from unloaded to loaded.
However your noise may be something different Jesse.

 

[74Nitro]

I would think if the belt is bad it will also do while accelerating.

 

[maim]

burnt belt will clunk all the time. clunking on deceleration is usually the slack built in for reverse gear and being on and off of the throttle. my old rx war has been clunking like that for 18000 km at least. 11 apex is 27000 km like that.

 

[sxr70001]

Could be the driveshaft bearing too. You want to check that before it eats you speedometer sensor.

 

[JESSE BRANCO]

Well changed the belt and it helped for sure but not gone. I dont really have snow to test it properly but hopefully this weekend! Good to know everybody has a clunk though lol

 

[RX-1MAN]

Make sure the bearing lock nut on left side of secondary shaft didn't come loose. Mine did years ago and it would bounce around the shaft as the sled was moving. I could feel it in the left footwell and hear it.

 

[03RX1-ER-LE]

Check Jackshaft and Driveshaft bearings closely, sounds like one of them.
Bad belt clunks all the time like Maim said.
Let off throttle and one clunk seems like the norm along with whine on decel which is the norm.
Clunk on decel the whole time slowing down, jack/driveshaft bearing.