Clunk Clunk From Chaincase

snowhite

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Joined
Mar 18, 2008
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181
Age
62
Location
Flin Flon,Manitoba
Hello everyone. I am at witts end with this sed.KABOOMM is what i'd really like to do. So here is my delima, long story shortened;the sled has a clunk clunk in the drive(chaincase)I thought I fried a belt because the sled got stuck and of course it'll flatten,thats what it sounds like when I creep the sled very slow changed to a new belt. Did a bearing change in the chaincase top one was done, put on a new chain,checked every bearing on the sprockets and reverse gears inside alls good.Now this clunking is in the chaincase becuse while driving I moved the rev.lever and it changed sound.The adjustment procedure for rev. models on tech page is goofey because the way it is written. Everything is put togethar to spec. The clunking isn't there when the sled speeds it's just at the point where it's going very slow.I don't understand whats up with this, anyone have this occur at one time?
 

no..it is his venture 600..rev means reverse in his words..Kapusta..tough times for you..wish you could solve it..somethings is loose or not lined up correctly or broken.If there is a clunk sound..something is not right somewhere..you'll have to open up the chaincase again and explore...I don't have a clue about the reverse in them sleds..someone else will have to chime in here to help ya..
 
go for a slow ride to replicate the clunking noise, then grab the brake lever and keep pressure on it so pads are squeezing the brake rotor slightly but not completely stopping it from turning... does the clunk go away/diminish?...

also.. was the alternate drive belt brand spanking new from the dealer (used for the very first time) or was it ever used before?


I have a similar clunk on both my sleds (each has reverse)... there are 3 things that I have found to contribute to it: 1) the brake rotor is slightly loose on the jackshaft and the key is not keeping it perfectly snug... this causes vibration of the rotor producing a clunk at slow speeds... 2) my secondary clutch is shimmed on the jackshaft to float a few thou (when you push and pull my secondary, there is some end free play). This free play actually allows the secondary to walk back and forth on the shaft at slow speeds, producing a terrible clunk... 3) an old/used/bad belt will amplify the first two issues 10 fold... A new belt helps considerably but does not eliminate the issue 100%...

Try shimming your secondary snug just briefly to test the free play issue... Not suggesting you leave it shimmed snug since my sled shifts and backshift better with a floating secondary... tj..
 
Hello guys',yes REV. is short for reverse.Now the belt is brand new actually I tried my two old ones which always worked fine.The clunking is why I changed my belt originally after I got stuck,this is why I went into the chaincase to see what went wrong in there.Put new bearings/seals,new chain,gears all looked o.k(some wear on reverse gears)Went for a ride and yes I tried the brake thing because that brake disc is loose on the jack didn't change the clunk.So I moved the reverse handle and the noise changed! So this lead me back the chaincase. In the tech section it describes how to adjust the rods for the reverse models tried all this and still have the klunk,only when the sled is creeping very slowlly.Everything I could think to check,watched under the sled while running the track nothing bent or siezed.The klunk isn't there when I have the sled jacked up so its very confusing.But today is nice and SUNNY and warm (damm the weather) i'll be going back into it to see how crazy a guy can really get over a sled.I'll post you guys what shape I am in later.....hehe..beeeeerrrr.
 
Did you check your skid lately? Warn bushings could cause this also. Just tore my daughters viper down to the last bolt for a low speed clunck and best i cam come up with is it was a worn skid. Bushings were gone and shaft was wore dont at least 1/8 if not more. Im guesing it was moving at slow speeds. Cant tell till you get the skid out if its loose. Chris
 
:dunno: Well I said I'd be back like Arnie swatzenger.Took case apart to see if everything was in order as it was(parts),now put 'er all togethar and went for a ride she's smooth as silk cruising but she still has a bit of a klunk going very slow.So like TJ500 said there is a klunking on the reverse models just seems that for 8,500 kms. I put on her I never noticed it.So maybe I just gotta keep down on the handlebar.There is always wear and play on all moving parts its' logic.And no I didn't even have a BEER for all this.Thanks guys for the help again and now I'm going ice fishing.....
 
check the plastic ramps in the secondary. i forget what they call them. (3) total. had the same problem at low speeds & once you get going it's fine. bought it this way & rode it until i said enough, time to fix it. ended up pulling the secondary off & apart. i only had 1 plastic shoe in, the other 2 were gone. put in 3 new ones, problem fixed.
this was on a 94 vmax w/ rev.

just a thought it may be your issue too.
 
I am betting the bushings in the skid are gone and that you have a bent or broken W-arm. Pull the skid, take it apart, clean it up and then follow Behtevipers rear suspension setup instructions when you put it all back together.
 
Mills said:
I am betting the bushings in the skid are gone and that you have a bent or broken W-arm. Pull the skid, take it apart, clean it up and then follow Behtevipers rear suspension setup instructions when you put it all back together.

not for a moment disputing your suggestion as I may even go through my skids again too... but, how exactly does a worn skid contribute to this clunking noise... just can't get my head around it.. thanks...
 
simply if something is broke or bent..clunk sound..sound of something that is starting to fly apart.I had a weird noise coming from my 600 years back,drove me nuts...then finally while checking things over..discovered my front exchanger protector on the left side broke loose on the bottom,still being held by the top end..but it was making a sound that drove me crazy.It was bouncing off the track at higher speeds.lucky I found it..could of totally let go and jammed up the track and/or destroyed my exchanger..
 
TJ500 said:
not for a moment disputing your suggestion as I may even go through my skids again too... but, how exactly does a worn skid contribute to this clunking noise... just can't get my head around it.. thanks...


Not to speak for Mills but I'd guess worn bushings, broken w-arm, broken w-arm mount at the rail, broken shock mount, etc... can cause misalignment of the skid and or track which will have things contacting things that shouldn't be contacting each other. Having reverse would only add to the movement of worn parts.

Just a guess.
 
At slow speeds with worn bushings the suspension can "walk around" on the mounting shafts as it transitions through its travel as you cross humps and bumps. At higher speeds you may still be getting the same sounds but you aren't able to hear them or the suspension is pulled tight against the mounting shaft with the higer friction load from the track.
The W-arm is a good place to start looking. Mine was broken but I couldn't see it until I took the suspension out. Even if it is not broken it would be a good idea to take it out and have it reinforced so that it doesn't happen in the future. The W-arm in the Proaction suspension is the weak link unless you get it reinforced.
 


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