keep snapping shafts on my 90 max

[pumacorp]

Anybody know if theres a bad batch of shafts out there??
I keep snapping them..Ive gone through 2 in the last 2 months and it doesnt make sense cause I live in NY where it is cold and there isnt any grip in the road
,,,yes im doing holeshots,,not a ton and yes I do wheelies,,,But I cant see a reason for this to happen...

It has a stage one with K&N chopped box and correctors.Also kerker headers with a 2 and 3/4 carbon fiber muffler that I custom fit cause the kerker muffler bogged me down..,..Bike does run away from stock maxes and pulls the wheel in second so its a peppy max...I just got done putting in my stage 7 and took out the vboost so this bike should be nasty,,but b4 I break another shaft I was hoping someone has answers to why im busting them..

And yes I know how to do hole shots lol...http://www.vmaxforum.net/images/icons/icon10.gif

 

[maxout1200]

I'm not aware of a problem. I have run a 85 and 93 vmax with Kirkers, stage 7, with the vboost eliminators and have never had problems with the drive shaft. Is your rear wheel turning freely? Are you a big guy?

 

[hubeerjw]

I guessing you may have a tranny problem. Might want to pull your secondary gear box cover off and see if there is a bad bearing near the u-joint on the engine cases. Just an idea, but if it is binding up somehow it may be creating a lot more stress on the shaft. Morley may have a little more insight on this.

 

[one2dmax]

You didn't say what you have for a clutch setup or rear wheel/tire combo.

Sean

 

[Jayhawk]

Just here to remind Danny that if he snaps his shaft, it might be due to a bad tranny. :rofl_200:

 

[82ndCowboy]

Are you always in the same gear when you snap a shaft?
My guess would be maybe for your weight your in too high of a gear when you getting on the throttle.

Of course it's just a GUESS.

 

[pumacorp]

Both times from a dead stop barely any real stress...The last one snapped like a joke with hardly any pressure maybe a 1/4 clutch with the bike just start moving it snapped..There has to be something putting lots of pressure on it I guess..

I have the DD clutch set up..I did it right ,,Ive changed 100s of clutches since my 1st bike 30 yrs ago lol...This actually was an easy one to do...
Stock rim and tire(of course who doesnt like the Dunlop smoker lol)
few solid mounts(I got lazy and didnt finish the mounts lol...)
It happened with stage 1 and stage 7...
Im no heavy weight im 200lbs....
Still scratching your heads???
I do however have a bit of drag on the clutch going into 2nd..I figured the DD
puts more grab cause of the extra full friction and extra spring...

 

[maxout1200]

Think you better explore the rear diff and make sure there is not something floating around that is binding it up. Thats the only way it could be putting excessive pressure on the drive shaft. Maybe it was a fluke and U got a defective part. Was the replacement shaft new? Check the wheel bearings and rear brake also while you are at it.

 

[one2dmax]

There had been a bad batch a number of years ago but I dought that it's the problem. If you are using the double d and are banging second gear holding the throttle wide open then that is going to be part of the problem. You'll either need to let up when you shift or take some of the clutch out of it.

not installing the rear mounts may be a small part of it as well as a possible rear diff (only if it's broken the pinion which is common).

Sean

 

[jfeagins]

Max shafts aren't exactly known for the durability under repeated heavy stresses. Metal by definition is more brittle the colder it is. Theoretically, you won't be as likely to snap one in a warmer climate as you will a colder climate

Are you making sure you have the slack out of the driveline before you dump the clutch?

I always snapped mine while going into 2nd gear. I also toasted a u-joint going into 2nd.

Is it just me and my limited garage and tool situation, or are these two parts a ****** to change out for everyone?

 

[one2dmax]

Nah, not too bad to change. Wait until you have to change a block from cracking it from too much stress. Of course transmissions aren't nice to change either but easier then the block.

Sean