greenmonster wrote on 04/30/12 at 10:22:57:

I've done it,.. multiple times... and not even a scratch...

 
OK. now we kick over into the next part of the Tech Post, spline maintenance.

Those of you who have heard the "playing cards in the bike's spokes" sound on deceleration understand what I am talking about -- when simple wear has increased the shaft spline to pulley spline clearance to the point something has to be tried to stop it or it will progress faster and faster to failure.

I've heard JB Weld and I've heard RTV and I've heard speciality stuff from Loctite corp ---- what have you guys actually used that fixed the issues.





And were you ever able to get the pulley off again when you needed to ?

I think I'd just smear JB around the shaft splines n' slide the pulley on...

There have been instances of the pulley chewing up the shaft spines,... haven't there?... Seem to vaguely remember one...
That's a scary thought...

OK, before we start to gooping, you need to measure the side to side rock potential on your worn pulley.

Put the cleaned pulley on the splines and rock it looking for tilt movement.   Mine would do a 1/6" of an inch and my wear on my splines is very mild.

You need to be mindful of getting an even settlement of your gooped pulley during torque down and you need to check the evenness of the pulley both for tilt and run-out BEFORE you go for the final clinch up.  

Why?   If you clench up crooked and let the RTV (or JB Weld if you are at that stage) set up crooked -- guess what, you got a vibration/noise from a front pulley that is running crooked.  You don't want that.

Now on to the gooping, having been all properly warned and all ....
 


Shaft is in great shape, practically virginal.   No issues here.




Some RTV on the shaft splines .....




Some RTV in the ID splines .....




Some loctite on the threads and a goodly whapping with the impact wrench.


Looking at the ooze, I see some width & thickness to it.   This means the RTV inside the joint got itself squeezed by the pull down with the impact wrench.   Assuming there was a similar internal pressure squeeze effect, then the joint between the splines got force extruded pretty full of pressurized RTV as well.   The movement would be through the splines and into the air gap under the spacer that the transmission seal runs against.

I dunno, but I think we got us a fairly good RTV encapsulated joint here which unfortunately I still tend to think is only going to be a temporary fix at best.  

Still, we gotta try the less extreme fix first to see if it is worth anything at all.

I think you totally misunderstood this part of the thread.

It isn't really about recovering already severely torn up splines, it is about attempting to prevent the spline wear progression from progressing by doing this very early on, just as soon as motion is first detected.


======================


What is known about severely progressed spline wear?

Serenity is your man for that, he has killed two sets of splines on pulleys and one and a half sets on engines.

His last attempt at fixin' his extreme spline slop involved driving a series of 2-3 little hard tack nails into each of the spline gaps trying to put the driven surfaces next to each other in a more permanent way.

Attempt before that was JB Weld.

Neither fix lasted more than a year or two.

Longest lasting, most drastic fix that has been done is to align the splines into contact, tighten the nut down good with no washer under it then spot weld the nut to the shaft, then spot weld the nut to the pulley.

This works, but it means you cannot take the belt off ever again.  End game on this fix is the splined/treaded end of the shaft breaking off after years and years of the threaded shaft end taking all the load from the engine.

Next factoid is that a full engine tear down to switch out the shaft cost more than a cheap used engine.   When this was figured, an engine cost $350, with them running up around $550 now days the math may not work out that way any more.  

So, since you have a new engine get a newish pulley and try the RTV trick as it lasts at least 2 years (date since installed).  It can't hurt and it would hold some at first, then act as a sort of impact resistant lubricant after the motion actually began.

As far as me tearing down the junction to look at it, no, that ain't going to happen until I hear it break itself loose again.   So far that hasn't happened.

You know, the chain conversion guys have the exact same problem about wearing out the drive splines on the output shaft.   Their actual chain sprocket to splines engagement area is actually less than what the pulley guys have, so logically they should hit the spline wear out wall sooner.

We don't hear about this happening because the chain drive guys tend to sell the bike off before it wears out the drive shaft splines
(they also tend to be relatively younger folks who change bikes frequently).

Us old farts who ride the Savage because it fits our creaky old bodies so well, we tend to keep the bike long enough to wear things out.

Key thing is to keep  your nut nice and tight and to check it periodically to see if it has gotten loose on you.

If the pulley, washer and nut have never been removed from the original factory build is this still a potential problem? 25K on my 2006 with cam chain tensioner, tires, oil, filter and three valve adjusment checks as the only maintenance.