Project Husqvarna TE610 Part 3: Dual Sport Adventure Bike Nut and Bolt

Project Husqvarna TE610 Part 3: Nut and Bolt Check
By Dan Barnes

More so than with any other vehicle I've experienced, it's proven necessary to strip all the covers off the Husqvarna TE610 and inspect everything, top to bottom. Every detail is an opportunity for a problem, and buying a brand-new bike would only have gotten me off the hook for a few parts and maybe an oil change. Almost no one part of it took much time or money, but it all needed to be done.

Start by cleaning the bike. If you can't see the parts, you can't tell that something needs more attention. Motul Moto Wash gets most of the bike super clean, super fast. A more aggressive degreaser or solvent may be called for on heavy grease and oils, but Moto Wash is a nice option in between car wash soap and something that will clean the chain.

Kick stand
Husqvarna's mechanism to prevent the bike being ridden with the kick stand down is a peg on the kick stand bolt that causes the return spring to raise the stand automatically whenever it is unweighted. This makes it incredibly inconvenient to handle the bike when you're not riding. Some owners have even had the kick stand drop their bike due to vibration while the engine warmed up at idle.

You can use a hack saw and file, but I convinced a friendly machinist to part the peg off the end of the pivot bolt cleanly. With the return spring pulling straight, it holds the kick stand in the down position. While I was in there, I made a HDPE washer from 100 percent post-consumer material (an empty milk jug) to put in the kickstand clevis and take a little bit of the slop out of it.

Schrodinger's Nut
The 38mm-hex nut that holds the primary and balancer drive gears on the end of the crankshaft under the right-side engine case cover was not properly tightened on many TE610s. On some bikes, the nut is nearly finger-loose, on some it moves a little when torqued to the proper value, and on most it is just fine.

If the nut loosens, the Woodruff key that is meant to hold the gear in position on the shaft during assembly has to transmit all the pulsing drive torque and eventually breaks. Once it fails, the gear spins on the shaft. Drive no longer passes to the transmission input shaft, and the balance shaft goes in and out of phase with the crankshaft and piston. The bike alternates quickly between running smoothly as designed and vibrating twice as badly as if there was no balance shaft at all. It's likened to riding on and off a strip of Botts dots on the road, but much more severe. It's “pull over and call a friend with a truck” time.

If the Woodruff key fails, the best case will require pulling the clutch basket off the transmission input shaft so the crankshaft gears can be removed and the key replaced. Fortunately, the Woodruff debris is generally captured by the gears, washer and nut, so it doesn't tend to scatter bits through the engine. The key is a standard size available through normal auto parts sources.

This problem was noticed in 2006 and carried on at least into 2008. I'd consider it a possible problem at least to the end of 610 production, especially given the simplicity of checking it. It's best to take a proactive approach: If you don't know the nut has been torqued correctly, assume it may be loose and get after it.

I used a 1 1/2-in socket (because it was easier to find than a 38mm) and had Mark DiBella of MD Automotive trim it on a lathe so the internal flats extended all the way to the end, giving maximum grip on the thin nut.