1975 850

[commander]

Thanks for all the reply's so far, i am bringing back to life my 850 t . Had to rebuild the tranny , back together now.
My question is the swing arm pivot preload , the big nuts on either end . how to set ?  Thanks

[slopokes]

With a big wrench

[Chuck in Indiana]

It's just a jam nut. The swing arm is loaded with the pins. The pins just touch with enough pressure to keep from having any slop. You can feel it. Make sure the screws stick out the same on both sides, hold them with your wrench, and snug up the jam nut. All it does is keep the pins from rotating.

[giusto]

With a big wrench

"wrench envy"

[Kiwi_Roy]

If ever I need a wrench for a large nut like that I carve one out of 1/8" Aluminum.

The length of the flat is also the radius of the circle and 1/6th of the circumference.

A coping saw and file makes short work of the metal.

[Antietam Classic Cycle]

It's just a jam nut. The swing arm is loaded with the pins. The pins just touch with enough pressure to keep from having any slop. You can feel it. Make sure the screws stick out the same on both sides, hold them with your wrench, and snug up the jam nut. All it does is keep the pins from rotating.

Some early Tontis (V7 Sport and maybe the T?) have a screwdriver slot in the pin instead of a socket for an allen wrench. 

[acogoff]

     I put a reference line on the pin with a fine sharpie marker so as to make sure I don't tighten it more while snugging the jam nut. Just for peace of mind. You can also tell if the screwdriver turns, but I still like to mark close to the center of the pin as so you can see it through the hole when done. And my old T3 has the shallow screwdriver slots in the pins, but it all works out just fine, just need a high quality screwdriver of the proper size.

[commander]

Thanks, it has a flat slot.