Husqvarna 257, 261 chain tension screws falling out

[Mattyo]

I did search for this and didn't find an answer....

Dad has a 257 and a 261 ... both run fine, but the other day he was cutting and noticed the 261's chain was loose. Went to tighten it... the adjustment screw had FALLEN OUT. crud... ok, time to buy new. Did that, new order comes, and no sooner had he got the 261 fixed .....he was using his trusty 257, and the SAME BOLT fell out of it!

this is the bolt....for reference only....

http://www.ebay.com/itm/Chain-Adjus...928?pt=LH_DefaultDomain_0&hash=item5d4a754910

he's had the saws for many years, and cut plenty of wood. what the heck? what is he missing?

oh, and it was good thing we bought two

-Matt

 

[295 tramp]

That little square piece nylon is what holds the chain tension screw in to place. you run the screw threw the case
and thread that nylon piece on then the stud. then screw it in until the nylon piece reaches the cut out in the screw.
That's all that holds it.

 

[Mattyo]

Could that little piece have broken on both saws at the same time? ...seems like an e clip would have been more effective here

 

[Sierradmax]

yes, the piece gets brittle overtime and may have fallen out when the bar was taken off and the bar plate came loose.

What I don't understand is the bolt is engaging threads in the dowel to tighten the bar and use the saw. That dowel must be real close to the end of the bolt and loosen under vibration in order for it to fall out.