Bar Studs and Nuts

[TheTreeSpyder]

Now that i nave your attention.....

i got an 034, 044 older Stihls with the same problem, loose bar studs that have been replaced and 1 already heli-coiled, both forward, i believe terminating in the oil sump.

Mech. says that the Stihl knowledge base says that the only known cause is from overtightening and/or olde bar nuts! They say that new studs can get unusable from olde nuts. That continuing without that simple change of nutz and another set of new studs; could evolve to the saw being unusable, especially already heli-coiled 034.

i wonder if that is why RB chose that 034 for capstan winch powerhead, in an non-oiling application? i really like the lil 034, carries a 3/8 x 16" cutter very well; worst thing is all the screws are smaller than most on Stihls today, so have to carry some just 'in case kit'for it seperately!

So anyway they seemed to recomend routine replacement of really loader bar nuts as a long term wearable item. Guess that makes sense.

 

[stihltech]

bar studs

Only 2 things I have witnessed pull out the studs, overtightening and not keeping the stud tight in the case. The guys with a conatantly sharp chain never have a problem. The guys with the dull chain constantly has a stretch problem , so he tightens the bar nuts more to keep the bar from slipping. Bars don't slip, chains stretch from heat, bad sprockets and bar noses.
The best thing I have seen is a shorter bar wrench, less torque. And ,of course, a properly sharpened chain.

 

[TheTreeSpyder]

Over tightenning did come up, and i think we have some problem there. These are probably my oldest 2 saws (of 12), and i bougt'em used years ago on top of that. So their analysis seemed feasible about nut wear after so much loosening, tightenning, vibration etc.

 

[Stumper]

Personally I think bar studs are nuts. They never know what they'll wake up with or what diseases they may have contracted.

 

[Oregon_Rob]

I have an old Jonsered with one of the helicoils pulled out and the other loose. Has anyone ever tried using any kind of liquid metal product to fill and re-tap the holes or bond in some kind of insert? I have heard rumors of people doing it with striped out head bolts on car engines.

 

[sedanman]

I've had much better luck with "time serts" than with heli-coils. The time sert is a solid tube with threads on the inside and outside, requires a bit more metal around the hole but when installed with stud and bearing grade loctite they're much better than the flimsy wire coil of the heli-coil. Madsens has em but I think you could get them cheaper through your local auto parts store or machine shop.