038 chain tightener

[welderskelter]

Is the chain always getting looser on these or is there something I can do to keep the tightener from backing off. Dont have any problem with the 066.

[sawguy21]

The tightener doesn't hold the chain in place once the bar nuts are tightened. Is it getting adequate oil? Are the nuts bottoming on damaged threads?

[welderskelter]

Sawguy I thought I tightened them plenty.Probably as tight as the 066 and they always loosened up. Ill go tighter Thanks

[Mad Professor]

Is the chain always getting looser on these or is there something I can do to keep the tightener from backing off. Dont have any problem with the 066.

I'll assume the bar/chain/drive sprocket are in good shape, and match in pitch and gauge.
When tensioning the chain, lift up on tip of bar.  When chain is snug, then tighten down nuts.
Never had an issue with chains on my 038s

[Al_Smith]

Couple things to keep in mind .The 038 is old enough it might have small flanged headed  bar nuts .The larger nuts ,some with a flange head will gain more purchase than the smaller nuts .Those aren't expensive and after market work as well as OEM .Some of the less expensive brands of chain have a tendency to stretch with use .Not much you can do about that except stop buying cheap chain .
Some time ago I bought several loops from a former sponsor of this site at 10 bucks for a 20" loop ,72 driver .375 .I got exactly what I paid for, junk .Live and learn .

[welderskelter]

I guess I am good then. Since I have three of them I am glad its not a trait of them.

[joe_indi]

Sawguy I thought I tightened them plenty.Probably as tight as the 066 and they always loosened up. Ill go tighter Thanks

If seating area for the bar  on the sprocket cover is worn out the cover will not hold the bar tight, however much you tighten it. That unworn area between the holes for the studs will ensure that.
Just grind off this unworn area and it might get tight. Otherwise you might need to use washers between the bar and the cover

[Al_Smith]

Just a tid bit in case you don't know .The cover for an 024 is a direct fit for an 038 .Something to remember if you use e-bay because they usually sell cheaper than an 038 cover .Rather unusual for Stihl  to make many parts that interchange, this is one of them . ;)

[Mad Professor]

One more thought.

If the saw is filthy and has oily debris between the bar and case/chain cover that would cause a problem.