clunking noise when rotating chain by hand on 034

ross_scott · Oct 8, 2005

Guys when rotating the chain by hand checking to make sure the chain moves easily while tensioning the chain or when moving the chain while sharpening I am hearing a clunking noise I am suspecting that the roller bearing in the clutch drum may have stuffed out this is concerning me as I am hoping like crazy that it is not the bearings that sit in the side of the crank case I don't hear any bearing rattles when running the saw. the chain I am using is 3/8 the drive sprocket is the 3/8 7 tooth bar size is currently 16" Oregon power match I do have a brand new 18" rollomatic E bar to go on it I am just waiting to pick up the chain for it. what would your opinion be I am hoping it is just a 20 dollar bearing to fit into the clutch drum. before i forget I have put a fresh coating of grease on the bearing

Fish · Oct 8, 2005

Has the sprocket/ chain got a lot of wear? You can get a new sprocket bearing from Oregon a lot cheaper if you need one.

HiOctane · Oct 8, 2005

The noise is probably the chain coming out of rim teeth,it usally makes a clunking noise,not big,but worst if chain and the rim is worn.Remove the chain and bar and start the saw to check if you still hear the noise,you will have the answer.You could have maybe a drive link broken on the chain too making noise.Check also if there is any endplay on the crankshaft end indicating bearing or case failure.

ross_scott · Oct 8, 2005

I have checked for play on the crankshaft and there is no play in there so atleast that is eliminated started saw with no bar and chain no bearing noises I cant see any wear on the drive sprocket so I will get a roller bearing and replace the one that is already in it

Lakeside53 · Oct 8, 2005

Unless the clutch drum bearing is totally trashed, this isn't your problem. Spin the clutch drum by hand (no chain). It should be smooth. Position your fingers across the drum and see how much "wobble" it has.. Some wobble is normal. If it does wobble excessively, it's likely the drum that's worn, not the bearing. Replace both if you do put on a new drum. If go for a new drum, get the rim kit version with the bigger bearing.

If your chain sprocket is worn, it will click or clunk as the chain jumps in and out of the wear grooves. Spec max wear is .5mm, but most people hang onto them much longer.

ross_scott · Oct 8, 2005

Lakeside53 said:
Unless the clutch drum bearing is totally trashed, this isn't your problem. Spin the clutch drum by hand (no chain). It should be smooth. Position your fingers across the drum and see how much "wobble" it has.. Some wobble is normal. If it does wobble excessively, it's likely the drum that's worn, not the bearing. Replace both if you do put on a new drum. If go for a new drum, get the rim kit version with the bigger bearing.

If your chain sprocket is worn, it will click or clunk as the chain jumps in and out of the wear grooves. Spec max wear is .5mm, but most people hang onto them much longer.

Just did what you said to do the clutch drum spins smoothly and there is some wobble but not much. So it may be the rim sprocket. there is a new chain and bar going on the saw tomorrow so I will see how it goes with that if i still get that noise I will ask my tutor if I can borrow one of the brand new chain sprockets for the stihl saws we use and see if that fixes the issue if it does I will pick up a new sprocket from the dealership. cheers for your help so far.

ross_scott · Oct 9, 2005

It wasn't the sprocket it did turn out to be the bearing. Also went through and replaced the cylinder gasket seeing that I wanted to check the piston and cylinder for any bad scouring and it all looked good heaps of compression. Also I decided while the muffler was off that I would try drilling out a couple of the holes in the baffle to 8.5mm instead of the crappy little holes the baffle had put it all back together started it up and it was idling very fast so I had to back it off to stop the chain spinning. now at the shop getting carb tuned