Play in the drum of a 6401

[wendell]

I was cleaning up my saws today and saw that after I had pulled the bar off my 6401 and was cleaning around the sprocket, there was some play in the drum behind the sprocket. I compared it to my 7900 and there is no play there.

Is there something that needs to be tightened or replaced or is a little bit of play OK?

 

[DMShaver]

Play in the clutch drum would indicate that the bearing is bad. Remove the clutch drum and inspect the bearing. It may need to be replaced.

 

[wendell]

I probably used the wrong word. I am asking about the next part in from the sprocket, possibly the clutch cover? I removed the sprocket and that piece and everything internal from there is solid. There is a little play in the "cover" on the shaft but the splines that contact the shaft appear to be in good shape.

How I found this in the first place was I was pulling the chain along the bar and was getting an occasional ringing sound which I now believe was possibly a cutter contacting this "cover" as it does sound like a bell when you hit it.

Your thoughts on that and also how do you get the circlip back on? :blush:

 

[striperswaper]

still sounds like a clutch bearing
how about a pic?

 

[DMShaver]

I'm still unclear as the exact part you are talking about. Using the following address, http://www.dolmarpowerproducts.com/files/downloads/166/source.pdf, could you identify the reference number of the part you are talking about? Then I can better advise you on what the problem/solution might be. As far as getting the E-clip back on, the easiest way is to start it in the groove, place the large (3/4") end of your saw wrench over the clip and pull it into place. This ensures that you don't damage the saw, the clip, or more importantly yourself.

 

[wendell]

Part #141, the clutch drum and i guess by default #142, the needle cage. Thanks, that certainly made things easier!

 

[wendell]

Sorry for the quality, I'm sure there is a way to get in closer and not have the flash wash out the picture, but I don't know what it is.

 

[striperswaper]

was your clutch drum hitting your crankshaft? the ringing you heard?

 

[wendell]

I'm not sure. I still had the bar on when I heard it and then saw there was a little wobble in the clutch drum and thought I would check it out with you guys.

I figured it would be better to be safe than sorry.

 

[DMShaver]

Were you moving the chain back and forth along the bar when you heard the ringing? If so, it was probably the oil pump drive hitting the ears on the clutch drum. This is normal.

 

[striperswaper]

so after all this ...
tell us what the bearing looks like...is it there?

 

[wendell]

That's exactly what I was doing. Thanks!!

I had the cover off both the 6401 and my 7900 and gently tapped the clutch drum on both with my scrench. The 6401 sounded just like a bell but the 7900 was just a dull metallic thud. Thought that is interesting and of course, that difference is what started this all.

Now, however, I have created another problem. I put it all back together in what I am sure was the right order but the e clip didn't quite fit so I took apart the 7900 and saw that one of the washers (there are 2 even though the parts diagram only shows one and on the parts diagram it is called a disc, part #145) was in a different place than what I had. I re-ordered them and now the e-clip fits but the sprocket and bar don't quite line up which of course, the chain isn't very happy about.

And now that I think about it, my 7900 doesn't have either washer where the diagram shows part #145 to be.

Can you tell be what the correct order should be?

Thanks guys, I really appreciate your help!

 

[wendell]

so after all this ...
tell us what the bearing looks like...is it there?

The needle cage, part 142 is there and looks fine.

 

[striperswaper]

sorry can't help myself
are the needles there, intact within the cage?
put some grease on the bearing, get the washers in the correct positions
carefully put your Eclip or circle clip on and you are good to go as long as you don't hear any bells ringing

 

[wendell]

Yes, they are all there.

If they were bad, how would you replace that needle cage? (Just trying to learn for the furture here. )

I bought both the 7900 and 6401 used so not sure what all happened to them before so pretty sure I shouldn't depend on how the washers are ordered. Probably a dumb question but can they be rearranged to line up the sprocket with the bar?

 

[DMShaver]

You have a rim sprocket, so the thickness of the washers, no matter where you put them, is not going to make that much difference. The rim floats on the clutch drum. I realize that the IPL shows the washer on the outside of the clutch drum, but I will sometimes put it on the inside IF the drum is rubbing the clutch. To tell if this is the case, put the drum and bearing on the crankshaft and while lightly pressing on the drum, rotate it by hand. If you feel or hear it rubbing the clutch, place the washer under the drum. Then repeat the process and it should not rub. Many times when I set up a new saw, I will move the outer washer to the inside. As far as the E-clip on fitting back on, make sure that the ears on the clutch drum are not lined up with the oil pump drive. They need to slip past the drive tabs in order for the clutch to fit correctly onto the crankshaft.

In regards to replacing the bearing, if the bearing is separate from the drum, just the bearing can be replaced. If the bearing is pressed into the drum, it is often easier to replace the entire clutch drum. Either way, when ever you have the clutch drum off, place a dab of grease on the bearings and shaft to help lubricate them. This bearing is something that is often neglected and should be greased regularly to ensure maximum life, especially if the saw spend a lot of time idling. (idle is the only time this bearing actually gets used)

 

[wendell]

You remember that fairy tale where the cobbler had to make all the shoes and couldn't do it but the elves came each night and did them for him. I went out this morning and everything lined up perfectly and the saw runs fine. I have no idea what was going on yesterday.

Thanks for your help guys. I appreciate you taking the time.