Hi all. We run a Husqvarna 435. last week I ordered a new chain for it. Put it on, within 20 minutes the bar nose wheel was seized. Cleaned out with aerosol brake fluid, put it back on. Seized again quickly. We scratched out heads for ages, eventually changed back to the old chain- all runs fine for the next 5 hours. I checked the new chain, it is the correct one for the bar and identical to the old one (Husqvarna genuine). The only other thing we changed was the oil we were using, but it works fine and the nose wheel doesnt seize with the old chain on. Could it be the new oil only works with a chain with a certain amount of wear or something? Any thoughts? Any advice greatly appreciated. J
Seizing nose wheel- but only with a brand new chain
- Thread starter JonnyK28
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Show a pic of the nose sprocket teeth. Sounds like they may be worn. Did you change the drive sprocket as well?
^^^^^
Pictures of both sprockets, and the drivers on each chain.
How many chains have been used/worn out on the bar and drive sprocket?
Pictures of both sprockets, and the drivers on each chain.
How many chains have been used/worn out on the bar and drive sprocket?
Thankyou for your time guys. Its a pretty new saw and not done that much work- the bottom chain in the picture has been on the saw since new- so you can see how much it has(nt) done. Pictures attached:
2 chains- top is new, bottom is old
Drive sprocket- again, fairly new, not worn
Nose sprocket- new bar with saw, again I dont think its worn
@Mad Professor
@buzz sawyer
Thanks again
2 chains- top is new, bottom is old
Drive sprocket- again, fairly new, not worn
Nose sprocket- new bar with saw, again I dont think its worn
@Mad Professor
@buzz sawyer
Thanks again
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That's about the most wear I would like to see on a drive sprocket. The second pic of the nose looks questionable. Can you put the chain on the nose sprocket with the nose up so the chain is resting on the sprocket? If the bottoms of the links touch the nose of the bar, the sprocket is worn. The chain should ride on the teeth of the sprocket, not touching the bar.
Thanks @buzz sawyer and sorry, I know the picture quality is poor. Attached is pic, it is riding clear of the bar. I think the drive sprocket photo makes it look worse than it is, but if it is that, how does that affect the nose wheel seizing?
Cheers
Cheers
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fishdrivel
ArboristSite Operative
Have you greased the nose sprocket?
When I was cutting dead ash I would get fines in the nose that would lock it up.
Happened more often with new chain than old one.
What are you working on tree wise?
Happened more often with new chain than old one.
What are you working on tree wise?
SteveSr
Addicted to ArboristSite
I see side wear on the nose sprocket like running a .058" chain on a .063" bar.
What is the gauge of the bar?
What is the gauge of the chain?
That looks ok. I was thinking you meant the links were binding - my bad. Someone mentioned more fine sawdust with a new chain but I would think just the opposite. Are you sure it's getting enough oil? Chain not over tensioned? Maybe try running the new chain just slightly looser for a few cuts to see what happens. Someone mentioned greasing the bearing - I don't see a hole in the one photo. I normally don't lube mine - the bar oil takes care of it.
Replace the bar the tip sprocket is worn down to the point the chain drivers are bottoming out and breaking the points off. The chain appears to be off the bar at the tip but if you look closely its hitting the bar where it enters the sprocket and where it exits it. Likely the original chain tie straps are worn to the groove of the bar, im betting the bar rail has a sharp edge in the tip the pictures do not show. This is why I stopped getting laminate bars, the tips and sprockets are now so soft they do not even last a whole chain..stihl/oregon have both done this garbage to sell more bars.
Did you clean all the gunge out of the bar groves before using the new chain? New chain will be a tighter fit in the grove and might be scraping dirt out of the grove and carrying it into the nose sprocket.
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Looks like it has done a lot of cutting with the bar buried based on all of the paint being worn off.
I had a 435 a while back that did this. After cuting a while it would sieze up when hot.
Seems like there just wasnt enough oil or the bar was tired/not heavy duty. Greasing the nose sprocket bearing regularly helped it get by but I eventually moved on to a new Oregon bar and it was fine.
I had a 435 a while back that did this. After cuting a while it would sieze up when hot.
Seems like there just wasnt enough oil or the bar was tired/not heavy duty. Greasing the nose sprocket bearing regularly helped it get by but I eventually moved on to a new Oregon bar and it was fine.
calamari
ArboristSite Operative
I'm not so sure that happens. When the chain goes around the sprocket and the tip, centrifugal force wants to throw the oil off not into the bearing. The tip bearing is buried pretty deeply in the nose which I guess is why they have you lube it on most bars. Strangely, some bars don't have a provision to grease the tip which I guess is so they fail quicker and they can sell another bar or nose sprocket. This bar deals with getting oil into the nose but it looks to me that it cuts the oil supply off which is in the bar's top groove leaving the bottom of the bar under lubed. Probably.
It looks to me like someone put a 3/8” (.375) chain on a .325 saw and bar. That would explain the troubles.
JQ
JQ
Thanks everyone. Just to confirm:
- It has never run the wrong chain on the bar- same chain since the bar was new. Gauge is 1.3mm for bar and chain (050, Husq SP33G)
- We have never had to oil the nose sprocket on any of our saws before (we tried on this one, but even using brake cleaner and then putting oil/grease in the bar end hole, it would seize up the same)
- Everything works fine with the old chain, with all else equal to when the new chain seizes it
- Happens in all types of wood (lots of ash and oak recently)
- Every time it seized we cleared out the gallery and nose sprocket completely of debris, oiled and refitted chain
- I do believe it is because the nose sprocket isnt getting enough oil delivered via the gallery, and debris was getting into the nose sprocket and jamming it but the question is why only with the new chain??!
Thanks again, I think we might try a new bar with the new chain and see what happens!
- It has never run the wrong chain on the bar- same chain since the bar was new. Gauge is 1.3mm for bar and chain (050, Husq SP33G)
- We have never had to oil the nose sprocket on any of our saws before (we tried on this one, but even using brake cleaner and then putting oil/grease in the bar end hole, it would seize up the same)
- Everything works fine with the old chain, with all else equal to when the new chain seizes it
- Happens in all types of wood (lots of ash and oak recently)
- Every time it seized we cleared out the gallery and nose sprocket completely of debris, oiled and refitted chain
- I do believe it is because the nose sprocket isnt getting enough oil delivered via the gallery, and debris was getting into the nose sprocket and jamming it but the question is why only with the new chain??!
Thanks again, I think we might try a new bar with the new chain and see what happens!
Might depend on the bar. I can tell you that I rarely grease mine and have never had an issue. In fact, some bars have no provision for greasing. If centrifugal force were that much of an issue, wouldn't the grease be thrown out as well?
Looking at the last photo of the two chains - which is new? Almost looks like the drive links on the upper chain are a bit longer than the lower chain. Maybe the new chain is clearing more sawdust out of the bar groove and forcing it into the nose? Maybe already answered, but did you clear the junk out of the bar groove? You definitely have a stumper. I respect your dealing with this frustration!
The grease does get thrown out, I like to grease the tip to push out saw dust, dirt etc before starting the saw or after changing the chain.
Some oil flings from centrifugal force for sure, but there is plenty that moves along in the gallery and is delivered to the nose sprocket. I have never oiled or greased a nose sprocket before, and they have always run freely, even for hundreds of hours cutting.
