Service & Maintenance Question
I have four Husky 435s that I use for Precommercial...escalated
Service & Maintenance Question posted July 31, 2013 by Howard Wilson
308 Views, 8 Comments
Question:
I have four Husky 435s that I use for Precommercial thinning, stand release, cutting trails and brush clearing. On all four of my saws, the chain plate guide fails after about 15 to 20 tanks of gas. That is, the chain cuts completely through the chain guide plate. All of my saws are stock with Husky chains and bars. I always keep my chain tension fairly tight. Is this normal to have the chain guide plate fail at 15 to 20 tanks of gas? Why doesn't Husqvarna use steel for the plate instead of a softer metal?
Answer
Howard,
The guide plate or bar shim plate should only get an occassional scrape or scratch, I have chainsaws that have been in use for over 30 years and the shim plates are just fine.
I would look elsewhere for your problem, three thoughts come to mind, one thought is bar wear, where the groove of the bar or rails of the bar are allowing the chain to flop back and forth or left to right. If the chain is staying true in the bar then the chain should never hit the shim plate.
My second thought, and not in any specific order but I would check both is the drive sprocket is worn allowing the chain to move over on the sprocket, and not centered on the sprocket, if the chain moves to far in on the sprocket then it will also hit the guide plate.
And one last thought is the bearing inside of the drive sprocket may be worn allowing the drive sprocket to tilt up or down, the drive sprocket bearing should maintain the drive sprocket in the same rotational plane as the engine crankshaft, If this is not happening and the bearing is worn out then yes, the chain will hit the guide plate.
Please check out those three areas for problems.
I hope this helps.
PS. Also the sprocket needle bearing should not be wearing out If it is properly maintained, lubricated and cleaned periodically, (Note:check for play or looseness in the drive sprocket with the bar and chain removed), but they are also reasonable to just replace periodically too!
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Dear Karla,
This has happened to all four of my Husky 435s. I've gone through a total of five chain guide plates. They are all relatively new, 15 to 75 tanks of gas per saw. I have an Echo with a steel guide plate with over 125 tanks of gas through it with no guide plate issues.
My bar wear is good and I file the bar if needed.
The drive sprockets and bearings are in great shape and I lube them when I replace the chain guide plates. I also lube the needle bearings every 10 to 20 tanks of gas.
I do cut a lot of brush and small trees as I build trails and do stand release and precommercial thinning.
I think the problem is the weak metal in the guide plate. It gets cut completely through. I think the saw cutters (which I keep very sharp) hit the guide plate when cutting through small limbs and brush. This never happens with my Echo saw (I think the cutters just bounce off the steel), doing the same work.
Sincerely,
Howard
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Howard,
It is kind of strange that all four of your chainsaws would do the same thing.
I looked at the IPL for your saw, and compared it to my 455, and they look very similar, I have three of them and no scratches on the guide plate, its also a different number guide plate on my 455, so I don't know if it would fit a 435, but my guide plate is pretty substantial metal plate.
Anyhow, I am curious how close is your chain to the guide plate? Here is a simple measurement method. Remove the brake cover, leave the bar and chain inplace, using some spacers/ or washers put them on the bar bolts followed by the bar nuts. You just need enough spacers, so that you have bar bolt threads to tighten down the bar. "Do Not Run the saw like this", This is strictly for measurements with the saw shut off. You can also pull on the bar while you create some manual tension, and tighten down the bar buts. Now with a gloved hand pull on the chain a couple revolutions, and watch the clearance of the chain to the guide plate. How close does it get? And does the chain hit the guide plate ?
This may give some idea of what is wrong, and why the chain is hitting the guide plate in the first place.
I hope this helps, I am going to check the clearances on my 455's and will let you know! Maybe there is a design difference in the guide plates between a 435 and 455.
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Dear Karla,
Attached is a picture of my damaged guide plates. The one in the upper right corner is brand new and in perfect condition. All of the others were cut up by the chain. I measured the gap between the cutters and the guide plate. It is .040 of a inch, I used a feeler gauge.
i think the cutting of brush and small limbs sometimes pulls the chain partially out of the track and it contacts the guide plate. If the plate was steel it would bounce off. However, the plate is much softer that the cutters and they cut right through the plate. Note, Echo uses a steel plate and I've had no problem with Echo saws cutting brush and small limbs.
Sincerely,
Howard
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Howard,
I just came across a link for a guide plate, and yes it says it will fit a 435, and a 455, so it might be a heavier plate?
http://www.ebay.com/itm/New-OEM-Husqvarna-Clutch-Cover-Wear-Plate-544250501-340-345-350-435-440-455-460-/190823467298?pt=LH_DefaultDomain_0&hash=item2c6df70922
Check it out, Oh it looks like a good price too!
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Thanks for the pictures, I opened your message and pictures, after I sent the previous message. I am speechless after seeing the pictures. Also the .040 measurement sounds way too close, I don't think my 455 is that close but I haven't check it yet. Also, are you using the standard sprocket on your chainsaws, I have switched mine to power mate sprocket with floating rims, I wonder If that could be making a difference? But in either case you shouldn't have to re-design your own chain saw, so there must be something definitely wrong. I still have a difficult time understanding that the chain is suppose to hit that guide plate! That doesn't seem right either!
I hope a Husqvarna representative, Jumps in here and gives a good answer, I have taken these Husqvarna Saws completely apart and put them back together, fixing all kinds of problems but this one has me stumped.
I will check my clearances on my Husqvarna's tomorrow! Maybe that will shed some light on the guide plates.
Again, I now really understand your problem.
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Dear Karla,
I'm using the standard sprocket, everything is as shipped from the factory. The chain doesn't touch the guide plate at rest, just under rough cutting situations. I don't think I would be having this problem if I was just bucking logs but that isn't what I need the saws to do.
Some of what I have been doing is opening up old trails that are overgrown. I start about 6 feet off the ground and the right side and cut down to about 6 inches off the ground. I'm cutting through doug fir, vine maple, alder, cedar, maple and wid cherry limbs at varous angles, salmon berry and blackberries. Then I cut the left side about 6 feet away. After that is cut I take a step forward and repeat. I'll cut 500 or 600 feet in an afternoon. I'm sure it is hard on a saw but that is what high quality saws are for. That's why I buy Husqvarna.
Another use is precommercial thinningwhere I often have 2,500 trees per acre, 1 to 5 inches in diameter. I'll cut about 2,200 trees per acre, the smaller ones. All of the cutting is from the side (horizontal), there is a lot of pinching and binding, and a number of cuts are "push" cuts with the top of the chain saw bar. That's the nature of the game and again why I buy Husqvarna.
I'm 63 YO and in most of my cutting I'm carrying the full weight of the saw. Thus I go with a smaller, lighter saw like the Husky 435.
Sincerely,
Howard
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Howard,
I went out to my chainsaws today with feeler gauge in hand, and ready to remove the clutch cover when I realized I could see everything without removing the cover, and with normal tension on the chain. While pulling on the chain the closest cutter got with a 1/4" (.250"), and if I pryed with a screwdriver to move one of the cutters towards the guide plate, the closest it would get would be about 1/8" (.125"). The closest point is near the drive sprocket, I tried to pry the cutter over near the chain guard but it wouldn't budge it stayed at 1/4 ", so near the front of the saw the chain will never hit the guide plate. I also took some pictures, Unfortunately I am neither a photographer or a Photo shop person, so the picture is fuzzy and could only post one picture.
Anyhow, I know that doesn't help your problem, and my chain saw is a 455, not a 435, so they are similar but Not the same. Your .040" measurement is definitely way too close, but I'm not sure why? It is also very strange that all four of your chainsaws are doing the same thing. It almost seems like the drive sprocket is too close to the guide plate if the chain can move so close to the guide plate.
I also took a picture of the underside of the chainsaw so you could see the drive sprocket and the guide plate, and the chain clearance to the guide plate. (see attached file)
This problem does have me puzzled, and I am just curious, Is everything factory original with no modifications to the clutch or drive sprocket? Have you taken the four chainsaws clutches and drive sprockets apart ? Can you check the IPL drawings for the parts and pieces of the drive sprocket and clutch, and compare to your saws to make sure they are not missing a spacer washer, or assembled with the spacer washer in the wrong place, Just a thought!
I hope a Husqvarna Representative has a solution for you, sorry I couldn't help!
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