Harman slide plate/actuator issue

[P38X2]

Hello, pellet pals. Kind of a long post..

I've been having intermittent issues with my newer P38 for a while now. For the first couple months, everything was fine, then one day I noticed it making a repetitive clunking noise. I got under there and watched the bearing ride around the actuator arm. When the bearing first touched the arm, it clunked slightly. When it came off the arm, it clunked considerably. I only had maybe 35 bags through it at that time. I went to my dealer who recommended I clean the fines box and gave me a modified slide plate to try. The modification was the slight lip at the end of the feed plate was hammered flat and it was reduced in length very slightly to accommodate for the additional length gained from straightening the angle. His thought was the ramp on the end of the plate was causing fines to be forced under the plate, causing increased resistance.

I took it home, cleaned out the hopper and fines box and tapped around the hopper and actuator arm area to see if anything was lodged in there. Before swapping the slide plates, I put the fines box cover back on and the noise was gone completely. The bearing rolled over the arm perfectly. Hmmm. I must have knocked some krap loose in there. Finished the end of the heating season without incident.

Now this season, 1 month in, clunking. I repeated the cleaning/tapping process and quickly remedied the issue. Another 50 bags or so later, more clunking. I remedied it once again. I decided to go to the dealer again. Talked to one of the other owners. He recommended removing the deflector plate in the fines box. I thought he claimed it just made the newer style (smaller) fines box more cramped and more apt to have issues...like I'm having. He showed me on a demo assembly. Looked easy enough but I figured I'd wait to see if it does it again, which of course it did. Repeated my procedure AGAIN and fixed it....for 1 bag. While I was under there, I attempted to remove the deflector plate. Wasn't happening, not at the angle I was at anyway. Here I am listening to this thing clunk again and hoping one of you guys/gals have some input.

Few more things...
1) The fines box was never close to being full during any of the cleanings. MAYBE 1/3 at MOST.
2) It clunks with no pellets or fines anywhere in the system UNTIL I hit that unknown magic spot with my tapping method, at which point it's quiet again.
3) I highly doubt it's the pellets. They were never wet/damp and don't feel crumbly in any way, they're not unusually long or short, nor do they contain excessive fines.
4) I tried putting a little powdered graphite on the edges of the slide plate and working it in, to no avail.

So, any ideas?

 

[smwilliamson]

Slide plate is in upside down I betcha

 

[boosted3g]

Thats the only thing i can think of that can make that noise. Im not familiar with the new style fines box though.

 

[P38X2]

Thats the only thing i can think of that can make that noise. Im not familiar with the new style fines box though.

Slide plate is in upside down I betcha

From the factory? I've never had it out myself. What should it look like if installed correctly?

 

[P38X2]

Here's what it looks like from the hopper. Looks correct to me. Like I said, USUALLY when I get it to stop, the noise stays gone for a while. To me, the only places I can imagine it binding are the groove the plate slides in or the plate itself is too long and ANY slight buildup causes it to not shut completely and makes the bearing cam over on the actuator arm. Maybe the actuator arm is cut incorrectly and the tolerances simply aren't there to allow for any buildup. I'm leaning towards the latter cuz it's clunking when the plate opens AND closes. Seems to me the slide plate probably closes tightly against the fines box on that side and the rear would have plenty of clearance as the plate seals against the underside of the hopper, rather than the other side of the fines box at the end.

 

[boosted3g]

It is in the same way as mine although there is a difference in the plates. Mine is weled together rather than rivoted. Any chance those rivots are rubbing?

 

[P38X2]

It is in the same way as mine although there is a difference in the plates. Mine is weled together rather than rivoted. Any chance those rivots are rubbing?

Nope. The heads are well below the surface.

 

[Delta-T]

if you haven't done it yet, pull the slide plate and feel in front of it. you may have a pellet or something wedged in there. You will have to reach down from the hopper to feel for anything. The fact that the noise goes away is odd to me. Usually when you get something out of alignment or whatnot, the noise is pretty regular. good luck.

 

[P38X2]

if you haven't done it yet, pull the slide plate and feel in front of it. you may have a pellet or something wedged in there. You will have to reach down from the hopper to feel for anything. The fact that the noise goes away is odd to me. Usually when you get something out of alignment or whatnot, the noise is pretty regular. good luck.

I'll give that a try after work tonight. Gonna pick my dealers brain some more and see if its possibly a warranty issue.

I don't get it.

 

[P38X2]

Dealers advice... remove/clean/reinstall slide plate. Check fines box with small mirror for caked on crud. Remove deflector.

I'll post the results later tonight.

 

[Delta-T]

I have yet to see any problem caused by the deflector, but you may be that lucky person .

 

[P38X2]

It doesn't look like it would be an issue. There are some mysterious fresh looking scrapes on it near the top. I figured it was just from manufacturing/factory installation but now I'm wondering if it isn't bent or out of place and causing interference.

 

[Lousyweather]

ummm....seem to recall something quite some time ago about removing that deflector for some good reason. As for the "clunk", hard to say withoiut seeing it, but when the cam bearing comes off the arm, is it the arm falling due to gravity (which it shouldnt with pellets in the bin)?
Hm....i'd shorten the front of the slide plate ever so slightly and see what happens, I guess.....also, in your pic, the slide plate is correct- step side up.

 

[P38X2]

OK, problem solved...hopefully. After removing all the pellets from the stove the first thing I noticed was the slide plate was very difficult to remove. I don't mean accessing it, I mean it was bound in there good. I figured there would be a bunch of fines under it. There weren't. As shown in the first pic, the issue seemed to be the top of the plate scraping on the underside of the hopper. All I had was emery cloth, so I de-burred that area of the hopper as best I could. Next, as shown in the second pic, I sanded the bag out of the scored area. After this, I noticed the slide plate had a slight arch to it so I carefully hammered it straight. When I reinstalled the slide plate, it went in very smoothly, with zero resistance. I buttoned her up and now it's just a waiting game to see if the plate gets gouged up again and the stove starts clunking. So far, so good.

I think when I used the tapping method on the top of the slide plate, it must have set it down a bit and eased the binding. After a bag or 40, it eventually worked its way back up and ground against the hopper. My only concern at this point as far as not being 100% thorough in what I did was that the underside of the hopper wasn't sufficiently smoothed. If that's the case, it's just a matter of getting the correct tool, perhaps a small honing stone or a short file. I can't imagine needing to wait more than a couple days to see if the scoring reappears.

Being a pessimist in this case, I have my doubts that it's finally fixed but I'll keep my fingers crossed.

 

[P38X2]

Also, I tried removing the deflector but couldn't get a grip on it at all, nor do I think it was causing any problems.

 

[boosted3g]

Wow that does look like it was dragging on there. At least you know what the problem is and have a plan to fix it.

 

[gfreek]

Also, I tried removing the deflector but couldn't get a grip on it at all, nor do I think it was causing any problems

The auger assy has to be in a certain position for me to remove the deflector easily....PIA reaching in there.. Is there any type of warranty on this stove for this issue??

 

[rickwai]

Wow that does look like it was dragging on there. At least you know what the problem is and have a plan to fix it.

The feeder assembly is under warranty longer than electrical part of the warranty. Look in back of your manual. How old is the stove? There were slide plate issues when they changed to the new style feeder.

 

[P38X2]

The feeder assembly is under warranty longer than electrical part of the warranty. Look in back of your manual. How old is the stove? There were slide plate issues when they changed to the new style feeder.

The auger assy has to be in a certain position for me to remove the deflector easily....PIA reaching in there.. Is there any type of warranty on this stove for this issue??

The stove isn't even a year old. I wanted to take one last shot at fixing it myself before mentioning "warranty" to the dealer. They showed me another slide plate that had very similar marks but never mentioned that possibly being an issue. Strange no one else on the forum has had this problem.

Do you recall what the slide plate issues were?

I'll check later on today to see if the marks are returning. Still quiet though

 

[P38X2]

Wow that does look like it was dragging on there. At least you know what the problem is and have a plan to fix it.

Yep

 

[mikkeeh]

How do you go about removing the slide plate? FWIW: I noticed that the "deflector" part is listed as "no longer available"....at least for my P43. Might be a reason for that???

 

[P38X2]

How do you go about removing the slide plate? FWIW: I noticed that the "deflector" part is listed as "no longer available"....at least for my P43. Might be a reason for that???

It's possible that's the reason.

To remove the slide plate....start be emptying the hopper. Run it in test mode to clear the remaining pellets. Take the rear side panel off and, using the test mode, get the cam bearing off the actuator arm. Now, UNPLUG THE STOVE! Remove the fines box cover and vacuum/blow out any pellets and debris. Manually move the actuator arm to move the plate out of the box.....or, if it's bound up, tap it back from inside the hopper using a flat head screwdriver. Go back under and pop the slide plate up and off the actuator arm and slide it out.

 

[mikkeeh]

Cool...Thx for the info!

 

[P38X2]

Cool...Thx for the info!

No prob.

 

[P38X2]

Update on the repair...

No doubt in my mind that was the issue. The picture of the scored slide plate doesn't give a great perspective on how deep those gouges actually were. From day one this "new style" stove has been louder than my '04, auger noise wise. I just figured it was the just how it was. The auger motor is silent now, unless you stick your head behind there. For the last year it was struggling to operate the slide and hopefully hasn't had too much service time taken away from it. When the hopper is empty, the slide plate can now be easily wiggled, and as long as the bearing is off the arm, it slides easily.

For those Harman owners who think their auger motor is a bit "off" sounding, you may wanna check your slide plate for unusual wear. Check to see if there's a bit of side to side play in it and get the bearing off the arm and see if it slides properly.

If it doesn't, don't assume that smoothing the area that's scratching the top of the plate is the issue. Sight down BOTH long edges of the slide plate and see if it's straight. If not, carefully straighten it. Note the slide is 2 pieces of metal held by rivets, at least on the new style. You DO NOT wanna loosen that connection. I cant say for sure if my problem was due to the plate being slightly bent or it was from the interference of the metal parts alone. Maybe it was both. The point is, check both.

With the proper basic tools, this repair is easy and can quiet your stove considerably and allow your auger motor to have an easier time operating.

Remember, UNPLUG THE STOVE. ()