Harman P68 Slow Startup

That's an excellent idea - rule out the pellets as a possible cause, if suspect.

TT, did the replacement part include the pillow / carrier bearings (? right term) for the shaft / circled in the the attached pic?

Only ask because the condition looks suspiciously similar to the condition of the auger end bearings on the Francesca here when inspected back in Sept., ended up using a Moly product to rehab them (on my stove here) to quiet auger noise here. (Apologies in advance if this is off-base / does not apply.)

ETA: agree, the difference in length of the (2) plates w/ the same part # would be a concern here also.

 

The pillow bearing on the left remains the same original part. The one on the right (outside the fines box, barely visible in the pic) came new with the new pusher arm. It had to come that way because of the way the arm is assembled, the right pillow is permanently attached to it. When I first installed the new pusher arm, it was actually bound up a bit. When I tightened up the retention bolts, the arm didn't want to move anymore. I took it back off (twice) to inspect it and figure out what was causing it to bind. Turns out it was that right pillow. It wasn't seated exactly straight in the bracket, so every time time I would tighten things up, there was just enough pressure / resistance to make the arm not want to move. In the end I got it to sit perfectly straight and the arm moves freely ever since.

 

I also think the P68 slide plate is "out of spec" and currently thinking that is/was the major contributor here. In case I haven't said this before, the slow startup issue that I started this thread with is not new. This has been going on for a long time, and it just got to the point where I was pulling my hair out so I finally posted about it. I suspect the majority, if not all of the wear on that pusher arm happened a long time ago (years) and it was really only identified as the problem a couple weeks ago. It's a little bothersome that no Harman dealers I spoke to have ever seen this happen before, and I don't want to be in the same boat a season or two or three from now with the part continuously getting worn down and needing to be replaced.

 

That's what I was afraid of .. If the shaft was being 'racked', my first check would be the pillow bearings: rollers, bearings, and gears are typically a 'wear' part.

I don't think the stove guy removing the deflector plate did you any favors, I would think the purpose of that plate is to deflect fines/dust from the area it was designed to protect. That would be another area of scrutiny here - but you know your stove / you are the best judge of this.

Don't have a clue w/ the proper torque value would be for those bolts, but if < 15 inch/lbs. value - I have a 'specialty' ( 0 -15 in/lb ) 1/4" torque wrench here that I needed to do a transmission repair several years ago, you are welcome to borrow it for the duration of your repair - if wanted/needed, just PM me and we can make that happen.

 

I agree, I think you found the 'root cause' of the issue.

TT, do you have any dealer support?

It might be worth a call or visit to explain your findings, and seeing if the Engineering folks @ Harman have heard / are aware of this issue? (That fixed pillow bearing may be borked..)

 

Thank you CF, appreciate all the support. I have not brought this to the Harman dealer yet. I was wondering if anyone else here with a P68 or access to one wouldn't mind popping their slide plate out and getting a measurement on it? Trust me, I KNOW that is a LOT to ask because it's not much fun taking it out, but would be great to compare notes and would go along way toward confidence in this being the issue before I go to the dealer. Anyway, I would be very grateful. The Harman part number is 1-10-677121A and the only place I have found that gives the dimensions is on the stove parts unlimited website and they list it as 6 9/16" x 3 15/16" which is actually a misprint, because the slide plate from my P43 is really 5 9/16" x 2 15/16" so their listing is off by 1" in both directions...

Edit: The P68 is a 2008 and is out of warranty, so even if this is/was a manufacturing defect, I expect the dealer won't be very interested in it. I will talk to them anyway, and if it doesn't go anywhere, I will contact Harman directly and see if I can get them to express any interest.

 

meant to say the left pillow bearing may be borked, as the right (fixed) bearing is new / attached to the shaft, if I've read correctly.

It doesn't look too bad to remove / check / service that left bearing, casing cover plate is held on by two bolts?

* Given the plate difference / the amount of wear on the arm (which I suspect is almost exactly the difference in length between the P68 plate vs. the P43 plate), plus weight of pellets / force applied, I'm going to guess that shaft was being racked in that support bearing for awhile.. Just a thought.

 

can-do, but not until tomorrow.....dont forget, there's two slideplates in P68's......ultralight model and non-ultralight model...depending on year...I think yers is an UL model though

 

I have P61 and once in a while it makes a sound similar to what you describe, maybe less metallic though. I never really gave it much thought as when I looked it over I never found any issues. It's done it since new and I always chalked it up to the odd pellet jamming something and the Harman chewing it up.

Reading further on though I see you are finding more issues, so probably something mechanical that is causing your problem. Especially since you had the major wear on that one part.

 

I can hear pellets getting broken or ground up all the time but there's no regularity to it. Always could. But I didn't think he was talkin about the same thing.

 

Yeah, when I went back a read things over again, I agree that that what I hear is not what he is hearing. But the post is cast now. Bah.

 

Thanks LW, yes it is UL.

 

yea, I haven't seen it either, ttdberg....stupid question tho on the slow starting....do you have one of those old 5-hole burnpots in it? (5 holes right in front of the auger)

 

I was also looking at the "old" and "new" pusher arm assembly....maybe I am crazy, but they don't appear the same to me...the "horn" looks like its a different shape/angle.
Working tomorrow, I'll pull the slide plate out of the p68 and measure it, comparing it the the P38 plate.....see what the difference it, tho it should be none....
here's a thought tho...the lower side of the "C", is the part which throws the slide plate forward into the closed position, right? (trying to visualize it in my mind...lol)....so, if you plate were too long, the bearing may in fact wear it out, as its trying to push the plate into place when it's already crammed home

 

No, just the standard 5 rows of holes. Nothing near the auger.

 

They are the same part. The reason they look so dramatically different is the old one has worn so much over 7 seasons. It completely lost the horn. With the new arm in, it starts up and dist blower is on in 5 mins or less every time now and I'm getting heat from it like I haven't had in a long time. Yes you are right, when the wheel bearing is touching the short end of the arm, that is pushing the slide plate away from the fines box cover, toward the auger.

 

as promised:

The top slide plate is used, out of a P43, the lower plate is out of a new P68. The dims are 2-31/32" wide x 5-9/16" long. The same size.



here they are, end-to-end...left hand new, P68, right hand, P43

Also not the difference in these plates than your own.....the tips on both of these slide plates are beveled UP (you can kinda see it inthe top plate of the first pic), instead of the pointy one you have.....been that way awhile, but I cant recall when the change was made, although it was made AFTER the changeover to the UL feeder system.