Manufacturer just sent me a new box which they claim was 100% quality checked (see previous thread). The documents say this unit ran on the dyno at 7 Pc/M^s-2 compared to a standard of 10 Pc/M^s-2.
Does anyone know what units these are? I did some research and found that gearbox noise is...
Hello and Happy Thanksgiving to all. Thought I would give you an update. I have operated the box for about 10 hours after securing the output shaft bearing races with Loctite and decreasing the mounting distance of the output gear by 0.015". The box was much quieter but still had a high pitch...
Thanks Terry. Tip and/or face profile mods doesn't sound like anything I can do. I am beginning to think the howling I hear may be unavoidable with the poor quality gears Ariens is using these days. My old box didn't howl for 18 years but maybe the gears were much better? Still waiting for my...
Mike, please be more specific. Are you saying a 15 minute run on a dyno is meaningless? Can any dynamic test be a substitute for properly setting up the gears? Can any 15 minute dynamic test determine if gears are properly aligned or not? Thanks.
PS Hope to have my old box, which I believe is...
I talked with Ariens about the misaligned gears and how I was able to get dramatic improvement (at least under no load conditions) by decreasing the MD of the output gear. I asked them what they are doing to make sure their boxes are set up right. They told me they run them on a dyno for 15...
Purely qualitative, but as I posted above, I am expecting to say bye-bye to the howl. Before adjusting output gear MD, it has hard to turn the input shaft by hand because of binding on 10 of the 19 output gear teeth. Now, they turn as smoothly as you can imagine with a very good contact pattern...
Hey, I am a retired chemical engineer who just entered the fascinating world of gearbox design. I temporarily lost control of myself. You have to be a little off to enjoy watching Arrow Gear videos on YouTube!
The Ariens story is sad. I am sure that when this box was first designed in the early...
Mike, I assume you are making fun of me? Are you saying to set the endplay to factory spec and stop worrying about differential thermal expansion? After all we are talking about a mower, not a space ship! Terry got me thinking that the factory endplay spec was too loose. Guess I am getting a...
Terry, the factory spec for endplay is 0.003-0.008" for both shafts. However, the box came from the factory with 0.028" endplay on the vertical output shaft. When this was corrected, the box began to howl. Apparently, the excessive output shaft endplay allowed the misaligned gears to run...
Terry said
"As I mentioned previously, the .030 inch shaft end play seems way to large for your gearbox's tapered roller bearing sets. If your gearbox housing is diecast aluminum and your shafts are steel, then that shaft's axial clearance should be set close to zero at room temp, since the...
Mike and Terry,
Tore the box down and cleaned everything up. Other than the output shaft bearing races being loose, it didn't look too bad although it shouldn't with just a few hours. I did a couple contact patterns at 0.006 & 0.013" BL. Horizontal shaft input gear has 22 teeth and vertical...
Terry, I forgot to ask - why would Ariens specify 0.003-0.008" endplay when it should be close to zero? Do you think they are just allowing some extra play because the gears are not a high quality matched set?
The Loctite I mentioned was #609 or 620.
Thanks Terry. I have a dial indicator but not the other items. I may take the box to a local shop depending on what the contact pattern shows.
I disassembled the box last night. All of the red grease around the tapered bearings was black from what I assume to be Al particles. The bearing races...
Arrow gear company has a series of video clips on YouTube. This one deals with analyzing contact patterns:
http://www.youtube.com/watch?v=Zi9PBZCgw-0
I got the new box from Ariens. It has more endplay than spec but it is much better than the earlier ones. It is also much quieter.
My local...
Mike, check this out. Ariens shipped 3 bad gearboxes in a row. The original on my new mower deck, the replacement box for me and a 3rd box the dealer had just ordered for a customer in FL. My dealer asked Ariens to ascertain if the die cast was out of spec. Ariens said they were not going to...
Mike, unfortunately, I believe your assessment is exactly right. But, as they say, it is what it is. What can I do to get the best performance out of this gearbox? Use Prussian Blue to measure contact pattern?
I believe the biggest problem I may have is that the input & output shafts may not be...
Mike, your deduced set-up procedure is 100% correct as stated in the service manual. One interesting note: the drawing/set-up procedure in the service manual makes no reference to shims on either side of the top bearing on the output shaft. So, as you stated, the location (mounting distance) of...
