MAC motor is whining at me..

Up until just a few days ago it ran perfectly, with little noise and no problems whatsoever. Now it still runs, but there is a pretty loud whining noise under load. The wheel spins, the clutch seems to be OK, no clicking or anything... not sure what's going on. Might a loose or wet hall connection cause this? A bad bearing maybe?
Any advice appreciated.
I don't ride it hard or anything, its my commuter bike and I live in Florida-no big hills here.

Does the whining change as you change the speed.
I'd suspect bad bearing(s).

It does rise and fall with the motor speed. When the motor isn't being used it's a silent smooth ride. Guess I'll be pulling the motor apart this weekend to check bearings....

Sounds like the gears to me. Likely most of the noise can be removed by taking the grease that slung off onto the case, and re applying it to the gear ring on the case.

Most likely not real damage to the gears, they just pushed off the lube.

Easy to open the case, un do the screws on one side, then remove the nut on the axle on the other side.

I've been looking at teardowns and, I have to say, this looks lots easier than my BMC was..even with fiddly spacer washers. Will do on my day off (Tues-Wed) and report back if lube helps or not. Luckily I have Mobilgrease 28 in a drawer around here somewhere. Thanks for the advice, all!

How much of that Mobilgrease 28 do you have?
I've been looking everywhere for it for my BMC V1 motor.

Easy to get at Amazon, if you're in the States..
http://www.amazon.com/Mobil-Mobilgrease-Aviation-Grease-MIL-PRF-81322/dp/B00G3BTV5A
Probably at any aviation shop in Canada.

wyvernwaddell said:

Easy to get at Amazon, if you're in the States..
http://www.amazon.com/Mobil-Mobilgrease-Aviation-Grease-MIL-PRF-81322/dp/B00G3BTV5A
Probably at any aviation shop in Canada.

Click to expand...

Oh I have tried, most have minumum order dollar amounts.
I ended up buying a high temp grease from Canadian Tire. $7 for a tube.

How much are you putting into the motor?

Can't really be sure until I open her up and look, but I can't imagine it'll be more than 8 or 10 grams worth. I don't want to put so much on that it slops everywhere...just enough to lube the gears.

Well opened her up and took a look and found......water! Seems the last time it rained, I must not have had the bike properly covered. The lube was pretty gunked up, of course. So I wiped it all down, dried everything thoroughly, cleaned anything that looked funky (smoothed a couple of inside case imperfections while I was in there) Mobilgreased everything and sealed both sides with just a tiny bit of silicone when I put it back together. It is now MUCH quieter. The gears and clutch looked fine-no problems there. The bearings are fine and move smoothly, so they got a little lube too, just for shits and grins.
Thanks all for the advice and help, it is much appreciated.

wyvernwaddell said:

Well opened her up and took a look and found......water! Seems the last time it rained, I must not have had the bike properly covered.

Click to expand...

Quite possibly - but you may also be getting zinged by water or the humid FL air getting sucked into the motor when it cools - a pressure differential phenomenon discussed by Justin some years back. Water/air enters though the bearings and wiring channel even if the cover is completely sealed - you can't fight a vacuum.

Since it's impossible to prevent this water/air ingress with any amount of sealing, an effective solution is to let the water out by venting the hub. I run BMCs (essentially MACs with different cases) and had a similar water problem. I drilled a 1/16 in hole in the cover lined up with the inside of edge of the case so water would be forced out when the wheel spins. End of water problems - even running the hubs submerged to the axles.



Here's a graphic demonstration of the 'sucking water' effect...

[youtube]xwKbpsOmHjE[/youtube]

Cables bring water in too.
Saw it on one one Justin's Grin Tech videos.

Ive heard the Macs have a problem with sticking clutches. Tip the bike over and gently turn the wheel in both directions if you can feel the motor cogging in both directions your clutch is not working. Pay to check this before pulling things apart. 1000w has had some experience with this problem.