Whining sound........

[Polaris2007 4]

So My C121 has a pretty noticible whining sound that comes from the transmission when in high range reverse. In high range & any forward gear it is there, but you really have to listen for it. My other 'horses don't make this sound. I realize that a whining gearbox means worn gears and/or bearings, so I'll be tearing this one down after the snow season, to rebuild the tranny. I'm wondering if anyone else has an 8-speed that exhibits this symptom? I'm trying to decide if I can wait till snow season is over(it's my snowblowing machine), or if I should toss in the 4-speed from my 607 and use that tranny for the rest of the season. Thoughts?

[Don1977 604]

I can't say it's not the bearings. I had a bearing that would squeal when I turn sharp.

The gears are straight cut and they will whine when they get some wear on them. It's nothing to worry about if it's gear whine. My C-120 has a little gear whine.

[Kelly 1,029]

Hate to ask but did you check the fluid? full, clean?

[stevasaurus 22,863]

You will lose the low range option if you switch trannys and this is your blowing machine.

Ask yourself these questions...how long has the whine been there? Is it getting worse?

I only have a short driveway and sidewalk to clean, I would probably try to get by, you may not have that. A neat trick we used to use in the old service station to listen for a bad lifter, is to take a long screwdriver and use it like a stethoscope. Put the horse on blocks and running in gear. Put one end of the screwdriver next to your ear and the other end at various points around the bearings and touch the case. You should be able to isolate a bad bearing with this technique. BE CAREFUL. :banghead:

[rmaynard 15,598]

If you have a warm place to do it, I would drain the fluid. Milky looking oil has water in it and can cause the gears to whine. As said earlier, low oil can be a cause as well.

If you drain the oil, try to strain it through a piece of screen and look for metal. If you don't see a huge amount, I would try flushing it and refilling with 80/90 or 85/140 gear oil and try it again. If the whining persists, the old "Stevasaurus stethoscope" (screwdriver to the ear) is an excellent way of pinpointing where the problem is.

If draining the oil reveals a large amount of metal, I would hesitate using it so as to prevent more extensive damage.