Can the balancer gear wear out????

[don_vanecek]

OK, I am baffled, in turning the crankshaft 360 degrees, most of the time there is significant wiggle in the balancer gear and the gear off the crank-it appears from my Haynes called the driven gear.  In other words you can wiggle the two gears and that I think is my tick tick.  Now as you turn the crank around, at some spots they will go solid and you can't really wiggle them at all. 

SOO.....can these to gears just get worn out and hence all  this clearance at times and the associated noise???? 

Come on one of you old pro's what's going on here???

[don_vanecek]

bump

[Rick G]

It possible, its also possible that the gears were manufactured out of tolerance  of with an incorrect heat treat ! Contact one of the guys on the forum with disassembled engines and get a differant set . (Sunburned AZ)  This is a first time problem for me , although balance gears coming loose is not. Could be that a loose  retaining nut caused the problem too!

[don_vanecek]

Well, I put it back together, maybe if I can't get a few hundred out of it yet this year I'll look into this again this winter, runs great, but no one's going to want :( to buy it with that sound.  Oh, well, 46,000 miles, lots of trips-many that I have posted on this forum, one trip I got published in the VJMC magazine. 

I have feeling that the driven gear that just has a slot, not a key, has developed too much slop, BUT perhaps it's something else.

[jefferson]

I am wondering if the key that you made for it wasn't quite tight enough or the nut isn't tightened enough. Then again something could have been damaged when it was running before with too much play. It is kind of weird that it tightens up and gets loose on rotation. When you say loose is it axially or radially?

Jeff

[don_vanecek]

Jeff, I think the key on the balancer nut is fine, I think the free play is on the other gear, as you turn the crank around there will be a spot (I didn't see if within the full 360 if there are multiple spots-I think it maybe when a cylinder goes on compression) where you cannot turn-by this I mean my fingers on the outside of the gears and turning the gear for free play back and forth.  There is no in and out movement.  visually, the gears appear to match perfectly.

Sort of makes no sense to me, I'm only guessing as the engine runs there is a load and then no load and so that slack then makes a noise as this repeats over and over?

Any ideas?     

[Rikugun]

I'd agree it seems likely the 2 loose gears may be causing the ticking noise. Depending on how long the condition existed perhaps even a new key can't address wear on all the associated parts. I've been scratching my head over the "loose then tight" during rotation thing too.

The balancer gear is dampened with dowels, springs and a boss that integrates the gear to the shaft. I wonder if uneven wear of these components has the gear held centered during part of the rotation then loose during the rest of the rotation. The weights on the shaft and crank pulses may naturally impart a rocking motion that causes the wear but is only seen on higher mileage engines.