How Many Apex were sold last year: Chain Case Problem

[rxrider]

A possible solution, when waiting for a recall or something from Yamaha, would be using 0.35 litre of synthetic engine oil instead of 0.25 litre of gear oil. Synthetic engine oil can take the heat better than gear oil, using a little more to increase the volume will help cooling the chaincase some. There will also be less friction using 0-40 engine oil. I'm doing this although there is no problems with the 03-05 chaincases. BTW my dealer recommends using engine oil in all newer chaincases. Just my .02 $

 

[ReX]

A possible solution, when waiting for a recall or something from Yamaha, would be using 0.35 litre of synthetic engine oil instead of 0.25 litre of gear oil. Synthetic engine oil can take the heat better than gear oil, using a little more to increase the volume will help cooling the chaincase some. There will also be less friction using 0-40 engine oil. I'm doing this although there is no problems with the 03-05 chaincases. BTW my dealer recommends using engine oil in all newer chaincases. Just my .02 $

I'm not sure I'd recommend this for a few reasons:

1. Yamaha would probably say you aren't using an appropriate chaincase oil and could refuse warranty.

2. I read a paper many years ago from GM when they were developing their "new" 1969 front wheel drive automatic transmissions. These used a chain to transmit power from the back of the torque converter to the gear case (basically they took a "standard" automatic transmission, split it in two behind the torque converter and spun the back end around facing the other direction and placed it beside the torque converter). Some things I recall (warning: my memory could be a little rusty...):
- When using a "silent" chain a quality gear oil produced the minimum wear rate.
- A silent chain and engine oil ran about the same temperature and produce more chain wear
- A silent chain and automatic transmission fluid produced the highest wear rate, but ran the coolest temperatures
- When using a HYVO chain any of the fluids produced reasonable wear rates under normal loads (well below breakage torque levels), but under high loads the gear oil produced less wear.
- For a HYVO chain under normal/low torque levels and moderate hp levels (200+), ATF was determined to be the best for overall performance (plus it didn't require a separate oiling system). The HYVO chain also wore at a significantly lower rate than a silent chain. They went with the HYVO chain and ATF.

The problem with #2 is the torque transmitted through their huge chain was much lower than what is transmitted through our chain. Under high torque levels, the thicker gear oil produced the least wear. The main problem with the 06 Apex cases seems not that the heat doesn't get to the case, but that the heat doesn't get out of the case. Based on this, I suspect running a high quality, synthetic gear oil might be the best for durability. Most important is probably running a gear oil that works well and doesn't break down at high temperatures (synthetic).

I've also done experiments over the years running synthetic gear oil, synthetic motor oil, ATF, and Polaris chain oil in some of my previous snowmobiles. My experiments were inconclusive. As long as I changed the fluid regularly metal building up on the magnet didn't seem to occur any faster or slower (ATF might have been very slightly worse). The only outright failure I had was with my 1997 Storm SE when running fully synthetic 10w40 where the chain snapped at close to 10,000 miles (at that many miles it might have gone with any of the fluids).

 

[rxrider]

Good point and info ReX

Everyone should use the oil Yamaha calls for if their sled is still under warranty.

Whatever oil used, it has to withstand the heat present without breaking down. It has not happend yet on my 03 (alu/alu) or 05 (alu/mag) chaincases yet. I change chains at 5000 miles because of the beating they get on our non groomed trail system. I guess I will not know if the oil I use is bad for them.