If we assume two straight-weight conventional oils, same manufacturer and brand, the only difference is one is SAE50 and one is SAE60, what will be the difference in flow characteristics at 125 degrees Fahrenheit?
SAE50 vs. SAE60 Flow Characteristics At Temperature?
- Thread starter CCI
- Start date
At 125*F, not enough to worry about.
SAE 50 at (16cSt) flows quicker than SAE 60 at (21cSt) during start up temp of 104ºF or operating temp of 212ºF assuming the difference between the grades you might see this depending on the brand...
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You can use this graph to extrapolate to 60 grade and to 125 F. Not a huge difference, however, notice it is a log scale and the temps are in C. 125 F is 52 C.
Thank you, this is the info I was looking for.
The back story is I was working on a bike (5-speed Evo Harley) that the owner had put BelRay gear lube in. I've seen pretty impressive results from BelRay in terms of quieting things down, but this bike has an intermittently leaking main drive gear seal which is not going to be changed any time soon and the tacky/sticky gear lube was making quite a mess, which is especially rough on a rear drive belt.
That stuff doesn't wash off very easily at all. Not off bikes, not off clothing, it is seriously messy stuff.
Motor oil was originally spec'd for these transmissions, and I wondered what would happen if I put a straight-weight oil in this transmission. If nothing else it will be easier to clean the oil off the bike.
All I had on the shelf was 20w-50 Mobil1, 15-w40 Rotella, 10w-40 Mobil1, and some aftermarket SAE60 formulated for Harleys. I decided to try the SAE60 just for an experiment.
The shifting is a little louder clunk but smoother and more positive. The gear whine that was there with the BelRay is gone. The operating temperature of the transmission is about 125 to 150 when the head temp is about 220 after a 20 mile test ride.
And it completely quit leaking.
The back story is I was working on a bike (5-speed Evo Harley) that the owner had put BelRay gear lube in. I've seen pretty impressive results from BelRay in terms of quieting things down, but this bike has an intermittently leaking main drive gear seal which is not going to be changed any time soon and the tacky/sticky gear lube was making quite a mess, which is especially rough on a rear drive belt.
That stuff doesn't wash off very easily at all. Not off bikes, not off clothing, it is seriously messy stuff.
Motor oil was originally spec'd for these transmissions, and I wondered what would happen if I put a straight-weight oil in this transmission. If nothing else it will be easier to clean the oil off the bike.
All I had on the shelf was 20w-50 Mobil1, 15-w40 Rotella, 10w-40 Mobil1, and some aftermarket SAE60 formulated for Harleys. I decided to try the SAE60 just for an experiment.
The shifting is a little louder clunk but smoother and more positive. The gear whine that was there with the BelRay is gone. The operating temperature of the transmission is about 125 to 150 when the head temp is about 220 after a 20 mile test ride.
And it completely quit leaking.
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