It is my understanding that the manufacture (MOCO) must show that the oil is what caused a warranty problem to use that as a reason not to honor warranty. I think SEMA
fought for this.

 

Alright let me straighten yall out weight is weight it's not different between engine, fork/hydraulic, transmission/hydraulic, gear. the difference between engine and gear oil is detergents gear oil doesn't have any

 

And you are wrong. Gear oil and engine oil viscosity are not the same, number-for-number. Each uses its own scale.

 

Well, other than the fact that every point you made here is wrong, you were right on the money....

 

I'm not wrong on this. 75 is thicker than 20 period. the "W" (10w40) stands for winter. Viscosity is weight. The difference between motor oil and gear oil is detergents gear oil normally doesn't have any, because oil as a lubricant doesn't wear out. unlike a combustion engine that oil is used to clean the motor, a gear box just needs to be kept lubricated. you replace dirty oil not worn out oil. Viscosity is a measurement like oz lb inches feet miles BTU it doesn't change.

 

Remove the foot from your facial orifice. You're wrong.

http://www.bobistheoilguy.com/puttin...nto-viscosity/
Now do all of these viscosity grades seem easier to understand? Okay, maybe not yet, so Table 5, a viscosity equivalent chart, provides a comparative illustration of all of the grades shown in tables 1 through 4. For example, the chart indicates that an SAE 50 engine oil and an SAE 90 gear oil are the same viscosity. This might surprise you if you think that gear oil is always thicker than engine oil. However, as Table 5 shows, they are nearly equivalent.

http://www.bestlubeusa.com/gearlube.pdf
Gear Oil and Motor Oil Are Not the Same
Gear oil differs from motor oil. Most people assume that
SAE 90 gear oil is much thicker than SAE 40 or 50 motor
oil. However, they are the same viscosity.

http://en.wikipedia.org/wiki/Gear_oilAPI viscosity ratings for gear oils are not directly comparable with those for http://en.wikipedia.org/wiki/Motor_oil, and they are thinner than the figures suggest. For example, many modern gearboxes use a 75W90 gear oil, which is actually of equivalent viscosity to a 10W40 motor oil.

And just for laughs, oil can wear out, whether it is gear or engine oil. If the molecular chains get chopped up the viscosity changes, and the fluid may no longer perform as it should.

 

Dave, you`re wrong... Do a little research instead of believing old tribal knowledge, at least make some effort to check your information before you post.

Unless you have a sludge problem or an engine failure, there is no reason to flush out the oil tank. Just follow a reasonable oil change interval.

How about never...

 

I use a Royal purple 20w50 max cycle.with there filter.but i want to switch tranns an final drive.but dont know what to use.....i have a 08 heratige softail classic.deer53533@yahoo.com SCOTT! thank you!

 

After reading multiple responses on this topic I decided to do my own test. I have an 01 Road King that I have owned for about 3 years. I faithfully change oil every 3,000 miles and have used Syn3 in all three holes. The previous owner was surprised at the change in the way the engine sounded with the synthetic oil (he used petro based oil). In any case, being ready for an oil change I took out my Fluke infrared temperature probe, shined it on my front and back cylinders after some trips of varying lengths. Temperatures were showing an average of about 247 degrees. This time when changing the oil rather than Syn3, I moved to Red Line, using 20W 50 motorcycle oil, V twin Transmission Oil, and V Twin Primary Oil. This time I was surprised at the difference in sound. Even the exhaust changed tone. Once again I took out my temperature tester and pointed it at the front and back cylinders. The riding conditions were the same as before as far as distance and outside temperature. However, this time the Fluke tester showed an average temperature of about 227 degrees. A 20 degree drop by changing oil and using the proper formula in each area, primary, tranny, and engine. I plan on sticking with Red Line.

 

WolfeSynthetics=SPAMMER