Hello all and thanks for the add to the forum. I'm a small engine mechanic and competition bbq cook. I just recently purchased a new rotary cutter and have about 40 hours on it now. In the book it says to use GL-4 hpypoid or better 80w-90 gear oil. I'm a avid believer in synthetic lubricants. Recently I read a study done by currie enterprises about why the high end racing rear ends had failed using synthetic gear oil and currie made a jig that measured the temperature of the actual gear teeth. They came to the conclusion that regular dino oil dissipated heat better out of the gears into the differential housing while the synthetic did not. Even though the synthetic gear oil is a little lower in temp, the gear itself was alot higher. With that being said I'm kind of at a crossroads here..... im contemplating running some mobil 1 SAE J2360 high dollar gear oil to deal with the extreme Texas heat and extended intervals. My shredder cuts worlds better @ 600pto rpm versus the regular 540pto rpm. The other day after a 40 acre pasture the gearboxes were so hot they almost sizzled my finger. I read that SAE J2360 gear oil is not reccomended for GL-4 applications because of the possibility of messing with syncronizers. I'm not worried about any of that. This thing has 3 gearboxes and one main divider box. I am hard on my equipment. I use it hard and run it hard. But I want to provide every bit of insurance I can to this $18k rotary cutter as far as thermal protection and shock loads from hitting random stumps, ant nests or whatever I run over. I read one key thing about running synthetic gear lube is better for seals since they run lower temps...... or is did Currie enterprises disprove that theory? Is there anything to gain by using this top end gear oil lubricant or should I just stick with regular old tried and true dino 80w-90?




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