10-25-2015, 09:06 PM
2100 rpms max if you are under load, 2300 rpms max no load. I try to stay at 2100 max rpm descending a hill with the jake brake on but if it were to momentarily go up to 2200 or 2300 with no load before you could get it back down below 2100 with the service brakes, it should not hurt it.
Jakes work most effectively when the engine is up in the 1800+ range on an 8V92 so I try to pick a gear where I can maintain my speed going down a hill with the engine at 1800-2100 rpm. On a steep hill that may mean 2nd gear which tops out at 40 mph at 2100 rpm. On an 8% grade I doubt you will be able to use anything higher than 2nd gear without having to excessively use the service brake.
Jakes work most effectively when the engine is up in the 1800+ range on an 8V92 so I try to pick a gear where I can maintain my speed going down a hill with the engine at 1800-2100 rpm. On a steep hill that may mean 2nd gear which tops out at 40 mph at 2100 rpm. On an 8% grade I doubt you will be able to use anything higher than 2nd gear without having to excessively use the service brake.