Our coffee roaster uses a gearbox, wormgear, to take a fast moving motor and reduce speed in a 40-1 ratio, while also increasing torc. Worm gears have much more frictional force internally than straight gearing, and their benefit is that they are very compact, yet at the same time a little louder. even if you specify the same gearbox as a previous model you have there is more than just a model number that should be matched.
We are now on our second Vortex gearbox in 6 months (where our previous Morse-Emerson lasted 15 years). What we have learned is that efficiency of the gearbox and output torc changes differently with different brands as they heat up. a worm gear has a lot of friction and heats up quickly. Vortex is made in China, and perhaps the gearbox industry is not thriving there. we are now awaiting a Grove Gear wormgear- supposedly awesome, and it keeps the same output torc at start and when hot, where as the Vortex loses something like 55% of its output torc as it heats.
We do keep a logbook of the roaster maintenance, and the entry for this gearbox is much more in depth than what is written above. Its been two weeks on the intermediary Vortex and we bled the oil (which was filthy with metal shavings), flushed, and weighed in new oil. The Vortex leaks from the sightglass, and drips from the expansion valve whenever it is running, so we are looking forward to swapping it out as soon as possible.