I have B&M 250 blowers. I need to know what to look for, what to check. I pulled the blowers and they look good to me. Dont see any rub marks or anything. How much end play is acceptable? What kind of oil should be used? How much does it take? Do I fill to the top hole or just to the lower one? Here's a good one... How do the rear bearing get lubricated? I dont see any signs of an oil passage from the front to the rear. Is there anyone in the Detroit area that services them? Don't really think I need service yet but I really need to know! I love this stuff!

90 Weight oil same as gear oil.