Machine is a MANITOU M50-4, year 2008 with DANA-SPICER axle with wet brakes, type 112-204.
Until first service on axle was done everything was fine (they didn't use the machine 10-12 per day at the beggining). After first service on 80 working hours (first change according to MANITOU 50-100 hours, then every 500 hours) the problems occured - they also started to work 10-12 day per hard work. We replaced the original oil with original MANITOU immersed brakes oil, specification is 85W90 (API GL4 - MIL L-2105).
After changing the oil customer called us at 150 working hours that there is some strange noise coming from axle when he brakes. The problem is even more obivious when the axle gets hot or they really work hard. And you can also hear the sound only when the truck is almost at stop, lets say from 7-5 km/h per hour to full stop 0 km/h. When you brake at high speed you can't hear the noise or is there very very seldom.

I have a the same problem on the other machine with CLARK HURT axle, type 112-284. There the problem occured at 1.600 hours and they work hard also 10-12 hours per day. We changed the brake discs inside the axle put new oil inside as mentioned above, added the additive for immerse brakes (for no noise) but the problem occured again after 500 hours.

I am lost, any1 can help me ?