My 8 speed Alfine has done 4000 miles. It was serviced after 2500 miles by the shop with Shimano grease. Last week, I serviced it again – but I used Auto Transmission Fluid (ATF) as is commonly advised on forums. I then greased the bearings before putting it back together. Before I put it back together, I checked the cogs and there was no play. But after mounting the hub back on the bike and doing 3 commutes, I noticed that: * The gear change is super slick * The hub is silence when freewheeling and gears 5-8 are whisper quiet whilst pedalling. BUT… Gears 1 & 2 make a loud whirring noise (bordering on grinding) – especially when cadence is low – i.e. uphill (70-80rpm). Gears 3 & 4 make a quieter whir when the cadence is low, but this disappears when the cadence is 90+. I’ve checked and double-checked to make sure the nuts are not overtightened or too loose. Is it simply a case of ATF being thinner and less viscose than grease so not as good as silencing the hub or should I be worried about this noise?