Very hot 750 FD

[BossMaverick]

As some might recall, I recently installed a used 750 FD. I've only been able to put about 200 miles on it. Today, I averaged 70-75 mph for about 50 miles. I checked the temp after the ride and I could only keep my hand on the FD for about 3 seconds before I had to pull it off due to the heat. My previous 1100 FD only got warm and occasionally borderline hot. I used the correct amount of Amsoil 80w90 gear lube when I did the 750 install. When I drained the old fluid out of the 750 FD before the swap it was super black with tons of shavings on the drain plug. I felt at the time that it was probably because the fluid hadn't been changed in forever, but now I'm thinking otherwise.

I'm assuming I got a bad 750 FD unless you guys think otherwise

[planedick]

Probably

I agree, you got a bad FD. Sounds like the PO didn't use the right gear lube and destroyed the gears. Th gear lube has to be hypoid rated.

[BossMaverick]

Go figure, there isn't a super cheap 750 FD on ebay right now either, they are all $50 plus with shipping charges.

[bikerphil]

Did you overtighten that 22MM nut when you put in the new washer? JAT

[BossMaverick]

Did you overtighten that 22MM nut when you put in the new washer? JAT

Pretty sure I didn't, at least I don't think so. I tightened it to 75 ft lbs. I didn't even use a impact gun to take it apart for fear of notching the bearings or drive teeth.

The seller at least is willing to refund the purchase price (without shipping of course) without having me send it back.

[Ivan]

You might pull the plug and have a look at the gear teeth if you can. If they are still nice and shiny, it could be just a bearing, which might be salvaged from your stock FD.

JAT

[BossMaverick]

I bought an 850 FD off ebay for a more reasonable price. I would've normally tried experimenting with bearings and such but I'm trying to get the bike ready for a high mileage trip and I don't want to be worrying the whole way about a limping along on a bad FD.