Morning gents. I recently grabbed a bud's Bear that he claimed had diff issues. The diff itself, despite the goop inside spins smoothly and freely. However the entire rear brake assembly is missing. I believe the part that is missing was once where a bearing was mounted on the right side to support the shaft, hence the wobble. I attached a pic to see if anyone can help. Also if anyone has a repair manual in pdf format, I would love a copy.

 

Yes, the brake backplate has wheel bearings for the RH side inside it. The splines in the crownwheel will have taken a pounding, as will the diff bearings. Why would anyone be stupid enough to leave it off?

 

I don't know why they did it brother, but it is my problem now. I don't plan to source all the parts for the rear brakes, but must have a bearing for the shaft to ride on. Can I order just the backplate (have a part number?) and bolt it all back together. Is it part number 16 in the link?


Yamaha ATV Parts 2003 BIG BEAR 4WD - YFM400FWR REAR WHEEL Diagram

 

The backing plate appears to be obsolete. You might try to ref the part number to a 400 Kodiak of maybe even a Bear Tracker ( 250 ) or another yamaha rear drum ATV. You will need the bearings, seals and othe componets to make it correct. You might try to find the backing plate used.

 

Well the journey begins. I will update this thread if and when I make progress.

 

I've just bust a backplate on a Honda 400Auto. The brakes were seized and the drum stuck so fast on the axle the puller broke the backplate as I tried pulling them both off together. Some idiot had welded the LH hub to the shaft, so removing the lot and pressing the drum/backplate off wasn't an option. Anyway, got a Honda 350 backplate complete with bearings and shoes for £36 from a breaker, problem solved. Incidentally the 400 had a different part number to the 350 backplate, but was the same.