Post by brucek on Oct 13, 2017 17:38:59 GMT 10
Got back home from a recent road trip knowing I had a cracked final drive cover to deal with, so I stripped it down to determine the extent of the carnage. Here's what I found:
All fairly std. here. Crack propagated by the stress raiser created by the sharp corner produced in the machining op. Why doesn't Ivan use a milling cutter with a radius ground on the edge for f--k sake? Something a first year Fitting & Machining apprentice would be told to do.
Self explanatory.
The remains of the cage from the double row angular contact bearing which used to support the pinion. This allowed the pinion to move about thus destroying itself and the crown wheel. This also explains the rough gear noise I was hearing and feeling under acceleration, particularly in 3rd gear (I was blaming the gearbox).
I also removed the swing arm to look at the possibility of carrying out some mods to better locate the F/D by using an extra two, closer fitting studs, I haven't made my mind up on that one yet. The current set up has 9.9mm studs going into 11.3mm holes - can't rely on that for location. If the stud nuts come loose all the reversal loads are being taken by the flanks of the machined channel (with it's 'stress raiser' corners) in the F/D cover. It can't do anything except crack. Not a good situation.
And now the swing arm.
Has anyone had this problem? And no, nothing's twisted, bent or broken except me.
Two things here, with the pinch bolt nipped up the axle is out of line with the hole on the opposite side as the pictures show and is about 2mm out of parallel with the swing arm pivot bearings. With the axle pushed right through and the pinch bolt nipped up the F/D mating face is NOT square to the axle but the axle does come in parallel to the pivot bearings. Clearly the threaded end is still not concentric to the clearance hole. I hate this stuff, I wish I hadn't looked. All this I reckon can only contribute to the final drive problems so many of us experience. Sometimes I think the 'ignorance is bliss' philosophy is best. Anyway, on with the job, all the bits for the final drive re-build arrived the other day, time to get on with it. The swing arm is still a problem to be dealt with. I think I'll leave the best till last.
All fairly std. here. Crack propagated by the stress raiser created by the sharp corner produced in the machining op. Why doesn't Ivan use a milling cutter with a radius ground on the edge for f--k sake? Something a first year Fitting & Machining apprentice would be told to do.
Self explanatory.
The remains of the cage from the double row angular contact bearing which used to support the pinion. This allowed the pinion to move about thus destroying itself and the crown wheel. This also explains the rough gear noise I was hearing and feeling under acceleration, particularly in 3rd gear (I was blaming the gearbox).
I also removed the swing arm to look at the possibility of carrying out some mods to better locate the F/D by using an extra two, closer fitting studs, I haven't made my mind up on that one yet. The current set up has 9.9mm studs going into 11.3mm holes - can't rely on that for location. If the stud nuts come loose all the reversal loads are being taken by the flanks of the machined channel (with it's 'stress raiser' corners) in the F/D cover. It can't do anything except crack. Not a good situation.
And now the swing arm.
Has anyone had this problem? And no, nothing's twisted, bent or broken except me.
Two things here, with the pinch bolt nipped up the axle is out of line with the hole on the opposite side as the pictures show and is about 2mm out of parallel with the swing arm pivot bearings. With the axle pushed right through and the pinch bolt nipped up the F/D mating face is NOT square to the axle but the axle does come in parallel to the pivot bearings. Clearly the threaded end is still not concentric to the clearance hole. I hate this stuff, I wish I hadn't looked. All this I reckon can only contribute to the final drive problems so many of us experience. Sometimes I think the 'ignorance is bliss' philosophy is best. Anyway, on with the job, all the bits for the final drive re-build arrived the other day, time to get on with it. The swing arm is still a problem to be dealt with. I think I'll leave the best till last.
