I've bought two used Mk2 hub assemblies to renew the bearings. On one hub, I can't losen the big lower bolt (24 mm hex head)! This screw turns, without getting undone:-( It looks like the inner tourett is rotating as well. How may I undo this screw? I quickly tried to insert a 3 mm key into the hole, but couldn't block the inner tourett... What is the way forward? Many thanks Marcel
This lower screw was completely corroded into the turret! There was no way to undo the screw. I cut the screw head down and hammered the bolt down afterwards, until the swivel bearing and the turret were free. Unfortunately, this turret is crap only...
That’s what that little hole is for. You can put a pin through there and it locates in the turret to stop it spinning. (You can see the hole in your first few photos)
Yeah, I tried to insert a 2.5 mm drift punch into this hole. Unfortunately it sheared off, without blocking the turret enough, to unscrew the corroded screw... It was just fu***** tight.
A 3 mm drill would have been a better solution... Picture from the other hub, which was nearly new:-)
Hhmmmm, these are MK2 lower swivel bearings, not MK3 ones... I'm going to write the correct bearing number a bit later on. I've choosen proper INA Schaeffler quality parts, instead of cheaper ones. Maybe this is only a thing inside my brain, but a least for this peace of mind then...;-) The upper swivel bearing is a specific NTN SNR bearing. But to change this upper one, you need some specific bushes/spacers to press the bearing in and out with an appropriate threaded bar. Some sketches will follow...
Upper bearing: FC40857 S02-SNR Lower bearing: BK4520A Lower bearing seal: 45x52x4 The lower bearing can be knocked out easily enough, but the upper will almost certainly take a hydraulic press. These have to be pushed through from the inside of the hub towards the outside as they sit on a lip. Mine took about 8 tonnes before they broke free, but they’re very easy to remove in this way. Sent from my iPhone using Tapatalk
