MG Car Repair/Canít get the front wheel hub off
Good morning! I just acquired a 1979 MGB. It appears that the front right, outer wheel bearing is shot. I ordered a new bearing, spindle nut and pin. Problem is, I canít get the hub off to get to the spindle and put the new bearing on. I called and talked to a tech at Moss in California and he said I needed a hub puller. I rented one, hooked it up and still couldnít get the hub off. In the process of tightening the hub puller, it dug a hole into the tip of the spindle and damaged the threads where the locking nut goes. Can you help work me through this fix and tell me what Iím doing wrong? Does the hub supposed to come off? Thanks in advance! Steve Bouye
The inner bearing race of the outer bearing probably has "Spin Welded" itself to the axle. The MGB wheel bearing is designed to have a spacer between the inner bearing race of the inner bearing and the inner race of the outer bearing With shims to adjust the preload on the bearing. The axle nut is then locked down tight to clamp the two inner races solid to keep them square and solid as one unit.
This is a very good design and the front wheel bearings last a very long time, provided they are greased and adjusted for preload. Most domestic car mechanics have not seen this on other cars so when they service the wheel bearings they set it up wrong and cause this type of failure.
But at this point you just need to get it off to see how much damage has been done. At this point you need an oxy/acc torch to heat the inner race to get it to expand and then the wheel hub puller will pull it off. You must apply the torch in just one spot on the inner bearing race and do it in next to the actual bearings and quickly so that the majority of the heat is applied to the race and thus less it applied to the axle itself. Keep the flame tip small so as to apply the heat to a small area on the inner race. You want to see that small area of inner race get bright red and then quickly apply the puller. Don't try to heat the whole inner race because that transmits too much heat to the axle.
I have had a few domestic cars spin weld the bearing race to the axle to a point that I had to use a cutting torch to cut the race. That is difficult to do without damaging the axle itself and on an MG that is the whole spindle assembly. Your outer couple of threads on the axle can be corrected with a "Thread file". Most tool trucks have them "Snap-on", "Matco" etc.
Or worst case if the axle is damaged, Google your closest MG or British car specialist as they often will have used parts as nothing for an MG is trashed anymore. If you can't get a oxy/acc torch you can remove the whole spindle, king pin assembly off the car and take it to a shop that has a torch. Leave the caliper attached to the brake line and use a coat hanger to hang it so as not to hang by the brake line. Be careful and don't loose any of the spacers on the lower king pin mount.
I have marked your photo as to where to apply the torch.