Cracked Front Hub


XS650 New Member
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Rapid City, SD
Hello everybody. I've been a lurker on the forums for a while but this is my first post.

Tonight I pressed out my wheel bearings in preparation for powder coating. The non-speedometer side of the front hub had a small ding in the flange where the bearing and oil seal seat. While pressing the bearing out, the flange developed a crack when the bearing tried to pass through the deformed part of the flange. :doh: Should have done some preheating or sanded out the ding first.

As far as I can tell, the area of the flange where the crack formed is not a structural component of the hub and simply serves as a seat for the oil seal. The actual part of the hub where the bearing seats is inboard of the crack and is cast with a greater flange thickness. I've outlined in red where the bearing seats as evident by the thicker flange. I'm hoping I can just have someone tig weld a bead over the crack to keep it from growing. What do you guys think? A front hub isn't something you want to fall apart when going down the interstate, but I'm having a hard time imaging this crack leading to a total hub failure.

Any advice?




Technically that crack could be ground out and welded up then finished off.

Personally, if it was mine, I would bin it. For a crack to develop there in the first place would lead me to ask if the part had fundemental casting flaws any way.

When pressing bearings I always warm the surrounding areas first where possible to aid removal. Replacement involves the bearings being in the fridge first.
Hmm by the time you pay to have the crack welded and machined back to round on the inside you could find a good used hub and feel better about it. The crack being T shaped is probably good as far as structure.
I agree with Gary, the structure for the bearing is still good.

But, you need to have it reshaped so no further damage when trying to install the new bearing and seal.

Must have take quite a whack.

So, is it worth having a machinist re-true it or source a better hub.

I'd be looking for a better hub.

my 2 cents. (canadian that is):D
Fuck it. Put it on the wall and get a new one. If it fails while riding and you die is it worth the small $$$ savings?

Don't be a cheap/lazy bastard. :)
Unless you know the alloy and temper of the aluminum, it's a crap shoot on if it would work. Not worth the risk IMHO. I've seen a pickup truck full of weld repaired aircraft aluminum parts crack right next to the weld because the material does not get normalized (stress relieved) by a heat treating process after the weld, which usually involves an annealing or partial annealing, along with bringing it back to whatever temper it is for service. Effective temperatures range fairly wide for these processes with existing alloy and construction, be it cast, forged, milled billet or whatever.
Shoot... as you said the crack is outside of the bearing load area... send it to me. I'll risk my life on riding it welded, no problem. Id have a chunk of copper machined to to correct diameter to use as a heat sink/backer, and weld it.