richierich Posted March 14, 2013 Report Share Posted March 14, 2013 Hi I'm a TC virgin so be gentle....just picked up an 07 270 Rev 3. Quick check list of consumables compiled (bearings, pads, lubes, etcetera...) and parts overnighted from one of my favourite main dealers. On setting up the swingarm to press out the u/s pivot bearings I noticed a crack full width of the drive side needle bearing knuckle. Didn't take much pressing out; both bearings pretty much fell out with a gentle push. Crack then closed up and was barely visible. No other significant damage or bends visible anywhere else on the swingarm. Has anyone else come across this before? I have considered prepping the crack, tig welding and reaming the knuckle out to tolerance again to refit the bearings but I think the wall thickness is not sufficient to make such a repair structurally reliable. The bike has certainly been used for purpose but does not display any hard use or big hits for its age so I'm inclined to find this failure a bit out of character. That said, I'm no expert and eagerly wait to be stood corrected :0) Quote Link to comment Share on other sites More sharing options...
copemech Posted March 15, 2013 Report Share Posted March 15, 2013 Pics? Quote Link to comment Share on other sites More sharing options...
pindie Posted March 15, 2013 Report Share Posted March 15, 2013 Sounds nasty but I reckon your "knuckle reaming" will be the best option as you won't get this fixed under warranty. Quote Link to comment Share on other sites More sharing options...
tankygsy Posted March 15, 2013 Report Share Posted March 15, 2013 (edited) Without seeing a picture - my initial thought would be to 'v' out the crack, weld it up with mutiple passes, then ream it out say 2mm larger and fit a permantly locktited steel threaded insert machined to the bearing o.d. Edited March 15, 2013 by tankygsy Quote Link to comment Share on other sites More sharing options...
richierich Posted March 15, 2013 Author Report Share Posted March 15, 2013 Here is a pic of the swingarm back in situ with the new bearings fitted. Crack is clearly visible and has gone all the way through the bearing housing. I should have taken a pic while dismantled..apologies. The wall thickness is mighty thin. Didnt measure but estimate about 3 - 3.5mm. I dont reckon there's enough meat to bush it. Quite an unusual failure? Looks like I'll be adding a used Rev 3 swingarm to my wish list on the bay. Anyone know if all years are all compatible? I know there were changes during the 9 year production run of the Rev models but I'm not too fussy as long as it fits and works. Quote Link to comment Share on other sites More sharing options...
technowaldo Posted March 15, 2013 Report Share Posted March 15, 2013 take the needle roller back out of the affected side .put a pair of vicegrips on it to shut the crack and run a weld over the outside and it will be as good as new Quote Link to comment Share on other sites More sharing options...
0007 Posted March 15, 2013 Report Share Posted March 15, 2013 That's a very unusual place for a crack to occur, doesn't look to be related to stress from riding It may have happened when the bearing was pressed into it so I would make sure your interference fit is right I had a cracked swingarm welded a long time ago and the crack came right back, I think you need to completely remove the crack or at least make sure the material is completely fused inside and out Probably need to talk to someone who is more than just a welder Quote Link to comment Share on other sites More sharing options...
copemech Posted March 16, 2013 Report Share Posted March 16, 2013 I understand what 0007 is saying, but I would not put that much effort into it either as technowaldo says. To have the bore re- machined would cost more than the breakers swingarm. You need to find a good ali welder, and if in doubt I would try contacting any(or more than one) local welding supply shop, as I hope you may have them. They could likely point you in the right direction to a local who knows his stuff and knock out that job in minutes. Then just monitor the thing afterwards and toss it if need be. I recently found a great local welder this way, charged me a tenner for similar small job! Fantastic! Quote Link to comment Share on other sites More sharing options...
richierich Posted March 16, 2013 Author Report Share Posted March 16, 2013 Cheers for the input Chaps. Think I'll try that easy fix route first; find a local master tig welder and see what he can do for not a lot. The cause and the position of the crack is a head scratcher, though. Still on the look out for a replacement arm so if there are any years which anyone knows will not fit, please share your much valued knowledge :0) Quote Link to comment Share on other sites More sharing options...
tankygsy Posted March 16, 2013 Report Share Posted March 16, 2013 (edited) After seeing the pic and the thin wall thickness of the tube I would simply simply run a hacksaw through the crack, v it out tig weld it up, file it flat and bend a piece of flat ally around it and weld that to it to strengthen it up a bit / adding some extra wall thickness. Looking at it I'm not at all surprised its cracked, it's very thin and the loadings in that area will be high from torsional stresses. It won't take long for fatigue to creep in over time. I'm trained in tig welding and an engineer by trade, so that's how I'd do it - but I wouldn't have to pay someone to do it as I have all the tools so it wouldnt cost me anything to fix. if uou have a mate with a tig he'll fix it no problem for a minimal fee. You might find a cheap swing arm else where but if you plan on keeping the bike then a repair will be stronger than new swingarm in the long run. In fact I'd probably do both sides cause the other is bound to go soon too. Edited March 16, 2013 by tankygsy Quote Link to comment Share on other sites More sharing options...
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