Shimano chain set crank bolt rounded off!
Right, up date! And thank you for ideas above.
Tried tweaking the other right up and epoxy gluing in the Allen key in round one – no joy
Tried hammering in a torx bit – no joy
So next was the extractor, drilled down the bolt, head might be soft but shaft took out two bits, bored out extractor hole, screwed in extractor, tightened up then shaft sheared.
So now have an extractor shaft stuck in the bolt, the mole grips we have here just slip on them, even when seriously over tightened, have tried filing flats on the shaft but this is very hard metal that appears to polish the files!
Ideas at the mo are get some files for hardened metals and bigger mole grips. Any ideas much appreciated.Posted 4 years ago
A couple of suggestions if you still have some extractor to grapple. Soak the offending area in Plus Gas for a while available from motor factors and the like. Then try again or apply heat with a blow torch. This heat application will do the job but may cause discolouration. If you can’t get hold of the extractor you are probably going to have to drill through from the other side and knock the extractor back out, then drill the bolt out completely.Posted 4 years ago
There was an slx crank on the classifieds for £30 the other day 😉dvatcmarkMember
Mine did the same. I carefully hack sawed through the bolt by poisitioning the crank so I could get a junior hack saw blade down the slot. . It turned out I only needed to get about 2/3rds of the way through before it gave enough to be turned by a flat bladed screw driver.Posted 4 years ago
Update time.Posted 4 years ago
Bought, ‘freeze your nuts off’ , a new ‘super’ penetrating oil, new vice grips (big ones) and a diamond file.
Then filed the stuck extractor shaft to put two flats on it, sprayed bolt with super penetrating oil, left it, sprayed with the freeze, put new vice grips on and turned extractor – hoping it would undo bolt and all – extractor sheared but this time as a jagged mess too low to get grips on! : (
Thought about it, was getting ready to saw through the axle, taking out the whole chain set and one side of bearings. Teenage son talked me around to give it another chance. Have now bought more drill bits, more extractors and going to have ago from the other end but have metal saw handy (and eye on the slx cranks on here) to cut the bastard off!
Keep the other bolt in tightened up.Posted 4 years ago
Try tapping around the crank with a mallet a few times then penetrating oil. Also hammer the bolt from both ends with a screwdriver or similar.Even if it doesn’t loosen it up it will make you feel better.My mate tried everything and didn’t want to damage his XT crankset.
Got his dad to do it in the end by drilling through the bolt till it shattered bit by bit-Wear goggles!
Good luck and persevere.
The daily update! James has pointed out tool expenditure and certainly time invested is close or exceeding the cost of cranks. Position we are in now, rounded-out (back) crank pinch bolt stuck in with extractor stuck in it, sheared off level with the bottom of the allen head. Have now drilled a hole throught the bolt from the bottom to the extractor, the drill will not touch it and it won’t punch out. Have been tempted to drill out the bolt completely (taking out the threads the bolt tie into) from underneath and then either helicoil /time sert new threads for a new pinch bolt. There was no way to grip the head, so some filing in side the Allen head to try reproduce some edges and then finding a tight Allen key and have epoxied this in. I am going to leave it to cure overnight, then plus gas, hammering etc and have ago in the morning.
Has to come off as I experimented with a chain device (i was more jumpy a year or two ago, want to keep my wheels on the ground now) but it upsets the chainline in top x3 gears badly. Needs to come off and get the chain sorted.
Thanks for all of the replies, some really useful approaches here.Posted 4 years ago
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