Ive managed to strip the thread to one of the bolts that hold the rear crud catcher (bottom bolt). The top two bolts are holding it in place but it does wag around a bit more than I'd like so I'm going to see if I can repair it somehow. (No I don't want to take it off altogether) The first thing that springs to mind (no pun intended) was a Helicoil insert but I've never used them before and I've no idea of the thread size. Any other ham fisted beggars managed to do the same thing and subsequently repaired it? Any solutions other than Helicoil? All suggestions welcome (other than "Don't tighten it so much in future!")
Got a colleague at work who constantly over tightens screws. I can always tell which repairs are his because I have to get a larger diameter self-tapper and force it in.
Remove it all together , always worry's me as the bolts go into Alloy, not a great idea over a long period of time.
I had the exact same bolt position lose its alloy thread. I drilled it out and put a stainless helicoil in. Its easy enough to get to with a drill once the wheel is off. Remember to go in only to the depth of the thread so mark your drill bit with a bit of tape or something.
Others are available, but I like helicoil. I've seen one with a top had design of insert and a special drill. This limits the drill depth and creates the top hat void to a allow a flush insertion. Where are you? I've got the kit at Heathrow and I'll spare you the time to do the repair here (for the price of a few pints afterwards).
Same bolt broke off on mine too, cross-threaded and broke before it got to the correct depth. Alloy is a pain in the rear for cross threading at the slightest notice. Helicoil or the other one (that Aircon is referring to) is Time-Sert. Have used helicoils before and they are dead easy to use if you have access for the drill and can get it straight, got a pair of them holding the ball joint in place on my Mini at present.
AirCon Thanks for the offer but I'm 'oop North'. Thanks for suggestions everybody. I'm going to try a Helicoil kit. Anyone know the thread size of the existing bolt?
measure width ways across the outside of the threads with a ruler or vernier if you have one (or a nut if you know the size of it) will be either 5 or 6mm I should think. Don't worry about using a helicoil, when in industry and putting threads into aluminium we used to put helicoils in at the start if the screws were going to be loosened more than once. Never had one fail once fitted.
I've done this too and still have the new bolt somewhere to fit. Price was horrendous ( about £7 i think) for the new bolt. When you see the bholt you will understand whty it snaps so easily. I have done about 3000 miles since including a trip to Germany with it held on by the top bolts only and with no issues.
Phew its a relief to know that! I'm doing the National Road Rally this weekend so I don't have time to fix it before I go. I've used a cable tie as a temporary support until I get home.
Don't know the hole but check it's not longer than the bolt. Measure the hole depth with something thin then measure the bolt. If the hole is 30mm deep but the bolt is 25mm long then buy a 30mm bolt. That trick got me out the crap before.
The thread part of the bolt is much smaller diameter than the rest of the bolt. I will try and find my spare in the morning and measure it up.
Cheers, unfortunately the bolt dropped out so I don't have it available to measure myself. Not sure if it's the same size as the top bolts
The thread section is an M6 1.00mm thread and the thread is 10mm long. The shoulder section is M10 and 22mm long. The part number is 77211211B and the bolt costs a stupid £7.40 incl VAT.
Personally i think it would be better to replace with a decent quality 32mm M6 1.00mm bolt and put a plastic spacer in for the shoulder part.
To start with just get any longer M6 1.0 bolt and see if there is any thread down there to play with.
I have had the threads strip on this bolt as well I replaced the crud catcher with a carbon one and got a longer M6 bolt and spacer to insert for the crud catcher, the bolt hole in the swinging arm is open so the longer bolt went all the way through and I got a 10mm nut on the top side. easy to do and very secure, never had any bother with it and it has been removed several times to adjust the chain with no problem
