Splitting 108 alloys - rounded/broken bolts advice (Hampshire/Berkshire)

tadekk

Member
 Hampshire
It’s not the first topic about 108 refurbishment and I have done few searches, but still not clear how to proceed.

I have got myself a set of slightly corroded 108 alloys. It seems they were refurbished before but without being splitted, so the bolts themselves were very tight.

For future reference, the method that ultimately worked for me was:
1) remove tyres
2) spray the bolts with penetrating fluid and leave for 30 minutes
3) stick an M8 spline bit in the bolt and hit it few times with a hammer to break off tread corrosion
4) use a heat gun to heat the outside of the rim around the bolt until the inside is too hot to touch
5) use an impact wrench with GOOD quality M8 spline bit (I used Facom)

Initially I didn't follow my own advice, and I ended up with one broken stud (too much torque) and one rounded off bolt (crap Sealey spline bit). So my questions are as follows:

- How to remove the stud? Should I even attempt to get a stud extractor (what type?) or leave it to professionals? If so, who in Berkshire/Hampshire area could remove it?

- As above, but for the rounded head, at work we have a machine shop with a pillar drill and apparently you can drill titanium with a carbide tip at low speed with plenty of cutting oil. Any other advice? What size extractor/drill bit to use on an M7 bolt?

- Once removed, I am happy to tap it (and all other holes) with an M7x1.0 tap, but should I do it before or after refurbishment?

- Maybe linked but when I take it to the refurbisher, should I give them the bolts to insert before the rim is coated to prevent the threads getting painted? If so, should they use the BBS bolts or generic M7 bolts to avoid getting my bolts painted (for the second time).

I plan to take them to City Wheels in Birmingham to take advantage of the £20/wheel offer. They said once split, they can do the 108s, but does anyone has any recommendations closer to my area around the price?

Thanks, and I hope this topic proves useful in the future :)

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After splitting over 20 sets of these i developed a " easy " method of removing the thread left in rim itself once the head had snapped .
I have posted a pic in the past but it will be a long way back .
You need a small angle grinder & using some form of protection to the actual rim itself simply grind 2 flat surfaces to the thread in order to get a small spanner on & turn out the thread from low down on the shaft .
Total pig of a job with possible pitfalls at every stage but seeing the refurbed parts bolted back together is always a great reward for the time & effort :thumbsup:
https://z4-forum.com/forum/viewtopic.php?t=70793
looking back id say these were my favourite combo
 
I have started grinding the flats already, good to know it has got a chance to work. Just need to find a 5mm spanner (I’m past 6mm already).
 
I can lend you a set of cheap M7 bolts to go in the holes when you send the barrels off for powder coating (I’m near Newbury).

After doing one set of 108s myself, I would advise getting any thread repairs done before powder coating, and preferably using a competent machine shop to drill and tap the holes for helicoils square to the rim. If you try doing it at home you can easily end up with the helicoiled holes on the piss and then when you try to put the bolts in the head will catch the nice new paint on the wheel centre.

Chris
 
When it comes to the powder coating, you won’t find anyone even close to Citywheels prices down south. For ref, the price of the set I did via citywheels was £20, plus £5 for split rim, plus £5 for chrome silver finish on the barrel (each).
 
rally-chris said:
I can lend you a set of cheap M7 bolts to go in the holes when you send the barrels off for powder coating (I’m near Newbury).

Thanks for the offer, I will take you up on it once the old bolts are sorted. Wouldn’t even attempt helicoiling myself, that’s why I’d rather avoid drilling out. I will try mole grips with heating next.

I’m hoping you’re happy with City Wheels, how does the finish hold up over time?
 
tadekk said:
I have started grinding the flats already, good to know it has got a chance to work. Just need to find a 5mm spanner (I’m past 6mm already).

If you cant get a spanner to fit see if you can get a set of mole grips onto the flats.
Put the mole grips on the end of the bolt and slip a bar in between the jaws of the mole grips and use this to turn them out.
I have seen this working with rounded bolts holding the brake discs on a bike wheel.
 
My favourite method is to TIG a nut or bolt to the broken bolt. Let it cool completely then wind it out with a ratchet.
This obviously turns the broken bolt into brand new bolt, but also has a secondary advantage - The extreme heat/cooling cycle expands and contracts the bolt and hole, loosening the bonded thread.

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Got both of them out in the end. The stripped one came off easy just with eazy-outs, without any damage to the treads. The stud I had to get drilled out and re-tapped. Once I clean off all the holes, I will test if it torques OK as-is or if it needs a helicoil.
 
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