Broken Bolts in rear subframe sheared off... how to extract?

Hey you all, thank you for your patience and your insight...


.... my seemingly bad luck seems to persist, but I am stubborn and i love riding this bike...!

The two bolts that hold the cross bar for the givi rear trunk rack sheared off while on the BQE in nyc. Good times! luckily i didn't loose my new givi aluminum luggage....

HOWEVER, i have two sheared off bolts stuck in the rear subframe. see these beautiful pics....

I did a little research, and the best method seems to be using a tap and reverse threaded drill bits so extract the broken bolt... this seems feasible, except for the fact that the rear wheel seems to be in the way of my drill. And i have no place to work on the bike.

Question... is there any other method which could extract these two broken bolts? Or should I find a shop willing to lend a helping hand? (Not too many shops will find the time to deal with this....)

Let me know if there is another method I could use...

Thank you all wise GRiSO peeps,

r.

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Obviously, removing the rear wheel would be preferable, but if that's not an option, would a right-angle drill have enough clearance? I have a nice, compact Milwaukee I'd be happy to lend you, but I'm on the Left Coast.

Maybe this cheap HFT unit would do the trick.

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What about:

DEWALT 20V MAX Right Angle Drill, Cordless, Tool Only (DCD740B) [You must be registered and logged in to see this link.]

General Tools 89 Stainless Steel Automatic Center Punch with Adjustable Stroke [You must be registered and logged in to see this link.]

And

IRWIN Screw Extractor/ Drill Bit Set, 10-Piece (11119) [You must be registered and logged in to see this link.]

?

Sheesh. I’m going broke getting this Moto up and running....

Think I could pull this off with these tools?
A shop would cost about the same, yes? How long would this take a shop?

R

And does anyone know the size of these bolts and thread pitch? Going to order some killer string bolts on McMaster....

R

I'm by no means an expert, but I have fettled bikes outside on the street before, so I'm aware of the disadvantages. If you can organise all the tools you'll need for the job before, including a thermos of appropriate liquid, choose a fine, not too windy day, and preferably have an associate to stand by, look wise, take incriminating photos, and fend off distractions from curious passers by, you should be fine. I should think you would need clear access, so that means the wheel has to come off. To start the left hand drills, a punch & a 6lb hammer is useful to provide a dent in the centre of the screw. Once you get the hole in, I'd try an ezy out - they have been known to break off (whereupon a shop is really useful) so care is needed. The access with the wheel off is handy here. If the ezy out works as it's supposed to, all is golden. You'll just need a couple of new screws handy. It might be an idea to get some hints on the use & misuse of ezy outs from experts in the trade beforehand, so you have an idea of what to expect. Good luck.

An ez out... like this?

Or do you recommend something else?

Elitexion Screw Extractor Remover Set – 6 Pieces [You must be registered and logged in to see this link.]

Two things here:
1) Hand tools are cheaper and can usually get into tighter places. Don't spend money on things you won't use often.
2) What ever you buy, buy the best. A cheap threading tap or extractor, broken off in the bolt you're trying to remove, will cause much grief and added expense. The cheesy extractor set you linked is crap. I have a Snap-On set, and it's barely good enough.

That said, get a couple of left-handed drill bits and carefully follow the advice given above about making a centering divot to guide you. Patience will be rewarded. Oh, and invest in some quality penetrating fluid. Not that WD-40 crap. (No, I'm not opinionated. )

Have you looked under the seat & airbox? I think that bolt is 8mm X 1.25 if it went to the original spindle for tie down cord. If it is a 6mm or 5mm it will go into a clip/nut piece of crap.
Pull the airbox you can get to the other side on top.

Ezy-out was the original of this type of screw extractor. As has been noted above, there is a lot of garbage out these these days that looks the same, but is not built to do the job. Get hold of the best you can find - ask those who use this stuff for a living for recommendations. They've seen the lot.

GuzziSteve wrote:

Have you looked under the seat & airbox? I think that bolt is 8mm X 1.25 if it went to the original spindle for tie down cord. If it is a 6mm or 5mm it will go into a clip/nut piece of crap.
Pull the airbox you can get to the other side on top.

It seems to be the original spindle for the tie down cord, and it seems to be directly underneath the subframe tube. So I am guessing the top is not accessible as it is likely welded to the bottom of the subframe tube?

I'v had a few apart but can't remember if it has a head and is a through bolt. It should be just like the other 2 w/spindles on them. Parts book shows 4 bolts, must be threaded into frame then. May be an easier fix from on top cept for air box but they pop right out.

Nah, they're way aft of the airbox. 8x1.25mm M8 thread. They'll be a bastard to get out. Given your circumstances I'd take it to your local thread repair bloke.

Pete Roper wrote:

Nah, they're way aft of the airbox. 8x1.25mm M8 thread. They'll be a bastard to get out. Given your circumstances I'd take it to your local thread repair bloke.

how do i find a thread repair bloke???

r.

Well, I'm not in Queens but I'm sure Hamlin in Ct can do it.

You should be able to access the top of broken off bolt in the frame from the top, behind airbox then take off the wrap around tailpiece.
I'd drill small hole in center of it & put in self tapping screw, when it tightens up it should back the bolt out from underneath. Use some penetrating oil on it for ease.

whyrichard wrote:

Pete Roper wrote:

Nah, they're way aft of the airbox. 8x1.25mm M8 thread. They'll be a bastard to get out. Given your circumstances I'd take it to your local thread repair bloke.

how do i find a thread repair bloke???

r.

How about a google search for 'Thread repair' followed by your suburb?

Good penetrating fluid (Kroil, Rust Aide, PB Blaster, etc), vibration, and GENTLE heat are your friends. By gentle heat, I mean low enough that it is barely uncomfortable to the fingers. It's amazing what a little thermal expansion will do. Of course, make sure you don't melt any plastic bits. An electric heat gun, or even a hair dryer works well.

Vibration can be in the form of an impact tool, or hammer. Gentle raps on the end of the broken fastener can break the corrosion bonds and release things.

Good luck.

Pete Roper wrote:

whyrichard wrote:

Pete Roper wrote:

Nah, they're way aft of the airbox. 8x1.25mm M8 thread. They'll be a bastard to get out. Given your circumstances I'd take it to your local thread repair bloke.

how do i find a thread repair bloke???

r.

How about a google search for 'Thread repair' followed by your suburb?

no luck in nyc for "thread repair".... maybe a machine shop? a metal working shop?

r

How about asking Moto Guzzi Brooklyn, 215 Park Ave, Brooklyn, NY 11205?

If they can't help, they will know who probably can.

kiwi dave wrote:

How about asking Moto Guzzi Brooklyn, 215 Park Ave, Brooklyn, NY 11205?

If they can't help, they will know who probably can.

i was there already, they are a bit too commercial and swamped at this time of year to bother...

i'll try my local friendly old school auto mechanic...

thanks,
r

We (in Sydney) are fortunate, a bunch of guzzisti got together and rented a shed in an industrial complex to work on & store bikes. In the complex there's an auto mechanic, specialising in race cars, and other older stuff, a high end machine shop, and there was a business making roll cages - he's moved out out, but not very far & we know where he is. Great resources to have on hand & have proved very useful for the odd sheared bolt. They also know of lots of other resources in the area, including a mobile screw removal/repair service. They are out there, finding them is the catch.

It's a long shot, but have you tried just pushing a flat blade screw driver against the broken fastener and see if it will turn? Try simple things first. If there's any bolt still sticking out, try getting on it with a GOOD locking pliers and turning it out. Genuine Vise-Grips will do.

Stupid question because i have never done it

How hard to get the rear subframe off?

It's easy. Just use an angle grinder.





















....I'll get my hat.

If you can get to my garage in Harriman NY I can get those out for you.

#1 remove rear wheel
#2 Punch center of bolt
#3 reverse drill bit small
#4 reverse drill bit medium
#5 tap to clean up threads

In your original list of tool you showed an automatic centre punch. I've had success with this. Put on plenty of easing oil ( kroil is great ) Then go around the edge of the broken bolt ( just inside the tread ) with the auto centre punch at about a 45° angle ( obviously - in the unscrew direction ) .  The combination of the impact and the easing oil sometimes works.  It's a long shot, but might be worth a try.