Stripped threads in gear box casing

[Willie]

As above, when refitting my DBM I have stripped the threads in the GB casing.
There seems like there is a bit of meat and I know that alloy is easy to drill, so can I drill this out and helicoil it?
I've been on the helicoil site and for an M10 thread it needs a 13/32" drill bit, which is about 10.6mm, does this sound correct?
It's been ages since I used these but always though the drill bit size was a good bit bigger. I know that you have to tap it after this too.

Any help would be welcome.

 

[Willie]

Anyone?
Dave, m0rk???
Hooch??

 

[m0rk]

0.3mm a side would seem a little low to 'grip' the thread

are you sure you can drill that in situ squarely? that's the trick I've always struggled with when doing anything with helicoils is getting the hole right

 

[Willie]

I'm going to give it to a garage to do as with a ramp it should be easy.
0.3mm doesn't seem alot but the tap will take a bit more too.
Not too sure about this but will get someone else to do it as don't have the tools or the ramps for it.

Cheers for the reply m0rk

 

[m0rk]

ahh of course, I forgot the tap

That'll be fine in that case.

absolute worst case they'll have to remove the box to get it drilled square

 

[Willie]

Yup thanks, it looks easy enough but as you say getting it straight the first time is very important. The guy I'm getting to do it is a proper mechanic who fixes things instead of being a fitter.

 

[m0rk]

you'll be fine then.... fitter will require a brand new gearbox

 

[Willie]

lol, hes an older guy of the old fix it regeme, not the modern fitter turned computer whizz kid type mechanics.
Flame suit on and ready, lol

 

[ibizacupra]

how the hell did you manage to strip the threads? on both bolts?

man, are you super strong or not got a "feel" for when things are not starting to screw in properly by hand or power tooling them in..

 

[stpete]

Junior Senior aka Popeye!!! LOL

 

[ibizacupra]

must have been the spinach and 3rd shredded wheat i reckon

 

[Markyboyt]

lol, hes an older guy of the old fix it regeme, not the modern fitter turned computer whizz kid type mechanics.
Flame suit on and ready, lol

Easy tiger, don't mock it til you've tried it.
Now wheres that flamethrower lol

 

[Willie]

Well it was a bit of a few things TBH.
ELSAWIN doesn't say how much torques to make this up to so I went with 17 ft-lbs with 90 degreee extra rotation. But 90 was about 30 too much.
And it wsn't that difficult TBH.

anyway, can this be helicoiled??

 

[stpete]

I would say what have you got to lose, can it get any worse?

 

[Markyboyt]

Well it was a bit of a few things TBH.
ELSAWIN doesn't say how much torques to make this up to so I went with 17 ft-lbs with 90 degreee extra rotation. But 90 was about 30 too much.
And it wsn't that difficult TBH.

anyway, can this be helicoiled??

Do they use stretch bolts on the gearbox?
Normal bolts only usually require a straight torque setting unless they are aluminium bolts which require also require the torque + angle approach

 

[DPJ]

Do they use stretch bolts on the gearbox?
.........

No.

Torque settings for the dogbone bolts have been on here for years.

 

[CupraMVR]

Its easy enough to remove the airbox / filter and maybe the battery remove the gearbox mount with a jack or axle stand under the gearbox to hole it up and drill it out.make sure you use thread lock on the new bolts and on the new helicoiled outta part that is screwed into the box

 

[Willie]

No I have found out that these are not stretch bolts.
I was at my parents house that doesn't have a internet link so had no reference to this site.

BTW I'm not a ham fisted idiot, I make up hydraulic fittinga almost every day, just a bit of misunderstanding about the stretch/non stretch bolt thing.

 

[ibizacupra]

no torque angle tightening applicable into aluminium/magnesium casings

 

[Willie]

Excellent, thanks Bill.
I have a Peugeot master technician sorting it for me Wednesday