20 replies to this topic

[Elwyn]

Thanks

Never heard of plusgas, but I'll go straight to google

I'm not a welder, so I've shied away from options that involve welding

[xrocketengineer]

 

 

I don't think there is enough 'meat' to helicoil the horizontal ones. You really need to persevere and get the remains of the bolt out of these. (this is where dropping the subframe come is as they are accessible from the other side).

 

 

 

It is possible to use a helicoil on the horizontal bolts. Here entry #11:

 

https://www.theminif...il#entry3336546

[GraemeC]

Possible - yes.  Advisable - not so sure!

I didn't want to recommend it as I don't know off hand how big that captive nut is and therefore how much wall thickness is left once its been drilled and tapped for the helicoil - a lot of these captive nuts on the Mini are only just big enough for their intended purpose.  It may never be a problem, but I wouldn't want to recommend it without seeing the size of the existing nut first.

 

Looking at your photos though it does seem that the hole in the frame itself is much larger than needed and the nut is large enough to straddle that, so should be OK.

Edited by GraemeC, 08 December 2020 - 10:23 AM.

[Elwyn]

Thanks all

Remove rear subframe Vs helicoil?
I'll try the helicoil first

If that fails, I'll remove the subframe

Seems a sensible sequence of events to follow

 

Any advice regarding drill bits for drilling out the bolts?

Centre punch, start small, get bigger, take my time etc

But what about the bits themselves?

I have a set of pretty standard drill bits that I'm guessing are going to struggle with this task

[nicklouse]

Not much metal in the weld nuts for an insert. Remove and replace weld nuts.

[xrocketengineer]

Thanks all

Remove rear subframe Vs helicoil?
I'll try the helicoil first

If that fails, I'll remove the subframe

Seems a sensible sequence of events to follow

 

Any advice regarding drill bits for drilling out the bolts?

Centre punch, start small, get bigger, take my time etc

But what about the bits themselves?

I have a set of pretty standard drill bits that I'm guessing are going to struggle with this task

 

That is what i did with mine. However I had a lot of penetrating oil and as I went bigger and bigger on drill bit size, I got off centre and caused some damage to the threads on the nut as the broken bolt spun in and fell inside the subframe. At that point there was some thread left on the nut but not enough to be safe. So, I tried the helicoil and it worked well.

If you are more careful and patient with the drilling than I was and use a lot of penetrating oil (not WD40), you might get lucky and manage to spin out (or in) the broken bolts.  

Edited by xrocketengineer, 08 December 2020 - 02:41 PM.