Front sub frame bolt sheared

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
User avatar
s13b
E30 Zone Newbie
E30 Zone Newbie
Posts: 159
Joined: Tue May 25, 2010 11:00 pm

Sat May 09, 2015 11:56 pm

ARSE

Trying to get the car ready to put on a jig. Easy job, drop the front subframe... One of the bolts sheared despite plenty of wd40.
Now the subframe refuses to drop off the end of the bolt. Ive tried lever bars, heavy blunt persuasion and gravity.

Anyone got any bright ideas?


Cheers
Last edited by s13b on Sun May 10, 2015 12:08 am, edited 1 time in total.
User avatar
s13b
E30 Zone Newbie
E30 Zone Newbie
Posts: 159
Joined: Tue May 25, 2010 11:00 pm

Sat May 09, 2015 11:57 pm

also tried putting the other bolts back in and dropping the offending side first
Speedtouch
Old Skooler
Old Skooler
Posts: 14024
Joined: Tue Feb 14, 2006 11:00 pm
Location: Canterbury

Sun May 10, 2015 12:03 am

Use a belt sander or similar tool to grind down the bit of broken bolt that's stopping the subframe from being removed, then MIG weld a suitable sized nut onto the remaining stub - the heat should help release the thread.

Also, use Plus Gas or similar penetrating fluid - far better than wd40. :wink:
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
User avatar
s13b
E30 Zone Newbie
E30 Zone Newbie
Posts: 159
Joined: Tue May 25, 2010 11:00 pm

Sun May 10, 2015 12:07 am

Trouble is the bit of the bolt that is left is the the recessed part of the subrame so cant easily grind it or cut it.
Maybe a hacksaw blade will fit??

however, winding a nut on and welding it into place might work.

Thanks
jimmyspeed
E30 Zone Regular
E30 Zone Regular
Posts: 848
Joined: Sat Sep 08, 2007 11:00 pm
Location: riding a wagon wheel west

Sun May 10, 2015 12:46 am

Is the shear flat enough to drill out and use a reverse thread remover?
User avatar
treeman
E30 Zone Newbie
E30 Zone Newbie
Posts: 15
Joined: Fri Jan 30, 2015 11:00 pm
Location: Scottish Borders

Fri May 15, 2015 8:48 pm

Not sure if I'm understanding this right but seems similar to the following.

I've had one of the bolts holding the front control arm bush holder (magnifing glass one) shear. I removed it by drilling down the centre of the bolt then using a dremmel with a cylindrical grinding stone to grind out the bolt shaft, down to the threads and picking them out with a draper pick set. Takes a while but works without damaging things. Might work for you.
Post Reply