Had removed my suspension belly pan to check for fuel hose kinks and upon putting it
back in place, was tightening the 10mm bolts that hold the belly pan to the aux.
support and heard a sickening crack of the bolt shearing off. So, passenger side bolt is installed fine but the driver's side is broken off in the hole! I'm guessing that I shouldn't do any driving until I get the piece of bolt removed? Is that line of thinking correct? I think this repair is going to be a pain in the ass....
Bolts look pretty corroded but it was totally my fault.....maybe I'll get lucky with a left hand drill bit! Not the way I wanted to start the weekend off.

Do not drive it with that "pan" removed.

Sears carries the small bolt extractors.
Even my local FLAPS has a set or two of various types.

May be a stupid question but...why not drive without that "pan"?
Mike

Pan protects brakes and steering.

Zach

It is also a structural member for the whole steering rack.
Just look at the size of bolts that holds it in.
If it was just a "cover" it would have the same pan-heads that the engine tins have.

OK thanks...I'll reinstall mine asap.
Mike

Yep, those 2 10x20mm bolts that strap onto the crossmember have like 65lb. torque
value on them! I wouldn't want that thing moving around while driving, even if it's an auxiliary support. I'm hoping it won't be too awful to remove the broken bolt....we'll see!
I appreciate the tips Stu....

Weld a nut to the end of the broken bolt and then unscrew it. Fill the inside of the nut with your weld. When you use a torque wrench you should always reach the specified value in increments. At 65lbs, I would start at 50 then increase 5lbs at a time. An m8 bolt that gets 16 lbs gets torqued at 12, then 14, then 16. Rusty bolts can easily break way under torque value! Bolts and threaded holes should be clean and dry for proper torqueing

I have driven for a while without that pan, no issues.

The larger bolts need to be put in and torqued to hold the rear cross member, agreed.

The pan has no structural value in any way at all, most of them are rusted to paper thin on the easy coast.

It offers protection, but stupid driving cannot be helped with a thin piece of metal.

It took awhile to drill the pilot hole but I got the broken bolt out very quickly with a
screw extractor......it didn't have much real torque on it. Time to get some good new bolts.....

You need to double check the torque spec on those bolts.
IIRC It should be ~35-40 pounds, not 65.

Did you mean 65 Newton Meters? Thats still on the heavy side but closer to the range of an M10 bolt.

Zach

See you used a screw extractor. Good choice

Welding a nut on the end of the broken stud may have only seized the threaded end more if it broke off flush to the pan.

Somewhere here I thought someone was driving without the pan and road debris hit the brake MS?

I POR15'd (I have no problems with the stuff) my pan and got a new seal from Mikey.

Good job in getting it out.

Well, it's a bit confusing looking at the Haynes manual....you have "Floorpan/body" listed as 34 ft lb. then "Auxiliary support/body" at 65 ft lb and "Floorpan/auxiliary support
at 11 ft lb.
I was told 65 ft lb. when I asked here before.....I guess I'm still confused about what it really is. Anyone else want to chime in on what torque value is correct? I've bought new bolts but not installed them yet......
It seems to me that it would be Auxiliary support/body.....the bolts definitely attach to the metal that ties onto the Auxiliary support (carrier) that the steering rack mounts to.
Anyone else have thoughts on what is right for torque on these bolts?

Edit: actually, looking at the PET diagrams, maybe the 65 ft. lb is for the 12 x 80mm bolts that fasten the auxiliary support beam to the body?

Screw extractor worked very well. I don't weld and it looked like it would be very easy to get weld on the metal of the auxiliary support bracket. The bolt was broken off down inside the hole so it wasn't sticking up at all. I didn't realize that Mikey made a seal for that pan....I could use one.

65 is way too high. 34 on m10 and 11 on the m8 shorties

i see plenty of 914 that come in looking like they haven't had a pan or the m10 bolts for decades with no sign of problem movement. perhaps fat sticky tires may show flex there but those cars typically are completely assembled

Thanks Sean, now I know why I broke that bolt off!!

Torque specs are listed online and are specific for the diameter of the bolt, not the application. So in general, most bolts on our cars will line up with the widely published torque specs for these bolt sizes.

I have mine off currently so I took a long look at it last nite and I would be surprised if it were structural. Yes, 2 of the 4 bolts are large but the "bolt hole tabs" don't look like they would carry much shear force at all. I'll still run with one as protection, though.

Thanks Rich, I didn't know that. This is what makes 914World so great for non experienced wrench turners like myself. Now, back to

Regarding my statement earlier about the pan being "structural".
I didnt mean that the pan itself was part of the structure, just "dont drive with it removed" UNLESS you put the bolts back in.....

Which in the OP's CASE would have been impossible since he had a sheared bolt in one of the holes.