Sheared suspension bolt
 

Hi All
Following my recent post about suspension knocking on my 1969 1800 I discovered one of the rear support arm bushes was badly worn. During the work the rear bolt that screws into the chassis rail sheared off leaving a gnarled bit of bolt about 3 to 4mm long - so not much to grab hold of. (Photos attached)
We (me and a very capable neighbour) tried welding a nut onto the remains but couldn't get enough penetration with the restricted angle of the welder in such a tight space so the weld broke with minimal effort.
I removed the rubber bung in the chassis rail and pushed a camera inside and I can see the piece of bolt in its captive nut and it looks surprisingly clean and corrosion free. I've also managed to get some WD40 sprayed in but it's a bit blind. I've got some PlusGas on order too. Wondered if anyone had any other clever ideas we could try before drilling it and using easy-outs.
Thanks
Simon

It isn't particularly clear to me (cos I don't own the model) where that bolt goes and on which part of the car it is. Is this front suspension or rear? (It might not matter of course!)

I'm not sure if the following advice is appropriate but in similar situations I've removed the head of bolts by grinding away carefully so that the tension in the bolt is gone - allowing the remaining shank to be turned (with easy outs in some cases).

Hi Army
It's difficult looking at a random bit of car you're not familiar with.
It's rear suspension, forward of the rear wheel. Bolt goes through bracket, support arm with rubber bush and into chassis rail. Location is just before the chassis loops upwards over rear axle to the rear. I've attached another photo that may clarify things. Thanks.

Ah, the joys of working on old cars!

Are you sure that's a captive nut?

From memory (I replaced all my arms & installed polybushes a few years back on my 1970 133) the nut on the ‘other’ side is not captive – try hammering a decent socket on see if you can wind the nut off (the nut should be ½ inch). Get a bit of heat on the nut first and with luck you’ll get the damn thing off quite easily.

Part number is 955569 for the bolt and 950356 for the bolt. Brookhouse (as always): https://www.classicvolvoparts.co.uk/...Bolts_Nuts_ETC.

ALWAYS use new nuts and bolts on suspension when re-fitting as the old ones may look fine, but you never know what horrors many decades of stress may have done to the internals. Replaced all mine with new from Brookhouse so I know they are the correct nuts and bolts for the job.

Now I see!

I think it is worth checking like Faust says it could well be a nut on the other end - it is on my PV

Uplander;

It's always recommended, to have a look at the exploded assembly diagram...(GCP site, see Page 250 for B20 1800, excerpt added below) and the Torque Rod (Item 12, the one with larger bushing on Axle tube end) does indeed have a longer bolt, which goes through that spacer in the frame and Nut on the other side...so it looks to me like remains of Bolt are broken off in that (unthreaded) spacer...I'd have a look at the other side of the frame...it looks like you should find a nut there, which once removed, should allow that bolt stub to be drifted out...
http://www.sw-em.com/Ideas_298.jpg

Good Hunting!

Thanks for your thoughts. However, the 'other' side of the sheared off section is in a chassis box section as per attached diagram. It may not strictly be a captive nut, just welded as part of the inside chassis side wall but there is no access to it. I was only able to see it by feeding an inspection camera into the box section.

Ul...;

OK understood...so I guess you're talking about Item 19, Support Arm...which has no nut, but indeed threads into a captive threaded insert in the frame...and the massive torque applied to back out the rusted part of bolt, which was protruding through that thread was enough to lock the bolt in threads and shear it (this also tells me that WD, mostly useless anyway, but none of it was where it needed to be, lubing that threaded interface).

I can't recall immediately, but is there access to drill?...at this point, removal of the stub is going to be a major operation and pain...I can suggest that it might be easier to turn the stub in after heating it red hot with a gas torch to loosen rust in threads, then drilling or somehow getting something on it, with which to get it to turn, (really) applying a proper penetrant (also on threads from inside frame box), and trying to get it to move...none of which is news to you or your neighbor probably...

Good Hunting!

Thanks Ron. Yes, your description is correct.
There is access for a right angled drill. It does seem the best way is to carefully drill a hole in the bolt and attempt to remove it with an easy-out.
Simon

Instead of, and/or as well as using PlusGas, use diesel over a couple of days or ideally weeks, adding a few drops every day, as diesel penetrates much better than PlusGas or similar products.

Changing the suspension bushes is a tricky job because of the rusted nuts and bolts, took me several weeks when I did mine 2 years ago; mostly waiting for PlusGas to work. I didn't know the diesel trick then...

From your pictures, I think the best approach will be drill into the sheared off bolt with a metal drill pit. If you drill the hole slightly off centre, this may help turn the remaining bolt pit in the thread (after you've applied plenty of the above to loosen the rust).

My 5 cents... good luck