I spent several weeks (here and there, not nonstop) ... Completely rebuilding and renovating the rear suspension. New upper and lower control arms, tie rods, shocks, springs, derusting and repainting rear subframe, etc. Finished everything torqued up at ride height on Sunday with 4 wheel tracking booked at ATS for Monday.

I present car. After an hour, unshaven school leaver mechanic asks me to look at a problem. He has managed to turn the tooth of the OS eccentric washer that sits in the groove out of the groove and stripped the threads so hardly able to do more than finger tight. 

Anyway, I surprise myself at not blowing my top. Young lad using a two foot breaker bar and a two foot torque wrench, no wonder it ended badly. As usual in most of these situations: poor training and a poor attitude. SOP for today.

Anyway, to the point. I drove the car home, ordered a new bolt kit. I called the ATS manager and he was reasonable offering to use my bolts to replace and then align. Then alarmed me with the idea of taking a heater coil to the bolt (why, when it's the nut? And what would happen to the rubber bush with heat conducting bolt to metal sleeve to rubber?). Surely a simple nut splitter is all that's needed worst case (the nut is not even seized ).

So now lack of confidence in the so called professionals means I am pondering replacing the bolts myself (again), if I can get the nut off. My idea being to lift on to axle stands, take the weight off the axles slightly with jacks under each, punch out the old (but still new) bolt with an impact ended screwdriver which will follow immediately behind the bolt to act as a temporary bolt to keep the control arm in place. And then do the reverse with the new bolt pushing out the screwdriver. Then raising the axles to ride height (MK2.5 estate 184mm) and torquing to 90 nm as specified.

Does this procedure make sense, or am I missing something?

Not something I've done myself, but the Idea sounds alright to me. Perhaps someone like @TomsFocus would have a better idea if that would work.

Hmm, seems like extra risk for no real gain to me.  Not keen on the idea of pushing a bolt through under tension.  High chance of damaging the threads if it's even slightly off-centre.  I'd just do it properly, car on stands, wheels off, swap the bolt without any tension on the arm.

Thanks Tom, that's my worry - the tension. Plus the idea of using heat to remove a spinning nut (opposite of being seized). Nut splitter is surely right if back levering and hand ratchet doesn't work. Techs here seem to think the answer to all problems is force rather than thought!

If the garage who goofed up does it, then it may be on the rear wheels and just hoisted, unless I tell them (will they listen?). They tell me a more experienced person will do it this time. Should I just let them sort it (assuming they know what they're doing or care)? 

Or should I do it myself: i.e. jack then stands, wheels off, axles allowed to drop (reducing spring tension), just enough jack tension on each axle to stop the springs falling out. Then change the bolts, jack axles up to ride height and then torque.

Think I will speak to them and ask them what how they intend to handle. If not happy, I will put the bolts in myself.

In a garage situation I'd just cut the spinning nut off with an air tool in 30 seconds.  Can't see why heat is needed.  I've had mixed results with nut splitters personally but they are the better option on a driveway.

I'd like to say leave it to the garage to fix their mess...but after relenting and having some work done 'professionally' on my property this week, I'm left with more faults than I started with so back to my old adage - if I want a job properly, I'll have to do it myself!

Tom, you are so right. If you really want a job done properly then you have to DIY.

Spoke with the garage today. Said I would not accept the use of heat in view of potential for damaging the new bushing. He agreed. Told him worst case saw the bolt but don't mess the new paintwork (ha!). I think the free spinning nut will come off fairly easily, but techs become ham fisted when power is at hand). Seems ok with that.

I asked him if the tech was experienced. He said he would be trained (didn't seem to understand that training is only half the education, also forgetting the useless tech who created the problem was supposedly "trained".

He said the car would be on the hoist. Told him about the danger of tension of the springs. Penny dropped and he said they would put on a lift which allows axles to be dropped. I said ok, but then take the rear wheels off to ease the tension / strain on bushes.

So will take the car to them, talk though the work with the tech and manager, write it down, then they can do it.

Was told that (only there for alignment originally, wouldn't go otherwise) each tech supplies their own tools, so will supply them a torque wrench set correctly, the new bolt kit, and add the copper grease (smooth part) and threadlocker (threaded part) to the bolt myself. Surely fool proof (😉)

Having messed up what should have been a simple 4 wheel alignment, I have no faith in them.

If I don't get agreement to proceed as above, will DIY and find another place to do the alignment and warn people off that particular ATS.

Competence and a professional attitude are becoming ever rarer ...

NOTE

all suspension bushes must only ever be tightened when the suspension is in the mid laden position....

so never do them up when dangling on a two poster ramp - if you do - when the car is on the ground and some load is in - all the bushes will be part twisted - then you hit a big dip at speed and you'll have torn all your new / reused formerly good bushes to bits

Thanks, yes, aware all suspension arm bushing bolts only to be torqued at "ride height". For a Mk2.5 Focus estate that's 184mm between subframe and lower control arm. I cut a wooden spacer for this very purpose.

For ATS redoing the one cambered bolt they messed up, they did the 4 wheel alignment immediately after which is where they would have torqued those two cambered bolts, (car sitting on wheels at ride height).

Incidentally I noticed on current and previous alignment data that before I did the work rear alignment was -2.7, after 1.9 (so more centred even without getting an alignment) and is now 0.70 after alignment.

Can't say the difference in the way the car feels is huge (front wheels were aligned last year) but the car does feel more "poised" at speed.

I redid the whole rear suspension as originally only intending the arms but then found bottom coil of OS rear coil spring had snapped off so went the whole hog with OS and NS.