Rear beam bracket-6mm bolts.

[Mattbee]

My rear beam brackets (or push rods as BMW call them) are rusty and holey so I’ve got some replacements on the way.
I thought I’d be a good Boy Scout and be prepared for the swap by getting all the fixings loosened off.
The main 22mm nuts were fine, good clean of the threads and lots of Plus Gas, worked them back and forward and got them off, cleaned up and refitted.
Cleaned up the 2 6mm Allen head bolts either side, used a needle to clean out the Allen sockets and again lots of Plus Gas.
First one came out nicely once I had tapped the Allen socket firmly home and given it a steady, firm pull. The one next to it and the other two are a different story!
All 3 show signs of having been previously rounded out and the 6mm was baggy in them. Didn’t even try loading it. Tried tapping a Torx in but that span on gentle pressure on all 3. What next? I’ve ordered a set of Unwin bolt extractors but I’m worried that the tapered base of them will mean they won’t work. I’m extra worried about the two next to the fuel tank as access is a bi*** and I don’t want to use heat there...
No access to welding equipment and they are both so crusty and weak I’m concerned about driving it anywhere...

 

[t-tony]

Don't worry about the taper on the Irwin sockets that is how they work.

Tony.

 

[Mattbee]

I meant on the bolts. They flare out towards the base. (Should have said that rather than taper, sorry!)
Just worried that would stop the Unwin biting properly...

 

[spurs fan in a coupe]

It’s awkward in there, no room to get the hammer in, but I’ve done it lots of times with those Irwin sockets, they are so good

 

[Mattbee]

That’s good to hear. I’m hoping a few days of repeated Plus Gas will help, along with a prayer or two!

 

[t-tony]

You will get them out Matt. Stick with it mate.

Tony

 

[Steve Medlock]

Worth (eventually!) replacing them with normal hex head bolts. (If you want to stay 'BMW' there is a BMW bolt of the same dimensions and grade)

 

[Mattbee]

Had a little go today. Not great. The bolts seem to be between sizes for the Inwin extractors. One size slips on with a bit of resistance but then just spins, the next size down just seems too smsll and I’ve not been able to get enough ‘swing’ with a hammer to tap them on. It’s worse on the drivers side as there’s just so little room...
Beginning to wonder if cutting the heads off is a good idea although that still leaves me with the threaded sections to deal with after the heads are off...

 

[Steve Medlock]

Mine were bad. I wouldn't be too hasty about cutting the heads off.

 

[Althulas]

Do you have enough room to attach an extension onto the Irwin socket so you can have room to welly the extension?

Do you have a welder that you could weld a nut onto the bolt head?

Last resort would be to buy some quality drills to tap the bolt with a left handed thread M5 or M6 and a left handed threaded M5 or M6 bolt, start with the smallest drill and gently drill into the bolt and repeat until you can tap it and then use the left handed bolt to screw in then hopefully unwind the old bolt out.

Or you could slowly drill the bolt out to 6.5 to 6.8mm and then use a normal M8 tap to cut the remains out to the existing thread but would require to be quite accurate with your drilling hence the other two previous options are less risk.

Anyone else have any other ideas?

 

[Mattbee]

No welder so that option is out.
Will persist with the Unwin extractors next attempt but the two by the fuel tank really don’t allow much room to getan extension on.
The back of the car is quite low at the moment so I’m going toget it up higher on the axle stands to give me a little more room.
I do have a 90deg drill adapter and a load of cobalt bits, as well as a dremel with a flex drive and also a multi-tool thing with carbide blades, hence wondering about the drill/cut method. When I’ve done similar before (on my old Landrover) I drilled gradually bigger holes through the bolt until the head basically fell off end then have found that the remains are often quite easy to remove once the tension of the head against the surface is gone.
It’s mainly the lack of decent access that concerns me as I’m not 100% that there’s enough room to get nice and straight behind it with a drill bit.

 

[Woodsta888]

Aren't you meant to drill holes to the correct size for the internal extractors, preferably with a left handed drill bit. That should give you the bite you need. Is it the multi spline extractors you have?

 

[t-tony]

It depends on the type of extractor you are using, there different ones. I have a set of Blue-Point ones which are parallel sides with very hard, sharp splines down their sides. You drill a certain size hole for the size of stud/bolt you wish to remove, then knock the extractor into the hole and next you slide down a Hexagonal piece which fits the splines and then you can turn this with a spanner. Beauty of these is that you don't swell the broken fastener as you do with a tapered extractor.

This type,

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Tony.

 

[Woodsta888]

Yeah I think the OP mentions Irwin extractors hence why I said as I have all of them, and if they are the internal multi-splined ones you gotta drill a hole first.

 

[Mattbee]

To confirm, it’s the external type of extractors I’m trying to use.
Have never really had much success with the internal type and givenhow little access I’ve got in this case the last thing I want to be doing is trying to drill/grind out a broken extractor!

 

[Mattbee]

Just thought I’d close this off, in case anyone else had the same drama in the future.
5 hours spent today but have successfully got all the bolts out and the brackets changed. Had to drill the 3 stuck ones out as I just couldn’t get the extractors to work. So used a 90deg angle adapter on my drill and worked up from 3mm to 6mm with lots of cutting fluid. Then used a carbide blade in my multi tool and cut a big slot in the heads. Hammered a flat driver socket into the cut and got them to turn, with a bit of back and forwards, all 3 came out.
I then ran an M8 tap down the threads, cleaned them out andswapped over the brackets, fitting with new bolts. Still hex head but with straight outer surface instead of the flared originals. Have filled the Allen sockets with thick grease to prevent corrosion in there.
Beam bushes aren’t totally shot but will need doing at some point, will probably give the Zedshed a call later in the year.
Happy and relived now, booked in for tracking and new tyres on Friday am then off for MOT in the afternoon!

 

[Stevo7682]

Just came across this thread and was reading down the posts glad to hear your perseverance got you there in the end .

Stephen.

 

[hard top]

As posted above, iis good to read that you got the job done ....