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How do I remove a broken ...
givemethebighammer - 23/1/03 at 09:13 PM

How do I remove a broken bolt from a sierra rear suspension arm.
One of the four bolts holding the drive shaft mounting back plate (top ones) broke as I tried to remove it. No amount of WD40 was going to free that corroded / seized baby up!!!.

Problem now is that I can't find a drill bit hard enough to drill the bugger out.

Is it easier to just go get another suspension arm from the breakers ?



[Edited on 23/1/03 by givemethebighammer]


bob - 23/1/03 at 10:17 PM

Cant remember how much room there is,but can you not get a grinder on it to remove rest of head.


givemethebighammer - 23/1/03 at 10:39 PM

Oh no, it's really buggered, the bolt came most of the way out before breaking off right at the base, so the broken bit is well and truely inside the suspension arm !!!

Why do they always do that ?


Mark Allanson - 23/1/03 at 10:45 PM

Get the mig out, fire a spot on the end of the broken bolt, let it cool for a few seconds and fire a spot ontop of that, build this up until you can hammer a M10 nut over the end of the mound of weld you have built up. fill the remaining cavity with weld (as hot as your mig will go), leave this cool for 10 mins, beat the living sh*t out of the end of the nut and then use an impact screwdriver with a 17mm socket on the end to remove the bolt. If the nut shears off, do it all again.

The heat and the violence frees all the corrosion from between the threads and usually it comes out first time - if it doesn't, buy a nissan micra and take up flower arranging


Mark Allanson - 23/1/03 at 10:53 PM

You got your reply in whilst I was writing mine, spark errosion seems to be your only answer now, rig a coil up to a piece of copper the right diameter, rig the coil to a door bell solenoid (50 Hz) on the negative side, and the copper electrode will eat away the bolt, you keep having the re-adjust the electrode to keep almost contact with the bolt, make sure you use an old coil, they tend to burn out after a while!


jollygreengiant - 23/1/03 at 10:59 PM

1st Law of Motor Mechanics States :-

If it can go wrong it will go wrong in the worst possible way, at the worst posible time, when you really do need it least of all. And then it will get worse.


Bolts are locktighted in from new. If its almost out and then broken, the chances are that it has picked up a thread & welded itself in. Pesonally I would centre punch the remnant, get a small sharp drill (2mm) & start drilling slowly & carefully down the middle. Then when through start enlargening the hole until I got to Just short of the threads and then use a Tap to recover the threads. (or get another one).


Enjoy. (& good luck)


kamikaze - 24/1/03 at 07:37 AM

The best way to weld a nut on is to use a washer...between the broken bolt and the nut...first you put the washer on/over the broken bolt and weld in the middle.
Then you weld the bolt on to the washer...
If you do like thist you will be able to get a better weld on the bolt... The washer protects the bolt from getting welded on to the susp. arm...and you can get a much better weld...
I hope you can understand what i mean, consider my bad english...

[Edited on 24/1/03 by kamikaze]

[Edited on 24/1/03 by kamikaze]


James - 24/1/03 at 05:38 PM

quote:
Originally posted by givemethebighammer
How do I remove a broken bolt from a sierra rear suspension arm.
One of the four bolts holding the drive shaft mounting back plate (top ones) broke as I tried to remove it. No amount of WD40 was going to free that corroded / seized baby up!!!.

Problem now is that I can't find a drill bit hard enough to drill the bugger out.

Is it easier to just go get another suspension arm from the breakers ?



[Edited on 23/1/03 by givemethebighammer]


I spent 6 hours yesterday under a scrappy 4x4 battling rusty bolts. In the end I gave up with some of the bolts. It was far easier to drop the whole sub-frame off:
6 bolts,
2 dampers, (cutting them is easy but wear goggles and keep ur mouth closed
Two rubber brake hoses (cut unless you *really* want them)
two handbrake cables (cut)

Once it's all off you can grind away anything else as it's easy access!

If you're plan is to use the suspension arms on your Locost chassis then I'd have though the above is still valid because once the sub-frame is off it's pretty easy to reach all the bolts.

HTH,

James

[Edited on 24/1/03 by James]


bob - 24/1/03 at 06:13 PM

I told you the easy way,you wasted six hours of your life mate.

The young, you cant tell them anything


James - 24/1/03 at 07:29 PM

quote:
Originally posted by bob
The young, you cant tell them anything

Apparently so as I have no recollection at all! Sorry!

Anyway, the axle/diff is still as one- I'll have to work out how to get it apart when I get back from snowboarding next week.

Quite good day yesterday as got the LSD, a micra rad/fan/water bottle, Micra peddle box and a Fiesta wheel with new tyre all for £110 which strikes me as a Barry Bargain!
For Surrey scrapyards anyway...

Cheers,

James


bob - 24/1/03 at 10:02 PM

If you got the whole rear end with calipers as well not a bad price for down our way.

By the way it was on the phone i said drop the whole unit,never mind its done now.


MattWatson - 25/1/03 at 11:52 PM

Another thing to try for nuts that are stuck on is to heat them up with an acetalene torch (propane won't work) untill they are RED HOT.

Then take cold water, and pour it on the bolt. This will cause the rust to crack (with the expansion and contraction) and will allow you to easily remove the bolt/nut.

This has worked wonders on a 1950 Truck that we were restoring, as it had sat out in a field for 30 years.


givemethebighammer - 26/1/03 at 03:07 PM

Thanks for all the advice, however after several hours of fruitless effort, I decided to go to local scrapyard and grab another one. Easy way out, but no sense in flogging a dead horse so to speak. Especially if a new horse costs next to nothing !!