Thread: Snapped off roof rail bolt. Time to check your factory rails?

---Chapter One---

I was doing my occasional check of the tightness of the bolts on my Rhino Pioneer platform a few weeks back when I noticed a bit of play on the rear right hand side. On closer inspection it was clear that the roof rail was a bit loose at the rear.

After prying off the little plastic cap that covers the roof-rail bolt holes, and applying a Torx head driver to the bolt underneath I discovered that it was a decapitated bolt. "Oh Oh", I thought. Does that mean I have to extract a broken bolt shaft?

Off comes the roof rack, and I get to work removing the other two bolts holding down the rail, and yes, unfortunately the bolt has sheared off level with the top of the captive nut.

Always looking for an excuse for a trip to Bunnings, I headed off with the sheared off bolt head and returned shortly after with an Ezi-out that I thought would do the trick.

I slammed a fully charged battery into the base of the drill like a commando slamming a full magazine into an M-16 (well not really but it sounds good), and drilled a nice neat pilot hole into the broken shank. Carefully inserting the Ezi-out I twisted it slowly and carefully counter clockwise, feeling the torque, being careful not to overdo it, now just applying a little more torque, still not moving, now just a little more - carefully applying just the right amount for the Ezi-out to snap off cleanly with just a little shard poking out the top pf the work piece, and about 10mm of Ezi-out left inside the bolt. Oops. I've really buggered that up now, haven't I?

Time for reflection. In fact time to pack up and go inside for dinner. Its getting dark and time to acknowledge that you now have a bigger problem than you started with because Ezi-outs are made of hardened steel and you just can't go and drill them out.




---Chapter Two--

Gosh the Internet is a wonderful resource isn't it? There's been plenty of people in my predicament before. Snapping off Ezi-outs is a well established tradition. Lots of people have been here and done that - what far fewer people have done it seems is get the bloody things out. Lots of theories - little practical help. Some of the ideas include shattering it with a hammer and punch. Grinding it out with a Dremel, welding a nut onto the bolt (when it does't have an Ezi-out in it), taking it to a specialist with an EDM machine (whatever that is).

After a few days of sleeping on the problem I thought the Dremel idea had the best chance - so I checked with a mate If I could borrow his rotary tool, and then called up the tool specialist to discuss the best bit to use. I asked the sales guy if a diamond encrusted burr or a carbide burr would be suitable. "Nah don't wast your time" he said. "Hardened steel?, You'll go through so many bits before you'll get anywhere. I've tried it myself".

Oh. Deflated. Time to call the professionals - I didn't want to make it worse again, by botching up my previous botch. So I called the fella from Melbourne City Landrover, and described the problem. Did he think they could un-botch my botch? He said that they couldn't, but he knew a fella who could. He goes by the name of The Thread Doctor, and he un-botches botches that others cannot.

--- Chapter Three ---

I contacted The Thread Doctor's mobile un-botching service. We arranged an appointment for the following Wednesday. On the Tuesday evening, I thought to myself, "Hmmm, The Thread Doctor's going to be here tomorrow, I'd better make sure that the other roof rail is okay too. So I prized off the plastic caps and set to work with the Torx head driver, and --snap-- another bolt head breaks off as I'm undoing it. It just twisted off.

So now I had two jobs for the Thread doctor. I wasn't even tempted to try another Ezi-out this time.

--- Chapter Four ---

Well The Thread Thread Doctor arrived today, with his arsenal of little tools. So here's what he did.

For the bolt without the Ezi-out, he first applied a loosening spray on the bolt, but he said that the Loctite that had been used would probably stop the spray from penetrating. Then he used a little rotary air tool with a carbide burr to create a guide hole (easier than a centre punch, he said), and then he drilled all the way through the bolt with a regular drill, and then increased the size of the hole using increasing drill sizes. He tried a larger Ezi-out at some point - but he didn't force it. There was too much Loctite. "If it doesn't just spin out - then give up", he said, He then just increased the drill diameter, to slightly larger than the thread size and the bolt shank just collapsed and came out.

He then drilled the captive nut out further, completely removing the thread and inserted a 6mm Helicoil, to re-thread the nut. Part One complete.

For the bolt with the Ezi-out, he used the Carbide burr, an elongated teardrop shaped bit, and ground down from above, just grinding out the Ezi-out. Took about a minute. Once the Ezi-out was gone he drilled through the bolt and widened the hole again. This time he tried his own Ezi-out again, and the broken shank spun nicely out of the captive nut. Job done

I could have faffed around for ages with a Dremel trying to find the right grinding bit I suppose, but I would have had to do the job twice when the other bolt head snapped off. As it turned out it was just so much quicker to get a professional onto the case.

--- After thought ---

Two broken bolts on my roof rails is a bit disconcerting. If I hadn't pulled them off and looked they might have come adrift with a load on the roof. It certainly didn't take much force for me to snap one of those bolts when undoing it.

There is some small amount of corrosion at the neck of a couple of the other bolts that I removed. There would be quite strong dynamic loads on those bolts, and they sit up there on the roof, year after year, getting wet, getting hot, getting stressed - I suppose it no wonder they give up the ghost eventually.

I've never exceeded the load recomendation (70kg) on the roof. The heaviest thing I've ever put up there was a spare wheel. (~40kg). But I did drive for hundreds of Kms over corrugated roads with the spare up there, so the bolts would have got their share of dynamic forces.

There's only six M6 bolts holding the roof rails down on my D3, and both of the rear bolts failed on me. I wonder if its because the front two fastenings are located closer together and the rear therefore get more stress from dynamic loads.

If your vehicle is getting on a bit like mine, and you've been placing loads on your roof rack for a few years, and you're planning a big trip soon, it just might be worth pulling off your roof rails, and replacing those M6 bolts with nice fresh unstressed ones before they go the way mine did.

Originally Posted by sniegy

I know this is late as i have had a 12month break or close to it from AULRO, because of personal reasons.
But where the bolt screws into the roof, The bit on the roof is a "NUT" if you grabbed a 13mm socket & slid it over the nut & undid the roof nut it would of just come undone & replacements can be ordered from spare parts. Some silastic when refitting the nut to the roof & you can then refer the roof rack.

Really? It looked welded to me. I certainly didn't try undoing it. If so it must extend below the roofline and have an outer thread below the roofline as well as having its inner thread where the roof rail bolt goes. It that right? I can't see how else it can be a nut.