Broken Driver's Side pinch bolt
 

I was in the process of replacing my front struts and the driver's side pinch bolt head snapped off. I never have luck with heat, easy-outs, and drilling anything these days especially on this vehicle.

In reading some posts here, I read that it is best to just replace the steering knuckle with a used one. The thing is, I have never done that before.

Any writeups on how to do this or youtube links? I see some youtube videos which seem to have this as a step to doing something else but wasn't sure.

Also, if I am getting a used one, what parts should be coming with it?

Finally, will this increase my need for an alignment over say just replacing the strut? I planned on waiting a bit for the alignment after replacing the strut.

Thanks.

Both of my front pinch bolts were seized in place and I ended up drilling them out. It's doable but tedious if you're willing to try. I've been successful getting seized pinch bolts on other cars with a good 2-300ft/lb impact, PB blaster, and heat. Lots of heat.

It's mostly straightforward. You'll probably want a new wheel bearing and ball joint. Unfasten outer tie rod and ball joint retaining nuts, unfasten axle nut. Remove axle and pull assembly out. It's more or less that easy. Install a new ball joint and wheel bearing (tie rod is probably ok if you remove it gently). This is why I would highly suggest buying a nice set of drill bits instead and drill the bolt out. If you just snapped the head maybe only one side is seized and you'll only have to drill one end. Install a through bolt and a nut when you're done. Much cheaper, and probably less work.

See above

Realistically no, as there is no adjustment in these components, but it wouldn't hurt to verify toe is still correct. Small changes in geometry can have an affect on toe and thus tire wear. Just double check with the car fully settled on flat ground with a tape measure. You can check it by yourself pretty easily.

Thanks for all of that. I guess that I can try drilling it out. Just seems like many here have failed. Could you expand on a plan for drilling the pinch bolt out e.g. drill type, drill bit size, type, etc?

My arms get tired pretty quick when I am trying to drill and it often feels like I am going nowhere. Wasn't a problem when I was younger. Maybe I am just old and cheap now when it comes to bits.

Appreciate any pointers there. Tools always trump replacement parts for me where possible. The problem starts when spendy tools don't work as they should, end up snapping etc., and you still end up purchasing a new part after all of that failure doubling the cost and time spent in my experience. This is all combined with the wait for good quality online purchased tools. A little frustrating all in all!

I also had one snap off, I simply drilled it out (yes PITA, use good bits and something for a cutting oil) and removed everything in the pinch zone. Then simply replaced it with a longer bolt and nut. As long as the bolt still allows the arm to pinch to the strut, it will be fine.
simply takes some effort and a couple of dollars for a nut and bolt.
Of course start with a smaller bit and work your way up, important thing is to keep the first bit aligned properly, after that the larger bits will just follow along.

Mine has been like this for well over 100k with no issues at all, including assembly and disassembly to remove axles.

Simply depends on how you want to do it.

Thanks for the input. So I grabbed a regular sized corded drill for this project instead of using my hammer drill in that position which probably is the root cause of my tiring out!

I was able to start off with a small bit and keep the hole centered which surprised the heck out of me. Things usually skate all over and aggravate me. So stupid question but the small bits are also smaller in length than the length of the bolt. Do I stop drilling with the small holes when the drill bit bottoms out and how do I know when it's time to move up to the next size drill bit and how do I have to go carefully from next size to size or do I just wing it?

I used to have this technique down but I am not nearly as good at it. Maybe I am just getting older and older vehicles with more siezed items? It used to be able to get to a given sized drill side and hit reverse then be able to back the bolt out. None of this easy out or reverse drill bit stuff that seems to seldom work out anymore.

While it takes a while, I usually just skip the next size up and go for the one after that as I'm increasing diameters (as long as the bits cut properly) while you probably could skip more, by doing it very gradual, it lessens the wear on the bits..

If you don't have bits long enough to go all the way through, you have the choice of purchasing long bits, or starting from the other side as as well, until the holes meet. This is another reason centering is important, centered on one side, is centered on the other.

As far as total diameter, it just depends on how patient you are and how much trouble you're having, you can end up leaving some of the old bolt in and reducing the pinch bolt size (within reason of course) or taking everything out, including the threads, to use an oversized bolt.
Up to you and also what size diameter and length bolt you can source for the replacement.

Thanks very much for helping me better understand the reason behind slowly increasing size. Less wear on the bits makes sense. I think that I have enough to go on here. I appreciate the help.

pm sent.

Received and thanks. I will proceed with the drilling method since I have more time than money at the moment and then move on to your method

It looks like you've already gotten some good responses here and through PM to help solve the issue, but for the sake of future forum users I'll post my methodology here.

You are correct that getting the drill centered is often quite difficult. Get a round punch with a point, and use that to make a dimple in the center of the location you want to drill (do this for all drilling to help improve accuracy) and it won't walk when you try and get it started. Start pretty small, something like 3/16". You need to be certain the drill is perpendicular to the hole, and that you don't move the drill side to side or top to bottom or you'll risk breaking the bit and then you're totally hosed.

With a very thin bit I'll generally just go in an inch or so. The deeper you go the easier your next size up will be, but you greatly increase your risk of breaking the bit if you're doing this with a hand drill. Step up the hole one size and drill a bit deeper. Use an oil or PB blaster to keep the bit cool. Work slowly with a 'moderate' drill speed. Using quality drill bits is key; you'll have no success using anything from harbor freight here.

I live in the midwest, so I've had a lot of practice with this unfortunately. I'm sure I've still got plenty to learn, but this is the method that worked for me. I drilled out my first pinch bolt with the knuckle still in the car, but I found it much easier to remove the whole assembly and stick it in a vise so I could work standing up. Patience is key here, you absolutely do not want to break a bit. Good luck!

It takes countless HOURS and DRILL Bits to drill out that bolt. $50 and 30mins to replace the knuckle....

I respectfully disagree. It's probably a half hour and one drill bit set (which are not consumed in the process). It also doesn't rely on you waiting for parts and trying to source a knuckle. To each their own, but its certainly not a multi-hour process; even when doing it for the first time.

Thanks for the methodologies MegaDan. I was able to get the drill bit centered which surprised me. I did use a center punch which mushroomed immediately the first time I hit it. Still, maybe that helped?

I will come back and let you know how this worked out. Since I have more time on my hands than money, I will try to drill it out. I am willing to bet that this doesn't work in my case. In the case of my oil pan, I could not even remove the plug on a work bench after using ever trick in the book.....plus the price of a knuckle on Ebay is more like $80 shipped or so...then the price of a ball joint popper etc.

It's splitting hairs but heck it's a conversation at least....and at least there are options.

Thanks.

Go to the classified section here on NAM, there are MANY members/vendors parting out cars.

I have. I even have my own WTB ad up there but it's been crickets so far.

I missed this post, haha.

So I tried to drill out from both sides of the bolt. It started like butter at first. I used lots of cutting oil and worked carefully. I increased the bit size slowly but noticed something I have never seen before. I'd put the bit in and the bit would break with no violence or clue whatsoever. I'd simply remove the bit and it would be gone! Fortunately, this only took me about 20 minutes of time to determine.

I shall now learn what it's like to replace a steering knuckle I guess. :)

So if I do a query for knuckle on ebay it is like $120 shipped. If I do a query for spindle, I get spindle/knuckle for about $50 shipped. The pictures are not very detailed though so I am not sure what I am looking at.

Can you guys help me pick one? Also are all of the Base and S knuckles are the same? Is it possible to just get the spindle and not the knuckle? I don't want to get the wrong part and have to wait 3 times as long....Thanks!

https://www.ebay.com/sch/i.html?_fro..._sop=15&_pgn=2

The one from seller LKQ is mislabeled; is not for a first gen Mini. The one from AceAutoWrecker is the correct model but wrong side. I only viewed the first page of the listing.

Thanks for doing that. This search is hard on the eyes. No many disassembled and ready to view....hmmm wonder why.

When in doubt, use realoem to verify the exact part number you're searching for. In your case, looks like:

31216757498

https://www.realoem.com/bmw/enUS/sho...diagId=31_0679

Thanks for chiming in it is for the left one so....
31216757497

Almost $100 on ebay for a used one. The rest were complete rust buckets.

Whoops, too fast with the copy/paste...

So...the other option is local craigslist, junk yard or car-part.com.

Let us know how it works out.

Don't forget, if you can't find one reasonable, you can pull that one and have I local machine shop drill it out for you.

Yep will do. Thanks.