BMR camber bolt failure

[fullboogie]

UPDATE: please see post #30 regarding BMR's response to this issue.

I've had an awful clunking in my front end lately, so I pulled the wheels off today to see if anything was obviously wrong. Per Van's recommendation, I also checked the sway bar end links. While checking everything with my torque wrench I found that the passenger side strut, where it mounts to the steering knuckle, was obviously loose (I could see a gap on either side of the ear that is sandwiched by the strut). When I put my torque wrench on the bolts, I found the nut on the lower strut bolt (BMR camber bolt) just spun and spun. In fact, no amount of cajoling would remove the nut from the bolt - I had to cut off the bolt head with a cutoff wheel and slip the bolt out.

I do not use impact wrenches to install parts, ever. I used my digital Snap On torque wrench to install all my front/rear suspension parts about 6 weeks ago, so there is no way I overtorqued this bolt. Given that this bolt was likely going to fail at some point, this really concerns me. Has anyone ever had this happen??? I guess I'm going to have to fork out the money for camber plates now, which is something I did not want to have to do. :shrug:

And while I'm at it, what plates are most people using for a DD? The J&M's are attractive due to price, but are they any good? Anything else you recommend?

 

[NuclearPower]

Sorry to hear. I am starting to have some concern for BMR products. Their A arms have been failing also, not sure if the current design or the older design...I was thinking about installing these bolts to fix the front alignment after installing the BMR springs, but not so sure now.

As for the camber plates...What I have heard and read is that for daily drivers they are not good. Since the adjustment is made at the top of the strut tower it moves no matter what. All the torque and force that the strut sees is transmitted up to the top plate and causes it to move. Their is a guy with a fox body all souped up just down the street and he says that he has to have the car aligned about every 3 months.

 

[fullboogie]

Thanks, Nuclear.

I'd post pics of the bolt, but you really can't see anything. The nut is still on the bolt, and just spins and spins - I can't get it off. Obviously either the bolt or the nut threads are damaged, but there should be no way this happened. I'm OCD when it comes to using a torque wrench for proper bolt/nut torque, so I have to believe it's a fastener failure. Not a happy camper right now, because my car is down until I find a fix for this problem...

 

[fullboogie]

Ok, after doing some research on this site, I decided to take a few pics. As you can see in the pics below, the hole in the strut is 14mm while the BMR bolt is 12mm. Look at that gap! I'm trying to figure out how this arrangement could possibly hold the strut to the steering knuckle without moving around??? I know this is a bit off topic from the original topic of fastener failure, but the more I look at these the more I think they are a terrible idea...

 

[ZOMBEAST]

I ditched my plates and rotated the stock plates 180 degrees. Try a search.

 

[fullboogie]

I did see your post, Beast, and that's probably what I'm going to try - along with the "-C" strut mounts. Thanks for your help.

 

[Tob]

I know this is a bit off topic from the original topic of fastener failure, but the more I look at these the more I think they are a terrible idea...

If you are talking about these, then yes, they are a horrible idea. I cringe every time I see someone post them as a suggestion to use when alignment is a concern. Usually I see someone recommend them instead of using a caster/camber plate.

As Jack Hidley of Maximum Motorsports put it...

You don't want to adjust camber at the strut to spindle interface. As it is, the strut ear/spindle ear joint flexes enough for the spindles to break. Using camber bolts here with a potentially reduced or more uneven clamping load, is not a good idea.

He was on to something. Some time in 2009, there were a few documented S197 chassis spindle failures. They were cracking midway through the upper ear.

Some thought it was simply the forgings failing from faulty design. It appears to have been more than that. Here's a quote from an individual that passed some information on from someone "very familiar with Mustang Challenge cars" regarding the issue...

They have seen cracks of the type I experienced and a similar failure. These failures are caused by the bolts loosening up. Cobblestone type conditions (heavy race track curbing) will tend the make the bolts loosen, as will improper torque in the first place.

The 2010 spindle is machined slightly thicker in the strut mount area to give a little better clamping. They have also released new bolts with a fine thread and higher torque value. Note that the 2010 1/2 M.Y. spindle has a different ball joint hole and will not work.

The bottom line is that these bolts need to be regularly checked for proper torque. The course thread bolts need 200 nm /148 ft lbs. The newer fine thread bolts go to 225 nm /166 ft lbs. It would probably do good for anyone racing/autocrossing an S197 to get the newer bolts sooner rather than later.

From this thread.

To address the issue, Ford introduced as a running change some time in 2009, revised strut to spindle bolts and nuts. They went from a coarse thread to one with a finer pitch. It allowed Ford to raise the clamp force or torque at this juncture. When I swapped struts a couple of years ago, I noticed I had the early bolts and changed them to the latest design.

New bolt on the left and my original '09 bolt on the right...

As you can see in the pics below, the hole in the strut is 14mm while the BMR bolt is 12mm. Look at that gap! I'm trying to figure out how this arrangement could possibly hold the strut to the steering knuckle without moving around???

I know it is going to sound odd, but here is a quote from Jeff F, a former SVT/Ford Racing engineer that addresses the quote above from fullboogie...

The purpose of the fastener is to provide clamp load, not locate the joint. While in this case (and 99% of them for that matter) the bolt is certainly the only thing that locates it while putting it together, once it's together you are counting on the friction between the two parts to keep the joint from moving, not the shoulder of the bolt.

In summary - don't use reduced shank 'crash' bolts. They are a bad idea. Even worse when they are used on our beloved S197 chassis Mustangs due to potential spindle failures caused by insufficient clamp loads at the strut.

 

[fullboogie]

TOB - as always, you are a wealth of information. To answer your question, yes, the BMR bolts above are the exact ones I used. Never again. I just chucked the bolt into my drill press and spun it - it's also bent rather badly (not from anything I did). I'm sure it's bent from the spindle movement as a result of the thread failure. I have to wonder how close this thing was from breakage.

I'm going to have to visit the dealer for a new set of OEM bolts, so I'll just buy the ones in your picture above. Do you happen to know the Ford part # for those bolts? I only see the MM sticker on there.

While I'm at it, I'm switching out my lowrider BMR springs and buying some FRPP "L" or Steeda springs. Nice of BMR to sell GT springs as GT500 springs, too. As you can tell, I've really got the red-ass with BMR right now...

 

[Tob]

Boogie - I was able to beat my dealer's price substantially by purchasing them through MM. As for the part number, the new ones should be the ones that come up for your car when ordering for your year. If your parts guy is any good he should know about the revision. I'd mention it to him when ordering.

ON EDIT - GADZOOKS!!

Perusing BMR's instructional pdf for these bolts I noted the torque figures they are recommending for these bolts. NOT GOOD AT ALL!!

I brought up the relevant parts from Ford Parts site. The callout names are HB1 (for the M14 bolt) and HN3 (for the corresponding nut). I'm not sure how they are packaged, but the HN3 nut I brought up may come in a package of four. You better ask!

 

[evasive]

Simply too many serious failures from BMR in some pretty critical parts. I won't buy anything from them.

 

[09Troublemaker]

Simply too many serious failures from BMR in some pretty critical parts. I won't buy anything from them.

agreed... not looking so good for BMR

 

[fullboogie]

I still can't get the nut off, but here's the best pic I can get of the threads. Pretty obvious they pulled out. This is about how far the nut was out from the strut ear too:

 

[fullboogie]

Here's a quick video of the bolt in my cordless drill - pretty obvious the bolt is bent. I chucked the bolt up into my drill press and my drill, 10 ways to Sunday to make sure it was in there straight. The wobbling you see is from the bolt being bent. Chicken or the egg situation - not sure if the bolt bent, causing the threads to pull out; or the threads pulled out, allowing the bolt to nut to back off, thus causing the bolt to bend. Doesn't really matter at this point.

[youtube_browser]GaD5iQ3SZ-w&feature[/youtube_browser]

 

[Tob]

Some interesting quotes from a related thread...

My break had an oxidized section at an inboard corner, in the shape of a 30/60/90 triangle, with the short edge about 1/8" long. "
But that seems to cover it. So they have a new spindle model they are using huh? Well, there ya go.

The person I talked to described almost exactly how the broken part would look without having seen my pictures. So, they crack first and break later. He noted after one failure, they inspected a bunch of other race cars and found a bunch cracked.

The new spindle is an identical casting, they just machine the strut boss a little thicker (0.5mm IIRC) to have the bolt spend less time squeezing the ears to contact and more clamping.

my source stressed the importance of proper torque for this joint to the extreme. It is not a close enough or a little over is good enough thing.

It is not limited to Shelby's, we are just seeing it in autocross on Shelby's becuase they are the flavor of the week. The person I talked to was EXTREMELY confident that this problem is caused by improperly torqued bolts or ones that loosen up. It has been indicated that on new bolts, you want to check the torque again after 24 hours to account for stretch. I would be willing to bet that 95% of strut installations do not involve a torque wrench, probably even on race teams (at least until this problem was found)

The source I spoke with can't be identified, but works directly with Mustang Challenge cars and worked with Ford when they had this problem. From the sound of what he told me, they did some pretty serious looking at this problem.

Not sure what all that means. My gut is that the typical car, torqued properly from the factory and not getting struts for 75k miles, running around on 205 series tires will be OK, and Ford isn't going to see a problem.

The "bend" is in the caster direction, not the camber, BTW.

The direction of the failure and possible bend are radially from brake torque. E.G. strut stays put, spindle tries to rotate forward.

 

[evasive]

Link to the correct, updated bolts:

Strut to spindle mounting hardware kit, 2005+ Mustang [MMF-3] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

Glad this came up as my new Koni Yellows just arrived today. Now I'm debating on trying to order new knuckles and updated factory front control arms with new ball joints. Will the 2009/2010 Front control arms fit a 2008?

 

[iwannacobra5]

i've got BMR camber bolts on mine that i had the shop instal when they did my alignment...now you've got me wondering if i should have my alignment checked....or install camber plates.

does a camber plate install require you to pop the entire strut off or can you just remove the top four strut nuts?

also, i'd be interested to hear if van has heard about these issues...

 

[evasive]

I'd remove and replace those BMR bolts and have your knuckle checked for cracks.

 

[6-Speed]

I'm OCD when it comes to using a torque wrench for proper bolt/nut torque, so I have to believe it's a fastener failure. Not a happy camper right now, because my car is down until I find a fix for this problem...

Do you recall the torque value that you tightened the camber bolts to?

 

[6-Speed]

I don't know why anyone would replace a 14mm bolt with a 12mm bolt and use half the specified torque to fasten a critical area such as the spindle. I shake my head every time I read someone recommending them ... they must know more than the Ford engineers do. :nonono:

 

[iwannacobra5]

I'd remove and replace those BMR bolts and have your knuckle checked for cracks.

i haven't taken the car to the track and rarely beat on it, so hopefully there's no damage to the spindle. i'm not sure where i'd even take it to have it checked?