The bolts wont be stretched using the modified torque method decribed by cn90. I don't remember what the torque values were at half the torque angle and lower preload. I seem to recall on the order of 90-105 N·m of torque to get to spec but they will only perform that trick twice before they deform notably. On the third application of torque to angle they were stretching without adding more tension and usually will snap on the 4-5th time.

BMW uses this method to achieve a consistent clamping force of roughly 9000#

Using the modified torque procedure described by cn90, you will still achieve > 7500# of clamping force which is spec for the 10.9 bolts at 67 N·m torque.

The problem with using torque to tighten is the clamping force will drop significantly each re-use as the bolt to nut inteeface degrades.

Another way to look at it is this: to active the same clamping force with a reused fastener will require 10-20% more torque so how much clamping force is lost each re use when the torque is even the same.

The point of using TTY via TTA is that you get very consistent clamping force.

I'm planning to upgrade my bolts to 1/2" if I can get them to fit because I found some grade 8 T nuts which I think will hold themselves from turning up top and can be torqued normally to get the design clamp force unlimited times.

The plate is a structural part of the suspension which is how it ended up with the crazy bolt situation. You will lose body torsion strength and rectangular rigidity if the bolts aren't tightened close to design spec.

Problem solved!

Class 10.9 flange nut, coarse thread $0.62 ea. https://www.belmetric.com/coarse-c-3...10-p-6824.html

$3.72 for six.

Class 10.9 10x55 coarse thread flange bolt $1.02 ea. https://www.belmetric.com/10mm-c-2_1...c-p-14323.html

$6.12 for six.

That's $9.84 for bolts and nuts before tax and shipping. At that price, even if I was inclined to reuse the bolts, I'd buy these new and use them. Hell, I'll probably order two sets, so if something comes up and I need to r&r the plate short notice I'll have a set on hand.

For the record, they are
M10X1,25X24
correct ?

No. 10x1.5x55 Class 10.9 flange bolts with flange nuts

onthefence owns an X3 - not an X5. This makes some of these post very confusing...

onthefence, you know the E83 is a TOTALLY different beast from the E53, right?

The E83 X3 was designed and bulit by Magna Steyr in Austria, while the E53 X5 was (partially) design and built in the USA. They share many parts, including the basic engines in some cases, but are more different than similar.

So the correct answer about the reinforcment plates bolts for an E83 X3 is M10x1,25x24 :thumbup:

Best to use RealOEM and your VIN to confirm parts etc. and newtis.info to confirm torques and procedures - don't assume that what goes for the X5 also goes for the X3.

I think the X5 uses M10-1.5x55. That's from memory though.

At least one of mine is about 24mm after five cycles of torque to angle though :-)

Always best to add year and model of your X5 to signature so input is specific to what you own.

For the E53:

Threads, rating: M10 - 1.5 x 55mm, class 10.9.
bolts: 16mm hex head with captive flat washer. BMW PN: 31101096987
nuts: 16mm hex nut with flange. BMW PN: 33306760587

Things like a flange bolt vs. a captive flat washer will make a slight difference, but it would not bother me. If I ever found that mine were not re-usable to my own high standards, I'd replace with non-BMW fasteners that fit the most important parts of the spec (size and class).

Did you end up using these? The links are dead but I'm going to try to find equivalent hardware. I'll be putting the plate back up and it's the fourth or fifth time for these bolts. I didn't want to reuse them the last time but I did.

$173.21 for 6 bolts and nuts. $22 for one lousy bolt .. what the hell is going on. I can't believe what I'm looking at.

I guess they start to sell a lot of these because people wanting to replace them every single time. So crank the price up.

I'll go read 25 pages of this, but there should be a nice kit by now.

Yes, I did use them. They worked great. The one thing I had to do was get the captured washers off the stock bolts, drill them out slightly and put them on the Belmetric bolts. The Belmetric washers were not as wide. After I got these I looked further into it and at the time Belmetric carried class 12 bolts. Figured if I needed to replace these some time in the future I'd order some. Those shouldn't deform like the class 10's under full torque. Could reuse them virtually forever. https://belmetric.com/