When I bought my car, I discovered that emergency brake was destroyed by the previous owner when he changed wheels on the car and used too long of a lug bolt. Removing the rear rotor I discover that nothing was left and they removed all the emergency brake components.


No emergency brakes

I managed to get everything fixed except I had bunch of mismatched lug bolts.

Mismatched lug bolts.

In the above picture, the bolt on the left seems to work. It's 40mm long. The bolt on the right does not work for several reasons one of the reason it's too long. So trying to find proper replacements have been a pain. Since i have custom wheels getting matching bolts has been a slight challenge. Therefore, I am putting together a thread to document the type of lug bolts used on the crossfire.

Lug bolts have several different parameters 1) Face type, thread pattern, and length.

Lug Bolt Clamping Face
The bolt face is the surface that aligns the wheel to the hub and provides the clamping force to keep the wheel on. The crossfire uses the spherical face.



Thread Pattern
The crossfire hub uses M12x1.5 bolts. The M number is the diameter of the bolt which is 12mm. The 1.5 is the pitch of the thread, or the distance between peaks. In this case it is 1.5mm between peaks.


All about threads

Lug Bolt Length
I don't know what is the right length for the crossfire. I do know the length is important. You need enough thread to engage into the hub to keep the wheel onto the hub. Think of the thread as surface area that engages the clamping force. Too little thread will result into broken bolts. Too much thread will have the bolt going past the hub and possible damaging internal items. I am sure more that one crossfire emergency brake has been damaged with a custom wheel change.

For my car 40mm thread length seems to be about right.

Ordering Replacements.
I have found doing searches on "crossfire lug bolts" yields a bunch of kits without any specific details on the bolts. I did find one company that allowed me to match specifically my bolt.

https://lugnutguys.com/

I was able to search bolt pattern, length and face type and get replacements for my rear wheels.

Fancy Wheels


Any additions, corrections, discussions, and or adjustments are welcome.

 

Nice write-up.
Aside; where did you get the vehicle body graphics? (Black striping)

 

Great Question! The previous owner was a detailer and had a penchant additional graphics. He put the black stipe on the car. The segmented sections are hand cut and closeup you can see some variance. He also put that sparkly tape on the intake grille. Normally it's not my thing but I like it. If you want to repeat this design, start with two inch tape and cut an angle into the leading section. I did some searching as this might be a common sticker design. I could not find any or my google foo was off.

 

What wheels are those? I like.

 

They came with the car. I do like them, so thank you. I don't the exact details on the make and model of the wheel. Since the crossfire has different wheel sizes from front to back. You might be able to put together a find. I did a good search using the following key words:

Mercedes SLK OE wheels chrome 5 spoke

I did find some examples came close: https://www.ebay.com/itm/375446690183



Look for wheels to fit the 350 SLK 2004

Benz 2004 350 SLK

 

Nice write up about lug bolts. What do you have the back of your car, bike rack/luggage rack/baby seats?

 

Stock Crossfire and Mercedes use a cone type ball seat,, aftermarket use a taper seat.
as for length the front (you can use longer bolts) and because of the offset of the stock rims,
you have 30 offset on the front, where as on the rear you have 20 offset ,that is why the stock
lug bolts are the same front and rear. I posted all this info 5 or 6 years ago,, but here it is again.

Bolt taper and ball

Bolt taper and ball



crossfire

crossfire tire specs

19" tire chart Tire size max height 26.9 stock 26.0 285/35-19= 26.9 & 11.2 wide see tire chart

18"tire chart

20" tire chart

ball and taper bolt. hope u can see this

another 20" tire chart

 

Oh, I see what you meant. I had just brought the car home and the previous owner had extra seats. I had place them behind the car before I put those seats in the garage.

 

xintersecty
The original factory wheels, whether 7 or 15 spoke wheels, used OEMboltsare 40 mm with a ball seat. Any other aftermarket wheel, may not use OEM bolts due to the lug openings/shapes, such as the 5 spoke wheels you have on your Crossfire Roadster.
Good Luck,
Dennis
DTMenace

 

Thanks Dennis. Since my wheels were OE Mercedes replacements, they used the same bolt. It took me a while to figure that out. From the original picture of the lug nut that came on the car, you can see that longer bolt I took out of the wheel. I bet the previous owner bought those and put them on, destroying the E-Brake. I have chrome replacements coming.

 

My mech Miami Matt does have the complete rear brake system including the E-brake parts,, I will check with him to see how he wants for it
or you can text him He does not answer his phone ,,text ,,he will call u back put my name in your text and he will answer sooner
I am coming up to Blairsville Ga at the end of Oct,, maybe i could del .
maybe you could buy the rear hub complete with the e-brake system already in tact. Matt's number is 786 877 5959 jim

 

Jim, I have already rebuilt my E-Brake back last year. I appreciate the offer. Trust me, it was a total pain to put back together. This post was to help people pick the right lug bolts for their application.


Rebuilt E-Brake

 

sounds good ,,the best way to check if a lug bolt works is to insert it into the rim ,,, and have 5/8" sticking out the back of the rim.
then put a little puddy on the threads tighten the rim on the car at least with 3 lug bolts and remove the one with puddy
and make sure it goes through th hub , with 1 and only ONE thread... the front bolt can go through by as many as 5 to 7 or more threads jim