Chrysler Crossfire
Hub rings

4, Wheel bolts:

Because of the vibrations I have at higher speed I also check the wheel bolts, they must also be of proper length and not differ too much in weight.

Checking the wheel bolt's length:

Before I installed the wheels I did a check of the wheel bolts. It's told that a bolt of this size must at least have fully 6 revolutions into the thread of the hub. But also important that they are not too long. They can hit something inside the hub, the ABS sensors, etc or the thread length doesn't match the car's hub thread in length. At the rear there is also the park brake system inside the disk.

The 40 mm wheel bolt's length on the inside of the wheel is about 30 mm, from that I must subtract the spacer and the thickness of the disc brake.

I put a rod into the wheel bolt hole, rotate the hub / disc to see how long I can protrude it inside with out hitting anything.

I got the total clearance to be 47 mm.

The thickness of this disc brake is 6 mm where the bolt hole is. The spacer add another 5 mm. Totally 11 mm until the bolt reach the threads inside the hub. The bolt's length on the inside of the wheel was 30 mm, subtract these 11 mm and you get 19 mm. That's less then the clearance of the 47 mm I measured above, but still the bolt is unnecessary long.

When installing the wheel and wheel bolts, don't forget to count how many revolutions the wheel bolt rotate into the hub's threads, at least 6 revolutions for these kind of bolts, otherwise you need longer bolts. If the bolts are very long as this bolt is and not threaded all the way it cause serious problem too. Other cars maybe have other bolts and other preferences. If you don't know exact how to do this, let the wheel shop do it for you ! It's about the car's and your safety !

Wheel bolts length and weight:

After I had measured what length of wheel bolts I need I found that 30 mm shaft length in front and 35 mm shaft length at rear will be correct. I already have 30 mm wheel bolts, and I ordered new 35 mm wheel bolts.

The new wheel bolts I ordered. They have the shaft length of 35 mm and will be used at the rear where I have the thicker 10 mm spacers.

The different wheel bolts I have now. From left: 30 mm shaft length to be used on the front wheels, middle new 35 mm shaft length to be used on the rear wheels, and the old 40 mm shaft length bolt that will be replaced. Note also the last bolt have a wrong shape at the flange, it's round, not conical which my wheels demand.

Installed on the old rear wheel, one of the bolts is a lock wheel bolt. The new 35 mm bolts are much more massive, I must check the weight to know of the difference between the wheel bolts and lock wheel bolts maybe can cause some unbalance and cause vibrations.

Compare the new 35 mm wheel bolt with the lock bolt. When I measured the clearance at rear I found that the wheel bolts shall not have longer shaft than 38 mm. I have to find shorter lock bolts, also the shape of the lock bolts flange is wrong.

At the rear with the 35 mm bolt the difference between the bolts are only 3 gram. In front with 30 mm bolt the difference to the lock bolt is 19 gram. 19 gram can maybe cause some small vibrations, easy to test, just replace the lock bolt with a standard 30 mm bolt. Some math, 19 gram at radius 56 mm correspond to 5 gram at the wheel rim where you put the balance weights. Balance weights came in the standard 5 and 10 gram, so maybe this lock wheel bolt can cause some unbalance and vibrations.

If I can find new 35 shaft lock bolts it probably will be okay in front and rear. But most lock wheel bolts are longer and you cut them to correct size.