A couple of days ago, we receive a customer who owns a BMW G30. After communicating the demand and confirming the factory data, we know that the main requirement of the customer is to enhance the three-dimensional sense of his BMW G30. Taking this opportunity, we can introduce the detailed steps and precautions for installing the wheel spacers. Correct Installation is critical to the vehicle’s performance and your safety. So let’s get it!

Short Data about BMW G30                            Tools We Need

Center Bore: 66.5mm                                                           ·Jack     ·Tripod

PCD: 5×112                                                                                ·Torque Wrench

Wheel fasteners: Lug bolts                                                ·Extension Rod

Wheel Tightening Torque: 140Nm                                  ·Lubricating Spray    ·Rag

Thread Size: M14×1.25                                                         ·Sand Paper(400 grits)

(Notice: The data is just suitable for factory setup, if you have any modifications, please consult a professional. Want consultation? Click here→  )

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Security Check

Before the fitting, the most important preparation you should never forget is—Security Check. After parking on level ground, turn off the flame and confirm that the handbrake is in place to avoid tragedy.

★  Pre-release the bolts

Slightly loosen the factory bolts with a cross wrench. There are four sizes of sleeves on the wrench—17, 19, 21, and 23 mm. If you can’t judge the right size, just try one by one. Be careful not to scratch your hub with the sleeve. In this BMW G30, 17mm is matched. This step is to reduce the burden of the wheel (particularly on large off-road vehicles) caused by the lifting height after using the jack.)



Lifting the vehicle with a jack

Carefully identify the jacking point where the jack engages on the edge of the chassis. For most vehicles, this specially designed point is always reinforced metal rib. It’s a suitable height when you can put in a tripod. Tripod serves as secondary insurance. Never put your head or body under the vehicle at any time!

★ Remove the bolts

This step can be easier relatively owing to the pre-release step. There are three points to note there. The first is loosening the bolts diagonally to ensure that the tire leaves the axle steadily to avoid scratches caused by uneven weight. The second is after you have loosened the first or second bolt, insert an extension rod to fix the tire to prevent the tire from falling off suddenly after all the bolts are removed. The third is carefully put down the wheels on the ground and put them back down. For some special wheels, the edge of the rim may be higher than which of the tire, so the inner side faces down easily to damage the rim. In our service, we will strictly require the installer to follow every step, and your vehicle will not suffer any damage in our offline store. If you go to other stores to install, it is recommended that you still supervise next to it.

★ Remove the rust off the axle

Due to the friction and sand intrusion, there is rust on some axles that will not be specially maintained. If the rust is not removed, it will cause the gap between the wheel spacers and the axle, which will cause looseness, and accelerate the premature od wheel spacers. Spray the rust remover/ lubricating spray, carefully rub with sandpaper from a small area to another, and then use a rag to wipe off the stains and the excess rust removal sprayed on the brake discs and brake calipers or other components.

Fixing the wheel spacers with matching bolts

For specifications of wheel spacers, you can refer to our previous detailed explanation. Click Here→

BMW G30 5 Series Wheel Spacers

This time, we installed 15mm and 20mm wheel spacer on the front and rear wheels respectively, and we have equipped the rear wheels with customized extension bolts which are grade 12.9 forged wheel bolts. One of the best advantages of the bolt-on wheel spacer is the custom bolts to ensure tightness. BONOSS Forged Active Cooling Wheel spacers are fitted to the axle tightly by the bolts that come along with the wheel spacers, and your factory bolts are used to connect the wheel spacers and the wheel. You can understand it as ”double insurance”. The bolt thread is the same as your stock ones. If you owned an unconventional wheel, we could also offer custom service. Tightening bolts also comply with the diagonal principle, ensuring uniform preload across all bolts and proper parallelism between the brake drum and the wheel.

BONOSS-forged-active-cooling-wheel-spacers-6061-T6 BONOSS grade12.9 forged extension wheel bolts tapered surface 14×1.25 40mm-15mm-20mm-BMW-G30-5×112-66.5mm-14×1.25mm-by-rongyan.5

Ensure the torque

You can pre-tighten the bolts in advance with the cross wrench, and then finally tighten them in torque with the torque wrench. This step is very vital, because no matter too loose or too tight, they are harmful. Loose bolts will cause the wheel spacers to fall off during driving, which is especially dangerous at high speed. Too tight bolts are not only difficult to disassemble, but also damage the bolts and cause safety hazards. However, the torque you need is not very rigid data. For example, in this case of stalling for BMW G30, the torque, in theory, needs to be 140 NM, but in fact, it is suitable in the range of 130-140 NM.

There is a reference to the torque corresponding to the bolts with different parameters.

  • M12x1.25: 113NM (83.3 Ft-tb)

  • M12x1.50: 113NM (83.3 Ft-tb)

  • M14x1.25: 140NM (103.5 Ft-tb)

  • M14x1.50: 140NM (103.5 Ft-tb)

Install the wheel and Recheck the tightness

Same as the above two steps, install the hub outside the wheel spacers. When you use the torque wrench, the bolt is in the right tightness until you hear a “click”. In the end, to ensure the tightness of bolts, you’d better start the car and let the tires rotate a few times to observe the condition of the wheels. If you find abnormalities, check the bolts again. If you are not sure, you can go to a professional experience store. We also welcome you to consult any relevant professional knowledge.