Miata Steering Wheel Cowl Screw Size: A Quick Guide

The Mazda MX-5 Miata is a popular car for owners to modify and upgrade. One common modification is replacing the steering wheel, which requires knowledge of the correct screw size to attach the wheel to the adapter. The screw size for a Momo wheel is M5-.8 X 10mm Lg, with a pitch of .8. When removing the steering wheel, it is important to disconnect the battery and airbag first to ensure safety. The steering wheel is secured with a 21mm nut, and care should be taken not to damage the thread.

Steering wheel adapter screw size

The steering wheel adapter screw size for a Miata depends on the model of the car and the type of steering wheel. For example, the screw size for a Finish Line (Rosenthal) steering wheel hub adapter and a Momo wheel is M5-.8 X 10mm Lg. Meanwhile, the steering wheel nut thread size for a 1990 1.6 Eunos is M12 x 1.5.

It's important to note that removing the steering wheel of a Miata involves working with the airbag, which is an explosive device. Therefore, it is recommended that only a qualified mechanic performs this procedure. When removing the steering wheel, the negative cable should be disconnected from the battery, and the panel under the steering wheel should be removed. The clock spring connectors should also be disconnected before removing the steering wheel.

Additionally, when working with a live airbag module, it is crucial to ensure that the trim cover is pointed away from your body to prevent injury in case of accidental deployment. When placing the airbag module on a surface, the trim cover should be facing upward to reduce the motion of the module if it deploys accidentally.

Steering wheel nut thread damage

If you're experiencing steering wheel nut thread damage, it's important to take action to address the issue. Here are some detailed instructions and suggestions to help you deal with this problem:

Identifying the Issue

First, it's important to correctly identify the issue. If you notice that the steering wheel nut is missing or damaged, and the thread appears damaged, you may need to take steps to repair or replace the affected components.

Safety Precautions

Before attempting any repairs or modifications, it is crucial to prioritize safety. Working on a steering wheel involves handling the airbag, which is an explosive device. Therefore, it is highly recommended that only a qualified mechanic performs any work involving the removal of the steering wheel or airbag.

Seeking Professional Help

If you're unsure about repairing the thread damage, consider consulting a specialist. They can assess the extent of the damage and determine the best course of action. In some cases, they may recommend repairing the thread or replacing the steering column.

Finding the Correct Thread Pitch

To repair or replace the steering wheel nut, you need to identify the correct thread pitch. This information can be found using a thread gauge or a digital caliper. It's important to get the correct pitch to ensure the nut fits securely.

Cleaning and Repairing the Thread

If the thread is damaged, you can attempt to clean it up using a thread restoring file or a small fine triangular file. This can help improve the condition of the thread and allow the nut to be secured more easily.

Replacing the Steering Column

If the thread damage is extensive, you may need to replace the steering column. This can be a more straightforward option than attempting to repair the thread. However, it's important to note that a steering column replacement may require mechanical expertise.

Torque Specification

When installing a new steering wheel, it's important to follow the correct torque specification. The recommended torque specification for a Miata steering wheel is 29-36 ft-lbs.

Reattaching the Airbag

After making any necessary repairs or replacements, don't forget to reattach the airbag securely. Ensure that the cord on the airbag is properly attached to the steering wheel. Always handle the airbag with caution and follow safety guidelines to prevent accidental deployment.

Learning from Others' Experiences

Online forums can be a valuable resource for learning from others' experiences with steering wheel nut thread damage. For example, in one case, a Miata owner experienced thread damage and sought advice from a specialist. They eventually resolved the issue by using a file to repair the thread, allowing the nut to be secured properly.

In summary, steering wheel nut thread damage can be addressed through a combination of identifying the issue, prioritizing safety, seeking professional help, finding the correct thread pitch, cleaning or repairing the thread, or replacing the steering column. Always remember to follow safety guidelines when working with steering wheels and airbags.

Steering wheel removal

Tools Required:

• Phillips screwdriver
• 1/4-inch drive ratchet, extension, and 10mm socket
• 1/2-inch drive ratchet or breaker bar
• Short extension (or deep socket) and 21mm socket
• 10mm wrench

Step-by-Step Guide:

• Remove the negative cable from the battery using the 10mm wrench.
• Remove the panel under the steering wheel. There are two Phillips screws on the bottom edge.
• Disconnect the clock spring connectors (large blue and orange connector). First, disconnect the orange connector by unclipping the side clip. Then, disconnect the blue connector by unclipping the middle clip, which is covered by the orange connector.
• Insert the key into the ignition switch and unlock the steering column to turn the steering wheel.
• Locate and remove the four 10mm nuts on the back of the steering wheel. These nuts secure the airbag to the steering wheel.
• Lift the airbag off the wheel, taking care to notice the attached cord between the airbag and the wheel. Loosen the cord from the steering wheel and remove it.
• Disconnect the orange and blue connectors from the clip in the wheel, following the same process as for the clock spring connector. Set the airbag aside, ensuring the trim cover is pointed away from your body to prevent injury in case of accidental deployment.
• Center the steering wheel and mark the shaft stud (inside the nut) with a marker to indicate the straight-ahead position when the wheel is removed.
• Remove the 21mm nut.
• Remove the steering wheel by applying a rocking motion with one hand opposite the other, pulling towards you at the same time.
• Note the position of the clock spring, which has two pointer protrusions fitting into the steering wheel in a vertical up-and-down position. There is also a marker at the 12 o'clock position. Avoid moving the clock spring, or it will need to be reset. The centering directions are provided on the unit.
• For installation, simply follow these removal steps in reverse. Ensure that the clock spring protrusions line up with the holes in the wheel and that the wheel is centered with your mark on the shaft. The torque specification is 29-36 ft-lbs. Don't forget to attach the cord on the airbag to the steering wheel.

Note: Working with an airbag can be dangerous, and this procedure should only be performed by a qualified mechanic.

Steering column cover bolt size

The steering column cover bolt size for a Miata depends on the model of the car. For a 1990 1.6 Eunos, the steering column thread is M12, which comes in four different pitches: M12 x 1.75, M12 x 1.5, M12 x 1.25, and M12 x 1. The correct pitch for this model is M12 x 1.5.

For the NA model, the bolts that hold the bottom of the steering cover are self-tapping screws.

The steering wheel adapter screw size for a Finish Line (Rosenthal) steering wheel hub adapter is M5-.8 X 10mm Lg.

It is important to note that removing the steering wheel involves working with the airbag, which is an explosive device. This procedure should only be performed by a qualified mechanic.

Steering wheel replacement

Warning

An airbag is an explosive device and should be treated with extreme caution. The following instructions are for informational purposes only and should only be performed by a qualified mechanic.

Tools

• Phillips screwdriver
• 1/4 inch drive ratchet, extension, and 10mm socket
• 1/2 inch drive ratchet or breaker bar
• Short extension (or deep socket) and 21mm socket

Procedure

• Remove the negative cable from the battery (10mm wrench).
• Remove the panel under the steering wheel (2 Phillips screws on the bottom edge).
• Disconnect the clock spring connectors (large blue and orange connector). First, disconnect the orange connector (there is a clip on the side), then disconnect the blue connector (the clip is in the middle and covered by the orange connector).
• Insert the key into the ignition switch and unlock the steering column to turn the steering wheel.
• Locate and remove the 4, 10mm nuts on the back of the steering wheel (these nuts hold the airbag to the steering wheel).
• Lift the airbag off the wheel. You will notice a cord attached between it and the wheel. Loosen the cord from the steering wheel and remove.
• Disconnect the orange and blue connector from the clip in the wheel (same way as the clock spring connector). Set the airbag aside.
• Caution: When carrying a live airbag module, ensure the trim cover is pointed away from your body to prevent injury in case of accidental deployment. When placing a live airbag module on any surface, always face the trim cover upward to minimize movement if accidentally deployed.
• Center the steering wheel and mark the stud of the shaft (inside of the nut) with a marker to know the straight-ahead position when the wheel is removed.
• Remove the 21mm nut.
• Remove the wheel (a rocking motion with one hand opposite the other on the wheel, pulling toward you at the same time should loosen it).
• Note the position of the clock spring (there are 2 pointer protrusions that fit into the steering wheel and should be in a vertical up-and-down position). There is also a marker at the 12 o'clock position. Try not to move the clock spring or it will need to be reset. The directions for resetting are on the unit.
• Install the new wheel, ensuring the clock spring protrusions line up with the holes in the wheel, and the wheel is centered with your mark on the shaft. The torque specification is 29-36 ft-lbs.
• Reverse the removal process for installation. Do not forget to attach the cord on the airbag to the steering wheel.

Notes

• The steering wheel adapter screw size for a Miata is M5-.8 X 10mm Lg.
• Steering wheel replacement procedures involve working with the airbag. This is a complex task that should only be performed by a qualified mechanic.

Frequently asked questions