Front wheel bearings on the Mazda Miata are the weakest part of the vehicle. Unfortunately, they are critical to allowing you to race but fortunately the Miata gives a warning before they fail completely. Competition grade bearings exist, but for the price you can purchase 2.5 cheap bearings. This write up will show you some very quick tips to on how to replace bearings cheap and easy!
If your car sounds like the pads are dragging on one wheel, you are likely hearing the first warning signs of a bad wheel bearing. When you go around a hard turn, the sound will typically amplify in one direction, and soften when turning the other direction. You may not have the typical slop in the wheel when you shake the car, but you will hear the grinding sounds if your bearing is beginning to fail. Typically after a race in the rain the bearings need repacked with grease, otherwise you will be ordering replacements.
Local auto suppliers have bearing and hub assemblies that range in price from $22 to $100. Blueprinted competition bearings will cost you $200 dollars. Mathematically you can replace several economy bearings for the price of one premium bearing. Racing isn’t completely cheap, so a common bearing to opt for among frugal racers is a $70 Raybestos option (RAYBESTOS 713155 R-Line). The trick is to order the one for cars with ABS, regardless if your car has ABS or not, and you want to order the axle nut. Also, order longer wheel studs from a HUMMER H3 2006-2010. Verify they are M12 x 1.5 diameter and thread pitch. The Hummer studs are nice and long to fit your competition wheels lugs. The whole assembly should cost you around $80. The axle nut size is 29mm and the only special tool you’ll really need is a torque wrench that can read 120-150 ftlbs.
Removal is very straightforward. Simply impact the front axle nut off and discard the axle nut. You can keep it on hand as a spare, but absolutely use a new axle nut when we reassemble.
ABS bearings are cheaper than non-abs bearings. I have no idea why, but since we want to reduce weight you’ll want to tap the ABS ring off with a small hammer and punch. Be patient and hit it around the perimeter of the toothed ring in a few spots. You’ll take it off mm by mm, rather than with an aggressive blunt force.
We’ll need to remove those short OEM studs and press in your longer Hummer studs. A vise is your friend here as you do NOT want to hammer on the studs because you’ll wreck the threads. Then, a stud is going to break off on you during a tire change and your final event of the year will be saved by a kind racer who caries a spare. Don’t hammer the studs! The trick here is a deep well socket and your vise. Simply put the socket behind the stud you want to take off, and press your vise in on the other side. You won’t have to push far as the studs only have a 3/8 inch knurled base pressed into the hub. To press the new stud in, simply put the socket on the other side of of the bearing and push on the back side of the stud.
The length difference between the two studs is significant. You can really see the difference, and that extra length is critical for aftermarket wheels. Wheel changes become easier because the wheel doesn’t slide off the longer stud, lugs have more threads to “bite” on, and it’as easier hand tighten your lug nuts.
Assembly is very easy. Simply slide the completed hub assembly back on and tighten the axle nut to torque specs. On our car, the torque is 123-159 lbs-ft. You’ve got to punch the axle nut collar into the key way before you put your hub cap and wheel back on. That’s it – you’ve saved about $120.