(Cross-posted to NorCalEvo.net.
Before you begin
These instructions detail how to remove the front wheel hub assembly and replace the front wheel studs on the Evo 8 (Evo 7-9 should be identical); the procedure for replacing the rear wheel studs will be similar. While it's possible to replace the wheel studs without removing the hub from the car, hammering on the wheel studs with the hub in place can damage the wheel bearings.
As with all car work, a few rules of thumb apply: take your time, use the right tools, wear appropriate protective safety gear, and if you don't feel comfortable doing the work yourself, get help or take it to a professional.
Time: with the right knowledge and tools, this job can be done in less than an hour per corner. Ideally it should be done on a car that's had some time to cool, since you probably don't want to handle brake or hub components when they're hot, and the lug studs may be more tightly seated when hot due to thermal expansion.
- wheel studs
- spare open-ended lug nuts or M12x1.5 nuts and washers (for pulling the lug studs)
- anti-seize compound (optional)
The wheel studs being installed here are those included with the H&R 5mm wheel spacer kit. Interestingly, although the spacers are 5 mm, the studs themselves are only about 3 mm longer than stock. As a result the 5zigen FN01R-C wheels I have are held on by about 6.5 threads of the lug nuts (torqued)--6 being considered by some to be the bare minimum to safely hold a wheel. Longer wheel studs are available, for example the Kyo-Ei studs from Road Race Engineering (22 mm longer than stock), though you'll need to use open-ended lugnuts.
- 17 mm and 19 mm hex sockets
- 21 mm deep-drive socket (or whatever you need to undo the lug nuts)
- ratchet and socket extension(s)
- breaker bar or impact wrench
- 32 mm axle nut socket (or deep-drive 32 mm hex socket)
- torque wrench
- needlenose pliers
- PB-Blaster, WD-40, Liquid Wrench, etc. (optional)
Hub assembly removal
Jack up the corner of the car you're working on. Don't jack up both sides; keeping one tire on the ground will prevent the front wheels from spinning freely.
Undo the lug nuts and remove the wheel.
A cotter pin secures the axle nut in position; straighten it and pull it out.
Use the axle nut socket and breaker bar (or impact wrench) to break loose the axle nut. It may be easier if you fix the axle in place by having a someone step on the brakes.
Don't undo the nut just yet.
Unbolt the two bolts holding the brake caliper assembly to the knuckle. Then use a disc brake spreader tool--or your hands--to open up the brake pads and pistons a bit and remove the brake caliper from brake rotor. Use a zip tie to hang the caliper out of the way. Then remove the brake rotor.
The hub assembly is bolted to the knuckle with four bolts (three seen in the photo below).
The tie rod interferes with access to some of the bolts--when the wheel is straight. Turn the key to the "on" position to prevent the steering wheel from locking, and turn the wheel fully towards the side your're working on. This will allow you to undo the two front bolts. Turn the wheel fully away, and you'll be able to access the two rear bolts.
Once you've undone the bolts holding the hub assembly, straighten the wheel and undo the axle nut. There's also a big split washer under the axle nut that you need to remove. Note its orientation--tapered side out.
With all the bolts and axle nut undone, the wheel hub assembly will come off. A few light
taps of the hammer may be needed to get it loose; if it's seized onto the axle spline, you may need a slide hammer with an axle puller adapter to pull it loose, though I was easily able to pull mine off even after 35k miles.
Wheel stud removal
If you have a press you can use it remove the lug studs but the easiest way is simply to hammer them out. With the hub off the car, hammering on the studs no longer risks damaging the wheel bearings. You may wish to spray the studs with a bit of PB-Blaster or WD-40 to loosen them a bit before extracting them. Hold the hub firmly and strike the lug stud; even with my puny muscles, 2-3 strikes of the hammer was enough to pop out each stud.
Wheel stud installation
If you have an impact wrench you can install the studs with the hub off the car; otherwise it's much easier to with the hub back on. Thread the hub back on to the axle spline, and put the axle nut and washer back (don't tighten them yet--not that you can) to hold it in place. Then put on the hub assembly bolts; use the same wheel-turning trick you used to remove them to easily access them. Torque the bolts to 88 N-m (65 ft-lb). Then tighten the axle nut and torque to 226 N-m (167 ft-lb). Put the cotter pin back in place and bend it back.
By turning the hub to the right position, you can insert one lug stud. You'll need to jack up the other front wheel off the ground to be able to turn the hub.
To seat the lug stud, put a washer or two on it, then thread a nut (M12x1.5 size) or a spare open-ended lug nut onto it.
Tighten the latter using a ratchet, breaker bar or impact wrench until the stud is fully seated. Don't overdo it--you don't want to damage the stud by pulling it further than it can go.
Re-install brake rotor and caliper. You may need to push the brake pistons a bit more open to get caliper over the brake rotor. Torque the brake caliper bolts to 108 N-m (80 ft-lb).
Fit the new spacer and wheel and make sure everything fits and you have enough turns of the lug nuts on each stud to safely attach the wheel. To prevent lug nuts from binding or seizing, apply anti-seize compound to the lug studs.