Replacing the Spec Racer Ford Gen3 starter motor can be tricky as you have to reach up inside the back of the engine bay to get to the 3 mounting stud nuts. There is limited space and you end up having to get the nuts by feel.
10 & 15mm open end wrenches - engine studs
1/2inch open end wrench - electrical terminals
3/8 inch small ratchet
6 or 12-point 15mm socket
Replacing the Starter Motor
Jack up the rear of the car using the quick jack followed by the floor jack.
Use jack stands and get enough height so you can get under the car to reach the underside of the motor below the air intake. Ensure the jack stands are secure before climbing under the car.
Ensure the master switch is off and disconnect the battery.
There are three stud nuts that hold the starter motor in place. You can see the top nuts easier in the picture below without the air intake in place. The engine mounts and frame make it difficult to get through from the side and the intake makes it difficult to get through from the top. The easiest way is reach from under the motor.
When the engine ships from SCCA Enterprises there is thread locker on each of the studs. It is very difficult to remove the nuts the first time. It is highly recommend to work the nuts back and forth to remove the thread locker before installing the motor into the car. Make especially sure to do this for the middle nut. If you are worried about the starter motor coming loose you can use thread locker on the bottom nut which is the easiest to reach.
Disconnect the solenoid wire by sliding it off. Use a 1/2 inch wrench to undo the starter wire power lead. Note the wire color and especially position on the solenoid.
Come up from bellow the engine to reach the starter motor. Loosen the middle nut holding the starter motor on the engine studs using the the 15mm open end wrench. This is the hardest to reach nut to work loose as there is limited access space. I had to flip the wrench a few times to get a small rotation each time. A very tiny ratchet might work if you can get enough leverage to break it free. Once loose and no thread locker is in place you can remove with your hands.
The two outer stud nuts can be reached by using a ratchet with a 15mm socket, 12 points will make it easier. Removing the nuts can be difficult and will require working by feel for the top nut.
The last stud which is in upper position closest to the engine block will be difficult to reach.
With the 15mm nuts removed you should now be able to pull the starter motor out of the block. You will need to lift it, rotate and guide around any wiring to lower it down out of the engine bay.
Often the starter motor issue can be fixed by replacing the solenoid. Use the 10mm open wrench to remove the two bolts holding the solenoid in place. Use the 1/2 inch wrench to remove the ground connection to the solenoid. Note the position.
Be careful when taking the solenoid apart there is a spring and plunger. You will need to reassemble them back into place correctly the spring seats in the holes in the outer body and hooks into the plunger. Once in place push together the assembly and tighten the two bolts into place using the 10mm open ended wrench.
Slide the starter motor into position on the engine studs and tighten the outer nuts down with 15mm socket and small ratchet. The difficult to reach middle nut will require either the open ended wrench or a tiny ratchet to tighten fully into place.
Replace the starter wire onto the electrical terminal in the correct location and tighten with the 1/2 inch open end wrench. Slide the starter solenoid wire into place and make sure it is secure on the contact.
Be clear of the car and make sure it is in neutral.
Reconnect the battery, turn on the master and test to see the starter works. If the starter doesn't work, shut off the car and check your electrical connections again.
Once everything is working. Raise the car to remove the jack stands and lower the car with the floor jack.