Changing the gear box oil on a Spec Racer Ford is relatively simple. Unfortunately we had to go through this process when we lost a transmission at the Sonoma weekend last year. Over night in the paddock we needed to swap in a new transmission. It is also a good idea to do it as part of annual maintenance.
Tools and Equipment:
Long Oil Funnel
10mm and 24mm Socket, Ratchet and Extension
3 quarts of gear oil (Redline D4 ATF)
Repalcing the Gearbox Oil
First thing to do is drain the gearbox oil using the 24mm socket and ratchet.
Drain into a pan and dispose of appropriately, most tracks have an onsite oil dump.
Before you remove the drain plug it is always a good idea to ensure you remove the fill plug. Sucks when there is an empty gear box and no way to fill it.
Use the 10mm socket and ratchet to remove the transmission fill plug. You probably need an extension to reach down between the chassis members and rocker arm. Once the bolt is removed slide out the hold tab. Pull up on the plug to remove it is held in place with an O-ring.
Inspect the removed plug and make sure the O-ring is good, replace if worn. Clean it off to ensure no debris gets back into the transmission.
Reinstall the drain plug and tighten in place.
Use a long funnel to reach down into the transmission.
Pour in fresh transmission oil. Talking to our partners at Red Line Synthetic Oil, they recommend MT-90 for use in the Spec Racer Ford Gen3.
I sit the bottle in the funnel to let it drain.
Fill the transmission until it is just below half of the white speedo cog, should be 2.5 to 3 quarts. If you overfill the transmission it will puke out fluid as it gets hot on your next few sessions out. Makes a mess and is a pain to clean.
Replace the transmission plug, slide in the clamping fork and torque the 10mm bolt in place. Simple and straight forward now get back out on track.