Fill your Toploader with any quality 75W-90 gear lubricant until
the oil level reaches the fill plug opening. It should take approx.
2 quarts. We recommend changing the gear lube for the first time
between 500 and 1000 miles to remove the grease used to pack the
needle bearings that has dissolved, Permatex, break in metal, glass
beads etc. We use several new parts in our transmissions and they
will seat in with each other during the break in period. It is
not uncommon to see very fine metal on the magnetic drain plug
when you drain the oil the first time.
We recommend changing the gear lube every 20-25,000 miles in normal
street driving applications. If you have higher than stock horsepower
or drive your car aggressively you should change the gear lube every
10-15,000 miles. For stock type applications 75W-90 should work well
in all climates. In heavy duty applications and hot climates 80W-140
will work best.
ROAD RACE TRANSMISSIONS
Toploaders used in racing applications need a break in period. Put
some EASY laps on the transmission at low to mid rpm lightly accelerating
and decelerating in each gear. This will give the gears a chance
to break in and dissolve the grease in the needle bearings used during
assembly. After a few laps, drain the transmission and clean the
magnetic drain plug, then fill with 2 quarts of high quality gear
lubricant. Once completed, the transmission should be race ready.
80W-140 seems to work best for competition applications. Change the
gear lubricant after every race event.
SYNTHETIC GEAR LUBE
Synthetic oil is very popular in the automotive industry today.
The way a Toploader is designed it needs a certain amount of friction
for the blocker rings to synchronize shifts. We have had people try
synthetics and say it works great and some say it doesn't work at
all. Everyone agrees that standard gear lubricant does work. The
biggest determining factor as to whether it will work or not is the
driver. If you drive your car normally and shift it normally synthetic
would be a great choice. If you drive aggressively or want to shift
fast then synthetic may not work well. If you try synthetic gear
lube and it does not work for your driving style drain the transmission
and try standard 80W-140 gear lubricant.