I tend to lean on the side of over maintenance. When I did the initial change, there were definately tiny metal particles from the break in.
http://www.5speedtransmissions.com
Q: What is the proper break-in procedure for a TREMEC TR-3550/TKO 5sp?
A:
Put 3qt of good quality ATF (Auto Transmission Fluid) (Dexron) into the transmission. Pour in through shifter mount, or through one of the top plates. You can use the fill plug on the side of the transmission also (afterall, that's what it's for!). It's just easier to pour it in from the top if you can.
Put car on jacks, run the transmission up and down through all gears repeatedly for 15 minutes. This will allow the gears to break in properly (yes, with the engine running)
After 500-700 miles, drain the ATF, and put in 3qt of the GM Synchromesh fluid, the part number is 12345349. If it's a race car only, then switch to the GM Synchromesh after the initial break-in.
Don't use
synthetic lube for 6000-8000 miles. In fact, we don't recommend
synthetic, just stick with the GM Synchromesh.