T5 Steel Bearing Retainer
The stock, aluminum, bearing retainer will slowly gall and weaken due to constant friction against the steel shell of the throwout bearing. If you're using a performance clutch with heavier spring pressure, the retainer will wear even faster. Eventually the retainer can fail, leading to clutch and input shaft failure.

The transmission needs to out of the car, and drained of fluid. The gray discolored area on the first half of the retainer is due to galling and scratching from the throwout bearing. Remove the four 1/2" bolts holding the retainer to the case.	Use a screw driver in the notch at the sides of the flange and gently pry the retainer free from its silicone seal.
The old retainer will have a bearing race and possibly a shim ring. Be sure to transfer these to the new retainer.	The shim goes in first. The taper (small end) of the race must face towards the front of the trans. Note the new retainer should also have a front seal. Don't install it without one! Lightly coat the race and seal with ATF.
Clean the old silicone off the the case, and also wipe the input shaft clean of any grease and grime.	Place a bead of silicone or RTV around the flange of the new retainer, and slip it over the input shaft. Torque the bolts down to 18-20 lb.ft.

Tail Shaft Bushing and Seal.
The tailshaft bushing should be replaced if you bought your T5 transmission used, or if you are installing a new slip yoke. The bushing is available from Ford parts dealers for $5 to $7. The seal can be also be bought from Ford, but the big parts stores will have it for half the price (about $8.) Unfortunately the bushing can only be removed with a special puller. (Either the FORD T5/T56 puller, or a C4/C6 bushing puller.) It also takes a special "pipe" to knock in the new bushing all the way. The bottom line is that this is a tool you are not likely to have, or to find cheap. So you'll need to think ahead on this one, and call around to transmissions shops and see if they'll do it for cheap. If you have the transmission out of the car, our experience is that most shops will perform the whopping two minute procedure, for free. If you drive the car in, expect to pay up to an hours worth of labor, since they'll have to remove the driveshaft and drain/refill the case.

Synthetic ATF
First of all don't use anything but ATF (Mercon-Dextron II / III) in your T5. Unlike many manual transmissions, T5's do not work with gear oil or MTF. While many people question the value of synthetics, we've found that the T5 shifts smoother and there is less grinding with synthetics. Since you are only going slightly less than three quarts, it's worth spending the $10. Plus it will last longer and won't need replacing as often as conventional ATF. We like the Aamco synthetic blend, but Mobil one full synthetic works great as well for a few extra dollars.