Cactus, The Losi Mini-T steering servo has four wire connection (with 4 pin Dupont connector), which is not RC car standard. But, if you carefully unscrew and open up the Losi servo you will see that two of the wires are shunted together, so it is actually a 3 wire servo after all. This is a clue I will share. In most situations the Losi steering servo can be repaired, but it depends on what failed inside. I have four mini-t's ( red, blue, silver, and silver ( soon to be painted white) and have found that it is not the small circuit inside the servo that fails. Failure is usually gear issue or the small motor inside will become stuck. A gentle spin of the motor shaft will get it unstuck and should work again. As for the gears, there are two common issued I have encountered. The smallest gear on the motor shaft is supposed to be press fit. Over time this gear will slip on the spindle so it needs to be glued in place with a (tiny) amount of super glue or epoxy. The other gear that may cause servo failure is the control arm gear ( hex on top). This gear is keyed over the potentiometer shaft. Notice the potentiometer shaft has a flat. The potentiometer determines the servo position so it is important the shaft and gear mates. Gear sets are sold on ebay from time to time for about $5 USD.
Yes you can retrofit a HiTec HS-55 feather servo. You will need to perform some surgery. Remove the circuit inside the HS-55 and replace it with the circuit from the Losi servo.
I hope this information helps, Best of luck,
Andy
