i dont personally run a losi for 1/8, but I have sold alot of them. I have noticed some main things to help increase the life of the servos ( other than the stock 2.0 rtr throttle servo, it is crazy they include a servo with only like 42 oz of torque for throttle, it is the breaking motion that hurts them).
Make sure your linkages are running as straight as possible, any angles in the motion can cause binding and will put a side load on the servo output shaft. Also make sure your carb shaft slides smoothly, no binding. Make sure your end points are set so the servo isnt trying to over extend for break, throttle, and left and right steering. Best way to do this is to pull full throttle, run your end point/travel adjustment up till the throttle stops moving, then back it down a couple clicks. Do the same for brake, and each steering direction, this will greatly greatly increase the life of servos, I have seen it over and over people burning up servos and then watch them throw a servo in, crank the travel up and watch the servos trying to twist out of their cases.
Also make sure nothing is making contact with the case, like the chassis, side guards, etc. Under a hard landing, if the chassis is slapping the servo case, or if the case is sitting aganst the chassis, it will do some damage to the servo, as will the vibration of 1/8 scale. If needed, space the servo up just a bit.
For budget 2.0 RTR guys on a budget or for more of a bashing buggy. Move the stock steering servo to the throttle, and put a JR Z650m on steering, or maybe even a Z4800T. Just make sure to do the above adjustments