Does it hurt anything if you run more in 4th gear than in 5th? I'm running 32 by 11.5 tires with a 3 inch lift and in 4th gear at 50(given the speedo is correct) I"m at 2500 rpm's. At 50 in fifth I'm at 2,000. I've only had it for a week and haven't had time to check the speedo yet. It just seems to struggle more in fifth. Is fifth gear on the YJ just like overdrive or can you actually burn out 4th gear if you keep it in it all the time.