alright so this is my third tranny on this truck...im about 300 miles away from hittin 70k on the motor and chassis and this current trans has mayb 5-6k on it...first tranny blew up second one the idiots who rebuilt the trans never tightend my driveshaft causin my trans case to break destroyin the trans altogether...and yesterday drive back up the mountains i had my o/d light start flashin ..and its been goin hard into the gears now the weather has been at freezin or below so that wasnt any major thing but havin the o/d light start flashin didnt make me happy...i checked the trans and the fluid and the only thing i noticed was where hte drive shaft goes into the transfer case its leaking..but not major just a lil..ive reset the light but the trans just dont feel right...my drive train is all stock and ive got 33x10or11.5 tires on 16in rims....too much tire for the trans? i wud think if it is i wuda blown up my rear? but before i confuse anyone my o/d light has done this a couple times..i kno i have overdrive cause i can feel it shift through all the gears...is the o/d light connect to a sensor on the trans and if it is is it something i can replace...mayb the senor is just malfunctioning?

 

I would take it back to the shop that built it and let them check it out.