I just had a new after market clutch put in. Picked up my truck and now I have gear train noise in 3 rd gear at 15mph and 4th gear from 25 to 35mph. Before the new clutch there was no noise at all. If they put the wrong oil in tranny and transfercase would this cause the noise? Anyone got ideas???

 

I'll give you a bump but 3rd gear at 15mph sounds too slow to me. What about 1st or 2nd at 15mph. Same sound? What about 3rd at say 30 mph. Any noise? I'd guess your just lugging the engine and the clutch is slipping.

But I'm no tranny guy