MT, my 4400 dumptruck sounds like a siren in granny gear when I let off the gas, quite a bit quieter when under load or accelerating, but still noisy - then when I get into second it quiets right down, but pops out of gear all the time, in fact, I can barely hold it in 2nd and still drive. What do you suppose is wrong with it? Quiet and smooth in 3rd and 4th. PTO is also relatively quiet. . . I have a 4 speed out of a same year (52) GMC 1/2 ton - will it fit?
