Quote Originally Posted by Trannyman95 View Post
Unless your drive and driven sprockets were replace with the correct ones it will throw an incorrect gear ratio code as I mentioned above. Did you check the "Current gear ratio" in 3rd gear yet? Without knowing the data here there is no reason to look into anything else yet.
Trannyman... the transmission builder tells me "the gears have 33 tooth drive and 37 tooth driven" for a ratio of 1.1212. The HD differential has a 3.29 ratio. This leads me to believe that the transmssion has a final drive ratio of 2.93 (3.29/1.1212=2.93). Is that correct? If it is correct... then I will have to send back to the transmission builder because I asked him to build me a HD transmission with the GT gearing so that I would not have to change my PCM. If the transmission had the GT gearing then I would assume the drive and driven gears would have the same tooth count - right... say at 35 (half way in between the 33 and 37)?

Question... how do I determine the differential ratio? Do I take the tooth count from the ring and divid by the tooth count of the sun gear?

NOTE. I have not changed the PCM from the stock GT.