I just bought a 2001 Ford f150 SuperCab Regency from a private owner that was the second owner transmission was replace.it has hundred and sixtwhen the air conditioner is on it is shifting really hard
Since the two systems AC and trans are isolated and unrelated the only common between is the serpentine belt. When the AC clutch kicks in it is causing more a demand on the engine's torque, than normal. So the engine is being taxed hard. This is a complex problem and I am telling you now I do not have the answer, but I have a few suggestions which may be a solution. 1) the AC compressor could be working harder because it is low on r134a refrigerant. 2) your trans fluid is low. Check it with the engine hot, and if it needs more fluid add Lucas Transfix. If it does not, do NOT or fill it. That will cause leaks 3) check the tension on your serpentine belt. There should be an indicator on the tensioner to say if it is within working limits. BUT if you see the belt shaking and not moving smoothly then the belt does need to be replaced.
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