Anyone know how to ID the gear ratio in the TH125C auto trans? I found a long thread on here about it but can not get any response (posts are quite old) and have ran out of ideas. I have 3 and can ready the metal tags to get the numbers. Please help if you can! Thank you in advance, Robert
Write down (or take pictures of) the numbers and take them to your local GM parts department. They can look them up for you. You may need the years of them too.
My parts books only cover 1982-1993, so the codes probably are not the same for your 3rd gen.
I imagine there is a website that list them,,, somewhere. Not real sure though.