Rear seal for A230
I recently had a local transmission shop here in Washington PA go through the three speed for my 75 to make sure it was good to go after sitting for thirty five years, and though they gave it a clean bill of health, I was disappointed when I went to pick it up. They'd used the wrong output shaft seal(no boot) and excused the error saying the correct part wasn't available anywhere anymore. Frankly I didn't believe them, so I searched this blog and found this thread. Based on this thread I went ahead and ordered part number 8935-S, seen on the left in the photo. Its diameter is 2 1/4 inches, and though it worked for jose65cuda's 1970 transmission, it turned out to be too small for my 75. A little more research led to the two on the right. It seems transmissions from 74 on(someone correct me if I've got that wrong) were built to a slightly different standard and are referred to by the model number NP230, with NP meaning New Process. Part number 2506 from auto zone(and many other sources) has a diameter of 2 3/8 and is an exact match to the one removed from my transmission. Then it turns out there's a third variant. While my 75 three speed has an output shaft with 26 splines, there's another version of this trans that has a slightly larger output shaft with thirty splines. It would use part number 7300S seen on the right with a diameter of 2 1/2 inches, and some sources are saying it's the correct output shaft seal for the four speed A833 as well. Anyways, Since this thread deals with this issue I figured I'd put this here so all the information would be in one place. If any of this is wrong please add a correction below so folks aren't led astray.
I recently had a local transmission shop here in Washington PA go through the three speed for my 75 to make sure it was good to go after sitting for thirty five years, and though they gave it a clean bill of health, I was disappointed when I went to pick it up. They'd used the wrong output shaft seal(no boot) and excused the error saying the correct part wasn't available anywhere anymore. Frankly I didn't believe them, so I searched this blog and found this thread. Based on this thread I went ahead and ordered part number 8935-S, seen on the left in the photo. Its diameter is 2 1/4 inches, and though it worked for jose65cuda's 1970 transmission, it turned out to be too small for my 75. A little more research led to the two on the right. It seems transmissions from 74 on(someone correct me if I've got that wrong) were built to a slightly different standard and are referred to by the model number NP230, with NP meaning New Process. Part number 2506 from auto zone(and many other sources) has a diameter of 2 3/8 and is an exact match to the one removed from my transmission. Then it turns out there's a third variant. While my 75 three speed has an output shaft with 26 splines, there's another version of this trans that has a slightly larger output shaft with thirty splines. It would use part number 7300S seen on the right with a diameter of 2 1/2 inches, and some sources are saying it's the correct output shaft seal for the four speed A833 as well. Anyways, Since this thread deals with this issue I figured I'd put this here so all the information would be in one place. If any of this is wrong please add a correction below so folks aren't led astray.
