Transmission, driveshaft and rear axle –...


Transmission, driveshaft and rear axle – sometimes those parts don´t get the attention they need! Although they are necessary for a good driving car!

Most Mopars we equipped with an automatic transmission, 62-78 all 3-Speeds. Smaller engines and lighter cars had a A904 installed, all others the A727. Therefore you will find the A904 (sometimes called TF6) mostly attached to /6 or SmallBlock V8´s.

The A727 (or TF8) was built with three different cases – for /6, Small Block and Big Block.  That means, if your Mopar has a Big Block (distributor up front) with an automatic transmission, it will be an A727. You can identify the A904 and the A727 easily by the shape of the oil pan and its gasket.

On Manual transmissions you either had a 3_Speed or a 4-Speed transmission, which is known as A833.

On the driveshaft side of the topic, we want to let you know, that there were only 2 types of u-joints. The small Type 7260 (1 1/16”)and the big type 7290 (1 1/8”). Real muscle cars have the bigger 7290 from factory.

Rear axle are defined by the diameter of the crown wheels.  Starting with 7 ¼” with the 9 bolts at the differential cover, following the 8 ¼” (10 bolts) and the mostly installed 8 ¾” rear axle. The 8 ¾” is easy to identify because of the welded differential cover. Bolted cover and tapered axle tubes tell the 9 ¼”. The biggest and heaviest version is the 9 ¾” axle, which is also known as DANA 60. 12 bolts on the differential cover and straight tubes will tell you.