The BA 10/5 is a light duty five speed transmission. It looks similar to the AX-15, but smaller and it is manufactured by Peugeot in France. The input shaft is 1 1/8" 10 spline and the output shaft can be 21 spline or 23 spline.

	Drivers side. Note "SIMI" and the number 3.28351 cast in the side.
	From the front with the bell housing removed. Note "SIMI" and the number 3.2839 cast in the front.
	The passenger side. Note the cool detail shots David got. The "YJ" in the plug and "SIMI" and 3.2835 cast on the side. The light square area is the build date tag riveted to the side.
	A top view.
	The passenger side.
	Here is a driver's side shot of an AX-5 for comparison. The AX-5 has regular ribbing on the drivers side and it uses a one piece cast aluminum case. The BA 10/5 uses a two piece cast aluminum case that is bolted together at the top and bottom.
	Engine side of the bell housing.
	Transmission side of the bell housing.

Usage

The BA 10/5 and the Aisin AX-5 were used in all Wranglers from 1987-mid 1989. It was also used in Cherokees (XJ) and Comanches (MJ) with the 2.8L V6, 2.5L I4, and 4.0L I6 from their introduction until 1989.

Transmission	1st	2nd	3rd	4th	5th	Rev
BA 10/5	3.39	2.33	1.44	1.00	0.79	N/A

Contributors

Photos courtesy David Moulton.