problems with kickdown shift RPM

Jack the car up and secure on jack stands making sure it's a few inches higher in the back than the front so the atf runs into the main case.

Remove the driveshaft.

Unbolt and remove the cross member. You will need to support the trans from the pan (use a large flat board to support the whole area of the pan) so it doesn't drop down. It doesn't take much to support it.

Unscrew the speedometer cable

Directly under where the trans mount bolts onto on the bottom of the extension housing you'll see 2 large Phillips head screws holding a piece of metal about 1/2" wide by 3" long. Remove it. There's be a cork gasket underneath so be careful not to damage it removing it or you'll be replacing it.

Remove the bolts holding the extension housing onto the main case.

Under that piece of metal you removed you'll see the ends of a very large snap ring. You need to get that snap ring to let go of the rear bearing. I use a set of very large inside flat bill type snap ring pliers to spread the snap ring and then you pull the extension housing off. NOTE: sometimes that snap ring can be a bugger to get spread far enough if you don't have snap ring pliers big enough.

Once you have the ext housing off you'll see the governor riding on the output shaft. On each side there's a snap ring. You only need to take one off to pull the pin that holds the governor assy in place. I prefer to take the snap ring off the side the governor comes out of cause the snap ring is small and the opening on the other side is so small it's not easy to get the snap ring back on. Swap the governor and assemble in reverse order. I apply thread sealant to the extension housing bolts and torque them to 30 ft. lbs.

Here are some pics of a 904 I'm currently rebuilding.

1st picture is a pile of parts and the output shaft that has the governor and bearing on it.

2nd picture you can see the metal plate you need to remove

3rd pic is looking down into the black hole at the snap ring. Not easy to see the ends of it but that where it's at.

BTW: it might not be a bad idea to purchase a new extension housing to main case gasket cause sometimes they stick and tear when you take them apart.