Mustang Auto transmission slipping

Category: Transmission Repair

transmission pan

 This is a 1991 Ford Mustang with a 2.3 liter four cylinder engine. The automatic transmission is slipping when it’s shifting to higher gears. The first thing to check for is a leaking line which could suck air. The next thing to do when your transmission is slipping is to remove the transmission pan. When the pan is removed a couple things can be done. First the arrow points to the magnet that will pick up some of the worn material. There should be a minimal amount of material on it, if not there may be larger problems. Also this is the time to replace the transmission filter which may cause slipping also. This transmission needs to be rebuilt as it has worn clutches that need to be replaced. Most automatic transmissions are built very similar.

transmission rebuild kit

This is a standard automatic transmission rebuild kit for the ford mustang. Only someone with reasonable mechanical skills should attempt this. The bands and clutches are shown on top in the middle. The input and tailshaft seals are shown to the middle left. Below is the bellhousing that will need to be removed. There are 8 bolts that will need to be removed.


Below is the input shaft which will need to be removed. This section can be removed once the band is loosened. The arrows point to the connection points. There will be a stud and nut on the outside of this point to adjust the friction on the band. Then this section can be removed.

transmission band

Below is the input section that will carry half of the clutches. This is one of the clutch baskets and the other is behind the center section that will be removed next.

input shaft

Next the two bolts below will need to be removed so that the center section can be removed. First the valve body on the right will need to be removed so that these allen bolts can be accessed.

trans bolts

Below is a picture of the center section. On the right side are the backsides of the two allen bolts. The other thing that holds in this center section is a retaining clip that holds it by the outside. On the left side is the split in the retaining clip. 

bolts and ring

Below is the ring that held the center in and the input shaft section.

outer ring

Here is the center section removed behind here is the other clutch basket.

center section

The friction band will need to be loosened as with the first one.

bands and clutches

Next this clutch basket hub can now be removed. This is the inside of a clutch basket. These are the pieces that need to be removed and replaced. The clutches have teeth in the middle and outer part that will correspond to it’s basket. The steel plates and the clutches are staggered in the basket and must be replaced in the same order as removed from the top to the bottom. If not, the transmission will not work correctly. At this point the transmission is ready to reassemble. When reassembling the transmission the bands will need to be torqued to the specifications for that particular transmission. The torque must be correct for the friction to be right on the band. This is a general overview of what needs to be replaced when a transmission is slipping, always consult to it’s specs before repairing.

automatic clutch pack