Borg Warner 4405 Updated Shift Fork

Our updated shift fork with a longer roll pin provides deeper engagement in the shift cam. This updated fork along with the case repairs we do will give you many more miles of happy motoring with your Borg Warner 4405 transfer case.

Here is a link to the rear BW4405 case half

Here is a link to the front BW4405 case half

Borg Warner 4405 Front Case Half

This is the front case half for the Borg Warner 4405 transfer case. The oil pump stabilizer wears into the side of the case and the shift rail wears it's bore as well. When this happens the shift fork can disengage the shift cam and the transfer case fall out of gear. The first indication you will get is a whirring noise when you let off the gas. We have these case halves in stock. The core charge for the case halves will be refunded when the case is returned to us in rebuildable condition.


Here is the BW4405 rear case half.

Here is the special BW4405 fork we have.

AW55-50SN Planetary

The AW 55-50SN transmission has many problems and one of the chief is with its bushings. The planetary bushing fails most often and we are seeing stator and sun gear bushings spinning out also. To solve this problem we have developed a one piece bushing which has greater holding power in the planetary. The planet must be machined to accept the one piece bushing. Since the machine work involved is complicated we're offering exchange planets with the one piece bushing already installed.

There are two different planets available in the AW55-50SN transmission. See the picture with the red line in it that shows where to measure to be sure you get the right planet. See below for correct size and part number.

1.860" = Part # 31255

1.765" = Part # 44255

If you need the planet with the 1.765" measurement, click here.

There is a $100.00 core charge that will be refunded if the planet you send back has at least three of the four planet pins snug.

AW55-50SN Planetary

The AW 55-50SN transmission has many problems and one of the chief is with its bushings. The planetary bushing fails most often and we are seeing stator and sun gear bushings spinning out also. To solve this problem we have developed a one piece bushing which has greater holding power in the planetary. The planet must be machined to accept the one piece bushing. Since the machine work involved is complicated we're offering exchange planets with the one piece bushing already installed.

There are two different planets available in the AW55-50SN transmission. See the picture with the red line in it that shows where to measure to be sure you get the right planet. If you need the planet with the 1.860" measurement click here.

1.860" = Part # 31255

1.765" = Part # 44255

There is a $100.00 core charge that will be refunded if the planet you send back has at least three of the four planet pins snug.

Borg Warner 4405 Rear Case Half

This is the rear case half for the Borg Warner 4405 transfer case. The rear bearing wears in the housing bore and the shift rail wears it's bore as well. When this happens the shift fork can disengage the shift cam and the transfer case falls out of gear. The first indication you will get, is a whirring noise when you let off the gas. We have these case halves in stock.

We need to know if your case half has a hole for the speedometer. The hole where the speed sensor goes in is just above the rear output shaft yoke and points towards the driver's side of the vehicle. See picture above that shows the speedometer hole. This hole may not be finished drilled all the way through, in which case you need to order "without hole". Also look at the "Alternate Views" above and let us know if the case is made of aluminum or magnesium. There is a triangle under the hole where the shift rail for the motor comes out of the rear case. Inside that triangle will be an Al for aluminum or Mg for magnesium. Select "With speedometer hole" or "Without speedometer hole", on the upper right side of this page where it asks you to "Choose Your Options". The core charge for the case halves will be refunded when the case is returned to us in rebuildable condition.

Here is the BW4405 front case half.

Here is the special BW4405 fork we have