96-01 V8 AWD to 4WD
By Darren Stadstad (stadx2)
Have you ever wondered why Ford put an AWD transfer case in the Explorer with the V8 option? I myself have heard many reasons. Frankly, I don’t really care what they are, I just don’t like the AWD; aside from having no low range, it robs power and reduces gas mileage.
Others like myself had pondered the feasibility of a conversion to a part-time transfer case with low range. Well, I’ve put the pondering to rest, because I’ve done it.
First of all, there are two ways to do this swap. One is to install an Atlas II t-case, which from what I was told can be configured to bolt right up. This is the easiest way, but the most expensive. This t-case will run you around $2500, but it’s bulletproof and has an extremely low range, which is great for rock crawling. Unfortunately, this also requires cutting a slot in your floor for the t-case shift levers. I was not willing to do that to my Explorer. I wanted something more ”factory-ish”, which brings me to the second way, swapping in a Borg-Warner 1350,1354, or a 4405 t-case. This way costs less, but the swap is more involved. These Borg-Warner t-cases have a 25 spline input socket and a 5-bolt pattern that bolts the t-case to the transmission 4WD adapter. The transmission in the V8 model Explorer (4R70W) has a 31 spline count output shaft and a 6-bolt pattern. To correct this problem, you need to use the “Advanced Adapters” 50-8405 adapter to mate the transmission and new t-case together. This requires pulling out the transmission to swap out this output shaft with the one supplied with Advanced Adapter’s kit (25 Spline) and bolting on the new adapter housing on the end of the transmission so you have a 5-bolt pattern. If you choose to go with an electric shift t-case or Control-Trac t-case, there is additional wiring to do as well.
To keep this swap “factory-ish”, I choose the Borg-Warner 4405 Control-Trac Electronic Transfer-Case, since this is what the V6 model Explorer uses. The Grand total for this swap including the transmission labor for swapping the output shaft was approximately $1437.
I’ll take you though step-by-step what I had to go through to make this swap work.
Feasibility……………
Because I was using a Control-Trac t-case, I needed the electronics to control it. Well, it happens that in at least the ‘98 model year truck, the wiring is already in place within the interior of the truck! The only wiring that is missing is a foot-long section of harness that actually connects to the t-case, the neutral input lead to the GEM from the transmission in the engine compartment, and a power lead from the maxi-fuse box under the hood. All the electronics that control the t-case simply plug right in to the existing harness plugs. VERY FEASIBLE INDEED!
Now I needed to gather the parts necessary to make this swap work.
The Parts……………….
Ray Laboto supplied me with the t-case he had in his ‘97 Explorer. For model year Explorers 1997-2001 you should be able to use any of the Control-Trac t-cases from 97-01. They all have the same plug harness and operate the same.
Borg-Warner 4405 Control-Trac Transfer-Case.
Next, you need the adapter from Advanced Adapters. Again, the model number is 50-8405. Side note…Advanced Adapters does make an adapter that will bolt up to these Borg-Warner t-cases that doesn’t require you to swap the output shaft in the transmission. Unfortunately, it adds too much length to the entire driveline (4inches), which would push your t-case right into the front of the gas tank.
Advanced Adapter’s 50-8405 and 25 spline output shaft
After checking out what Ford wanted for new dash components and electronics, I promptly went to the salvage yard to find the parts. Luckily I found all the parts I needed on one Explorer. Very Cool!
Radio bezel with 4WD switch
Wire harness that connects to t-case
Torque-on-demand relay
Transfer case shift relay
Generic Electronic Module (GEM)
I found out well into this swap that a needed the transmission-to-crossmember isolator off the V6 Explorer as well (I’ll explain later). I just ordered that from Ford Parts Network online.
Transmission-to-crossmember isolator
The Install………………
The first step in my swap was installing the electronics.
The first item I installed was the wire harness section that went from under the seat, through the floor, and to the transfer-case.
First you’ll need to take out the drivers seat so you can get underneath the carpet to access the plug.
This is the electrical plug you need to access. In the Ford electrical book, this plug is called C200.
After finding connector C200, find the rubber floor grommet just to the right of the connector and remove.
Now run the transfer-case wire harness through the floor and plug into the harness C200.
This is what the wire harness should look like under the truck. It’s the dirty light blue one on the right.
The next item to install is the Torque-on-Demand relay, which is located behind the passenger side air-bag.
IMPORTANT! Whenever handling air-bags remove the negative cable from your battery to avoid any chance of air-bag deployment!
Once the air bag is out of the way, to the left you will see a connector like this, into which you plug your Torque-on-Demand relay.
The Torque-on-Demand relay plugged in.
There is a small rivet on the relay on one side and a nut on the other that hooks and bolts onto behind a metal plate to the left of the air-bag like this.
The next items to install are the Transfer-Case Shift Relay and the replacement Generic Electronic Module. They are both located behind the radio bezel.
(I know this looks like a huge mess of wires, but with my Explorer, I’ve done quite a bit of audio work to it, which makes this look really scary! If your Explorer is stock in the audio department, it will be pretty clean back there.)
The Transfer-Case Shift Relay plug harness is gray; it’s located deeper down forward and to the left of the radio and has a plastic plug capping it off.
After removing the plug cap, plug in the Transfer-Case Shift Relay.
The next item to install is the replacement Generic Electronic Module (GEM). The V8 AWD Explorer came with a different GEM then the V6 4WD. Ford must have decided to use different GEMs because the AWD didn’t need the Control-Trac circuitry. In ‘98, Ford made three different GEMs for the Explorer, but only one of them is used with the 4WD V6 Explorer, making the choice obvious.
If this isn’t obvious to you, you need the GEM from a V6 4WD Explorer because is has the Control-Trac transfer-case.
This GEM module is what handles the control aspect of the Control-Trac shifting. It also controls various other electrical items in the truck including windshield wipers, interior/exterior lighting, suspension ride control, defrosters, etc. Knowing this, it is very important to get a GEM from the SAME YEAR Explorer you are doing the swap on, as many electrical items and their values have changed over the years. Trust me, I learned the hard way!
You will need to check with your Ford dealer parts department to find out what GEM you will need.
The GEM is directly to the left of the radio. Remove the two bottom screws and the four large electrical plugs on it, then lift up and to the right to remove.
Now with the new GEM and t-case shift relay in place, put the dash back together using the new radio bezel with the 4WD controls on it. DUH!
The electrical plug for the 4WD switch was the one that was plugged onto the back of your original bezel into a “dummy” plug. That plug goes into your “real” 4WD switch.
Lastly, you need to get power to the transfer case shift relay circuitry and the neutral input from the transmission to the GEM. Ford used a different wiring harness in the engine compartment between its V6 and V8 models. Because of that, the power wire that feeds the shift circuitry and the neutral input lead that feeds the GEM dead end at the plug harness in the firewall. To keep this as “factoryish” as I could, I decided to add the appropriate pins to the engine side of the plug harnesses and install the maxi-fuse in the designated spot in the fuse box instead of running new wires and tapping into the harness.
The plug harnesses are called C147 (shift power lead) and C148 (neutral lead) and are located to the right on the power brake booster in the engine compartment on the firewall.
I got some plug pins that go in to the C147 and C148 at the Ford dealership. They didn’t have any part numbers for these pins but they look like this. You need to get one large pin and one small pin. These get added to your existing plug harnesses.
On C147 for the power to the transfer-case shift relay, you need to find pin #5 (its written on the plastic) and push the plastic filler out.
Now that you have a hole punched through, remove the white pin retainer clip on the inside of the plug, with a needlenose pliers.
Now take the large plug pin and insert it in through the back of the plug and reinstall the pin retainer clip.
Plug C147 should look like this when finished.
Now move on to plug C148. This pin is for the neutral lead. Find pin #26 and follow the same procedure you did with C147, except use the small plug pin.
Now that you have these connectors finished, you need to get fused power to the C147 lead and get the C148 lead connected into the transmission.
Again, for C147 I wanted to keep it “factoryish”. So I added a “Maxi” type fuse to slot #6 in the under hood Maxi-fuse box. Of course, this happens to be where the fuse is supposed to be for the t-case shifting power.
If you look into the fuse slot you will notice that the metal connections the fuse needs are not there, so you need to get some more funny-looking connectors from your Ford dealership.
Take the bottom of the maxi-fuse box off to insert these plugs. You will need to pry up the metal power distribution grid to access the appropriate fuse slots.
These are the slots you need to insert the fuse connectors.
With the grid pried up, insert both fuse plug inserts into the corresponding slots.
When inserting the fuse plug connector that goes under the power grid, just tape off the end of the wire with electrical tape and bend it over towards the other fuse plug to keep it out of the way of the power grid forks. The metal power grid has a fork blade that will push up and make a good contact with the fuse connector once you push the grid back into place.
This is what it will look like from on top with both fuse connectors in their appropriate spots.
Don’t forget to add a 20 amp maxi fuse!
The other lead (the one not touching the power grid) from the fuse insert needs to get tied in to the C147 plug pin connector lead. You will need about 3 feet of 12 or 16-gauge wire to make the connection.
Now move on to the neutral lead connection.
Under the hood, look for a large electrical connector located on the firewall right above the engine’s air plenum.
On the left side of this plug, look for a red wire with a white stripe. This wire goes into pin#9 (be aware that there is more than one wire this color in this plug harness, so LOOK AT PIN #s!). This is the neutral ground lead that comes from the transmission. This is the closest spot to access this wire. Before soldering, check and make sure you have the right wire with your multi-meter. Place the transmission in neutral, put one of the multi-meter’s probes on a good ground the other on the wire, then check for continuity. The meter should beep with the transmission in neutral.
You need to strip back its insulation and solder on an extension wire from here to go to the C148 pin plug lead.
That’s it for the electrical portion of the swap.
As I said before, you will need to pull out your transmission to have the new output shaft installed. Taking out transfer-cases and transmissions has been done before, so I’ll skip over those procedures.
After removing your transmission, take it to a transmission shop and have them install the new output shaft. I got it done for $150. I bought a 4R70W shop manual so I could attempt to do this install myself, but was scared off by seeing all the exotic tools that are needed to disassemble/reassemble this transmission. Not to mention all the little parts.
Here’s my transmission before the new output shaft was installed with the OEM 6-bolt adapter (bottom) and the new 5-bolt AA adapter (top).
As you can tell, the AA adapter is about an inch shorter than the stock one. Because of this, you need to get your rear drive shaft lengthened one inch, and the front drive shaft shortened one inch. I got away without doing any modifications to the front drive shaft because I had a different shaft made for the front when I installed the suspension lift, so the slip yoke had plenty of travel in either direction. If your drive shaft is stock, you will more than likely need to have it shortened.
Here is the AWD transfer-case (left) next to the Control-Trac transfer-case (right).
You can see, size-wise, they are not that different.
After getting the transmission with the new output shaft back from the shop, but before you bolt on the t-case with the 4WD adapter, you will need to mill down some of the aluminum that makes up the oil catcher inside the AA adapter to get the transfer case to bolt up cleanly. I was surprised I had to do this. My guess is that since this adapter is technically made for the B/W 1350/1354, there must be a slight difference in the castings between the Borg/Warner 1350/1354 and the Borg/Warner 4405 Control-Trac. Not a big deal though.
This part is a kind of a big deal. I was a little disappointed to read in one of the inserts with the directions for the AA Adapter that if you are doing this swap on a 1988 or newer AODE (4R70W) you will need to shave about a ¼-inch off the end of the input spline socket on the transfer-case. So much for just bolting it on! The reason this socket spline needs to be trimmed down is because at its current length, when the transmission’s output shaft is inserted in the t-case spline socket, the t-case’s socket will bottom out on the transmission’s output shaft where it begins to taper to a larger diameter, causing driveline bearing preload.
I used my pneumatic cut-off wheel and carefully and evenly cut down the ¼-inch that was needed.
This is what it looks like all together with the new adapter and t-case.
Reinstall your transmission with the t-case off but leave the AA adapter on the transmission.
Once the transmission is reinstalled, install the transfer-case BEFORE installing the transmission crossmember. If you install the crossmember and isolator first, you won’t be able to get the bottom two bolts screwed into the transfer case because the transmission isolator will get in the way.
Two more things to modify, the V6 edition transmission crossmember isolator and the transmission crossmember.
The reason for using the V6 isolator is because it is taller than the V8 isolator and since the AA adaptor was designed to be used with a taller crossmember isolator it works perfectly. The transmission crossmember isolator needs to have three notches cut into it to avoid some of the bolt heads it mounts close to.
Here you can see the height difference between the two isolators. V8 (left) V6 (right)
Here are the modifications I made to the isolator.
With the t-case bolted in and torqued down, you can now bolt on the transmission crossmember isolator. Once the isolator is in, line up the crossmember with the studs on the isolator.
I needed to extend the slots forward an inch on my crossmember to get the isolator studs to pass through it.
Now with the transmission crossmember isolator studs passing through the crossmember, finish bolting up the crossmember to the frame.
Reinstall your front and rear driveshafts and check your clearances.
Take the plug harness that is dangling by your new Control-Trac t-case and plug it into the t-case’s wiring harness.
Now go out for a test drive and check to make sure everything is working properly and not making any funny noises.
Helpful Hint: To shift into low range you must be in neutral and have the brake applied, then wait for your 4WD Low dash light to come on.
That’s it! Happy Wheeling!
Parts & Costs Overview………..
-Borg/Warner 4405 Transfer Case(Used) $350 w/shipping
-Advanced Adapters 50-8405 AODE(4R70W) to B/W 1350/54
4WD Transfer Case Adapter with 25 spline output shaft $500
-Radio Bezel with 4WD switch, Torque-on-Demand Relay,
and Transfer Case Shift Relay (from salvage) $50
-Generic Electronic Module (GEM) for Control-Trac (from salvage) $50
-C200 to Transfer Case wire harness (from salvage) $20
-Plug harness pin inserts (no part #s) $0
-Fuse connector inserts (no part #s) $0
-20 Amp Maxi-Fuse $2
-Transmission Crossmember Isolator (part#F87Z-6068-KA) $25
-Labor for Transmission Output Shaft Install $150
-Transmission Jack Rental $25
-Transmission-to-4WD Adapter Gasket $10
-4WD Adapter-to-Transfer Case Gasket $20
-Transmission Fluid (synthetic) $35
-Rear Drive Shaft Lengthening $125
-Front Drive Shaft Shortening $75 (quote)
Grand Total $1437
By Darren Stadstad (stadx2)
Have you ever wondered why Ford put an AWD transfer case in the Explorer with the V8 option? I myself have heard many reasons. Frankly, I don’t really care what they are, I just don’t like the AWD; aside from having no low range, it robs power and reduces gas mileage.
Others like myself had pondered the feasibility of a conversion to a part-time transfer case with low range. Well, I’ve put the pondering to rest, because I’ve done it.
First of all, there are two ways to do this swap. One is to install an Atlas II t-case, which from what I was told can be configured to bolt right up. This is the easiest way, but the most expensive. This t-case will run you around $2500, but it’s bulletproof and has an extremely low range, which is great for rock crawling. Unfortunately, this also requires cutting a slot in your floor for the t-case shift levers. I was not willing to do that to my Explorer. I wanted something more ”factory-ish”, which brings me to the second way, swapping in a Borg-Warner 1350,1354, or a 4405 t-case. This way costs less, but the swap is more involved. These Borg-Warner t-cases have a 25 spline input socket and a 5-bolt pattern that bolts the t-case to the transmission 4WD adapter. The transmission in the V8 model Explorer (4R70W) has a 31 spline count output shaft and a 6-bolt pattern. To correct this problem, you need to use the “Advanced Adapters” 50-8405 adapter to mate the transmission and new t-case together. This requires pulling out the transmission to swap out this output shaft with the one supplied with Advanced Adapter’s kit (25 Spline) and bolting on the new adapter housing on the end of the transmission so you have a 5-bolt pattern. If you choose to go with an electric shift t-case or Control-Trac t-case, there is additional wiring to do as well.
To keep this swap “factory-ish”, I choose the Borg-Warner 4405 Control-Trac Electronic Transfer-Case, since this is what the V6 model Explorer uses. The Grand total for this swap including the transmission labor for swapping the output shaft was approximately $1437.
I’ll take you though step-by-step what I had to go through to make this swap work.
Feasibility……………
Because I was using a Control-Trac t-case, I needed the electronics to control it. Well, it happens that in at least the ‘98 model year truck, the wiring is already in place within the interior of the truck! The only wiring that is missing is a foot-long section of harness that actually connects to the t-case, the neutral input lead to the GEM from the transmission in the engine compartment, and a power lead from the maxi-fuse box under the hood. All the electronics that control the t-case simply plug right in to the existing harness plugs. VERY FEASIBLE INDEED!
Now I needed to gather the parts necessary to make this swap work.
The Parts……………….
Ray Laboto supplied me with the t-case he had in his ‘97 Explorer. For model year Explorers 1997-2001 you should be able to use any of the Control-Trac t-cases from 97-01. They all have the same plug harness and operate the same.
Borg-Warner 4405 Control-Trac Transfer-Case.
Next, you need the adapter from Advanced Adapters. Again, the model number is 50-8405. Side note…Advanced Adapters does make an adapter that will bolt up to these Borg-Warner t-cases that doesn’t require you to swap the output shaft in the transmission. Unfortunately, it adds too much length to the entire driveline (4inches), which would push your t-case right into the front of the gas tank.
Advanced Adapter’s 50-8405 and 25 spline output shaft
After checking out what Ford wanted for new dash components and electronics, I promptly went to the salvage yard to find the parts. Luckily I found all the parts I needed on one Explorer. Very Cool!
Radio bezel with 4WD switch
Wire harness that connects to t-case
Torque-on-demand relay
Transfer case shift relay
Generic Electronic Module (GEM)
I found out well into this swap that a needed the transmission-to-crossmember isolator off the V6 Explorer as well (I’ll explain later). I just ordered that from Ford Parts Network online.
Transmission-to-crossmember isolator
The Install………………
The first step in my swap was installing the electronics.
The first item I installed was the wire harness section that went from under the seat, through the floor, and to the transfer-case.
First you’ll need to take out the drivers seat so you can get underneath the carpet to access the plug.
This is the electrical plug you need to access. In the Ford electrical book, this plug is called C200.
After finding connector C200, find the rubber floor grommet just to the right of the connector and remove.
Now run the transfer-case wire harness through the floor and plug into the harness C200.
This is what the wire harness should look like under the truck. It’s the dirty light blue one on the right.
The next item to install is the Torque-on-Demand relay, which is located behind the passenger side air-bag.
IMPORTANT! Whenever handling air-bags remove the negative cable from your battery to avoid any chance of air-bag deployment!
Once the air bag is out of the way, to the left you will see a connector like this, into which you plug your Torque-on-Demand relay.
The Torque-on-Demand relay plugged in.
There is a small rivet on the relay on one side and a nut on the other that hooks and bolts onto behind a metal plate to the left of the air-bag like this.
The next items to install are the Transfer-Case Shift Relay and the replacement Generic Electronic Module. They are both located behind the radio bezel.
(I know this looks like a huge mess of wires, but with my Explorer, I’ve done quite a bit of audio work to it, which makes this look really scary! If your Explorer is stock in the audio department, it will be pretty clean back there.)
The Transfer-Case Shift Relay plug harness is gray; it’s located deeper down forward and to the left of the radio and has a plastic plug capping it off.
After removing the plug cap, plug in the Transfer-Case Shift Relay.
The next item to install is the replacement Generic Electronic Module (GEM). The V8 AWD Explorer came with a different GEM then the V6 4WD. Ford must have decided to use different GEMs because the AWD didn’t need the Control-Trac circuitry. In ‘98, Ford made three different GEMs for the Explorer, but only one of them is used with the 4WD V6 Explorer, making the choice obvious.
If this isn’t obvious to you, you need the GEM from a V6 4WD Explorer because is has the Control-Trac transfer-case.
This GEM module is what handles the control aspect of the Control-Trac shifting. It also controls various other electrical items in the truck including windshield wipers, interior/exterior lighting, suspension ride control, defrosters, etc. Knowing this, it is very important to get a GEM from the SAME YEAR Explorer you are doing the swap on, as many electrical items and their values have changed over the years. Trust me, I learned the hard way!
You will need to check with your Ford dealer parts department to find out what GEM you will need.
The GEM is directly to the left of the radio. Remove the two bottom screws and the four large electrical plugs on it, then lift up and to the right to remove.
Now with the new GEM and t-case shift relay in place, put the dash back together using the new radio bezel with the 4WD controls on it. DUH!
The electrical plug for the 4WD switch was the one that was plugged onto the back of your original bezel into a “dummy” plug. That plug goes into your “real” 4WD switch.
Lastly, you need to get power to the transfer case shift relay circuitry and the neutral input from the transmission to the GEM. Ford used a different wiring harness in the engine compartment between its V6 and V8 models. Because of that, the power wire that feeds the shift circuitry and the neutral input lead that feeds the GEM dead end at the plug harness in the firewall. To keep this as “factoryish” as I could, I decided to add the appropriate pins to the engine side of the plug harnesses and install the maxi-fuse in the designated spot in the fuse box instead of running new wires and tapping into the harness.
The plug harnesses are called C147 (shift power lead) and C148 (neutral lead) and are located to the right on the power brake booster in the engine compartment on the firewall.
I got some plug pins that go in to the C147 and C148 at the Ford dealership. They didn’t have any part numbers for these pins but they look like this. You need to get one large pin and one small pin. These get added to your existing plug harnesses.
On C147 for the power to the transfer-case shift relay, you need to find pin #5 (its written on the plastic) and push the plastic filler out.
Now that you have a hole punched through, remove the white pin retainer clip on the inside of the plug, with a needlenose pliers.
Now take the large plug pin and insert it in through the back of the plug and reinstall the pin retainer clip.
Plug C147 should look like this when finished.
Now move on to plug C148. This pin is for the neutral lead. Find pin #26 and follow the same procedure you did with C147, except use the small plug pin.
Now that you have these connectors finished, you need to get fused power to the C147 lead and get the C148 lead connected into the transmission.
Again, for C147 I wanted to keep it “factoryish”. So I added a “Maxi” type fuse to slot #6 in the under hood Maxi-fuse box. Of course, this happens to be where the fuse is supposed to be for the t-case shifting power.
If you look into the fuse slot you will notice that the metal connections the fuse needs are not there, so you need to get some more funny-looking connectors from your Ford dealership.
Take the bottom of the maxi-fuse box off to insert these plugs. You will need to pry up the metal power distribution grid to access the appropriate fuse slots.
These are the slots you need to insert the fuse connectors.
With the grid pried up, insert both fuse plug inserts into the corresponding slots.
When inserting the fuse plug connector that goes under the power grid, just tape off the end of the wire with electrical tape and bend it over towards the other fuse plug to keep it out of the way of the power grid forks. The metal power grid has a fork blade that will push up and make a good contact with the fuse connector once you push the grid back into place.
This is what it will look like from on top with both fuse connectors in their appropriate spots.
Don’t forget to add a 20 amp maxi fuse!
The other lead (the one not touching the power grid) from the fuse insert needs to get tied in to the C147 plug pin connector lead. You will need about 3 feet of 12 or 16-gauge wire to make the connection.
Now move on to the neutral lead connection.
Under the hood, look for a large electrical connector located on the firewall right above the engine’s air plenum.
On the left side of this plug, look for a red wire with a white stripe. This wire goes into pin#9 (be aware that there is more than one wire this color in this plug harness, so LOOK AT PIN #s!). This is the neutral ground lead that comes from the transmission. This is the closest spot to access this wire. Before soldering, check and make sure you have the right wire with your multi-meter. Place the transmission in neutral, put one of the multi-meter’s probes on a good ground the other on the wire, then check for continuity. The meter should beep with the transmission in neutral.
You need to strip back its insulation and solder on an extension wire from here to go to the C148 pin plug lead.
That’s it for the electrical portion of the swap.
As I said before, you will need to pull out your transmission to have the new output shaft installed. Taking out transfer-cases and transmissions has been done before, so I’ll skip over those procedures.
After removing your transmission, take it to a transmission shop and have them install the new output shaft. I got it done for $150. I bought a 4R70W shop manual so I could attempt to do this install myself, but was scared off by seeing all the exotic tools that are needed to disassemble/reassemble this transmission. Not to mention all the little parts.
Here’s my transmission before the new output shaft was installed with the OEM 6-bolt adapter (bottom) and the new 5-bolt AA adapter (top).
As you can tell, the AA adapter is about an inch shorter than the stock one. Because of this, you need to get your rear drive shaft lengthened one inch, and the front drive shaft shortened one inch. I got away without doing any modifications to the front drive shaft because I had a different shaft made for the front when I installed the suspension lift, so the slip yoke had plenty of travel in either direction. If your drive shaft is stock, you will more than likely need to have it shortened.
Here is the AWD transfer-case (left) next to the Control-Trac transfer-case (right).
You can see, size-wise, they are not that different.
After getting the transmission with the new output shaft back from the shop, but before you bolt on the t-case with the 4WD adapter, you will need to mill down some of the aluminum that makes up the oil catcher inside the AA adapter to get the transfer case to bolt up cleanly. I was surprised I had to do this. My guess is that since this adapter is technically made for the B/W 1350/1354, there must be a slight difference in the castings between the Borg/Warner 1350/1354 and the Borg/Warner 4405 Control-Trac. Not a big deal though.
This part is a kind of a big deal. I was a little disappointed to read in one of the inserts with the directions for the AA Adapter that if you are doing this swap on a 1988 or newer AODE (4R70W) you will need to shave about a ¼-inch off the end of the input spline socket on the transfer-case. So much for just bolting it on! The reason this socket spline needs to be trimmed down is because at its current length, when the transmission’s output shaft is inserted in the t-case spline socket, the t-case’s socket will bottom out on the transmission’s output shaft where it begins to taper to a larger diameter, causing driveline bearing preload.
I used my pneumatic cut-off wheel and carefully and evenly cut down the ¼-inch that was needed.
This is what it looks like all together with the new adapter and t-case.
Reinstall your transmission with the t-case off but leave the AA adapter on the transmission.
Once the transmission is reinstalled, install the transfer-case BEFORE installing the transmission crossmember. If you install the crossmember and isolator first, you won’t be able to get the bottom two bolts screwed into the transfer case because the transmission isolator will get in the way.
Two more things to modify, the V6 edition transmission crossmember isolator and the transmission crossmember.
The reason for using the V6 isolator is because it is taller than the V8 isolator and since the AA adaptor was designed to be used with a taller crossmember isolator it works perfectly. The transmission crossmember isolator needs to have three notches cut into it to avoid some of the bolt heads it mounts close to.
Here you can see the height difference between the two isolators. V8 (left) V6 (right)
Here are the modifications I made to the isolator.
With the t-case bolted in and torqued down, you can now bolt on the transmission crossmember isolator. Once the isolator is in, line up the crossmember with the studs on the isolator.
I needed to extend the slots forward an inch on my crossmember to get the isolator studs to pass through it.
Now with the transmission crossmember isolator studs passing through the crossmember, finish bolting up the crossmember to the frame.
Reinstall your front and rear driveshafts and check your clearances.
Take the plug harness that is dangling by your new Control-Trac t-case and plug it into the t-case’s wiring harness.
Now go out for a test drive and check to make sure everything is working properly and not making any funny noises.
Helpful Hint: To shift into low range you must be in neutral and have the brake applied, then wait for your 4WD Low dash light to come on.
That’s it! Happy Wheeling!
Parts & Costs Overview………..
-Borg/Warner 4405 Transfer Case(Used) $350 w/shipping
-Advanced Adapters 50-8405 AODE(4R70W) to B/W 1350/54
4WD Transfer Case Adapter with 25 spline output shaft $500
-Radio Bezel with 4WD switch, Torque-on-Demand Relay,
and Transfer Case Shift Relay (from salvage) $50
-Generic Electronic Module (GEM) for Control-Trac (from salvage) $50
-C200 to Transfer Case wire harness (from salvage) $20
-Plug harness pin inserts (no part #s) $0
-Fuse connector inserts (no part #s) $0
-20 Amp Maxi-Fuse $2
-Transmission Crossmember Isolator (part#F87Z-6068-KA) $25
-Labor for Transmission Output Shaft Install $150
-Transmission Jack Rental $25
-Transmission-to-4WD Adapter Gasket $10
-4WD Adapter-to-Transfer Case Gasket $20
-Transmission Fluid (synthetic) $35
-Rear Drive Shaft Lengthening $125
-Front Drive Shaft Shortening $75 (quote)
Grand Total $1437
