View Full Version : Running a full size T-case with a small block Ford swap.


rwenzing
Jan 29 2009, 07:53am
http://home.comcast.net/~rwenzing/Message_Center_and_Shifter_sm.jpg

When I started my V8 swap project, I was sure that I didn't want to include the single ratio, full time AWD transfer case that is used in the AWD version of the 5.0L Explorer. Instead, plans called for a manually shifted, 2-speed, part time 4WD transfer case similar to the one that came as factory equipment in my FX4 Level II.

An easy (but expensive) solution could have been to get a $500+ adapter kit from Advance Adapters to mate the 4R70W Explorer transmission to the stock Ranger case. The kit consists of a new extension housing and a shaft adapter that steps down from the 4R70W's 31 spline output shaft to match the smaller Ranger T/C spline. That would have also allowed the use of the factory Ranger driveshafts and the factory manual Ranger T/C shift linkage.

For my purposes, it seemed like a better idea to substitute a larger transfer case designed for the torque of a V8. Thanks to the guys on ExplorerForums who developed the BW4406 swap into their 5.0L Explorers :thumbsup: , I felt that I had the info I needed to use the larger T-case in my Ranger. So, I picked up a low miles manual Borg Warner 4406 case from a 2003 F150.

The 4406 bolts directly to the stock Explorer 4R70W AWD extension housing without modification but that's where the easy part ends. Swapping it into a Ranger adds a new dimension to the clearance issues.

First of all, near the transfer case, a Ranger frame is several inches narrower than a Gen2 Explorer frame. Then add the fact that the 4406 transfer case is absolutely huge compared to either the stock Ranger 2-speed case or the stock Explorer AWD case. It is nearly twice as long front to back and the main body sits about 4 inches rearward of where the main body of the Ranger case was. It is also much wider and would sit about 1/4" from the driver side frame rail if the stock 5.0L Ex mounts were used. Even worse, the forward U-joint of the rear driveshaft would end up being about a foot farther rearward as compared to the stock Ranger, putting it adjacent and very close to the nose of the fuel tank.

The solution to both clearance problems was to move the entire engine/transmission/transfer case 3/8" toward the passenger side. This was accomplished by welding up the engine plate holes and trans crossmember holes and repositioning them.

These photos show the results of using the modified mounts. There is still not a lot of room there but imagine how it would be using the stock mounting position - 3/8" closer!


Transfer case to frame rail clearance:
http://home.comcast.net/~rwenzing/bw4406_tc_frame_clearance_sm.jpg


Slip yoke flange to fuel tank clearance:
http://home.comcast.net/~rwenzing/bw4406_tc_tank_clearance_sm.jpg


This is the modified F150 shift linkage mounted to the Explorer transmission extension housing. To get some extra clearance, I reversed and rewelded a pin in the linkage and cut almost 3/4" off the factory mounting bosses on the extension housing. Then I drilled the holes deeper and retapped the 14mm threaded holes for 5/8" x 1 1/4" NC bolts. This mod improved the clearance from the F150 T-case linkage to the smaller Ranger transmission tunnel. Combined with the 3/8" powertrain offset, the mod moves the linkage and lever significantly inward on the transmission tunnel, keeping it from intruding any more than necessary into the driver's legroom.
http://home.comcast.net/~rwenzing/Shift_linkage_BW4406.jpg


Here is the F150 silicone inner boot that has been reshaped to fit the Ranger tunnel. The stock Level II shift arm too short by itself, so I made up an intermediate extension shaft from a piece of 3/4" drill rod.
http://home.comcast.net/~rwenzing/bw4406_tc_inner_boot_sm.jpg


F150 interior trim boot.
http://home.comcast.net/~rwenzing/bw4406_tc_outer_boot_sm.jpg


The shifter moved all the way rearward to the 4x4 Low position.
http://home.comcast.net/~rwenzing/bw4406_tc_low_range_sm.jpg


Center console from a junked 97 Mountaineer. It has been repainted satin black to match the rest of the interior.
http://home.comcast.net/~rwenzing/Message_Center_Console_sm.jpg


I repaired the broken console lid, then recovered it with black Naugahyde to match the newly painted console.
http://home.comcast.net/~rwenzing/console_lid_reupholstered_sm.jpg


The lower driver side of the console was heated and reshaped to clear the shifter boot and bezel.
http://home.comcast.net/~rwenzing/Message_Center_Console_and_shifter_sm.jpg


Shortened Ranger rear shaft and factory 2003 F150 front shaft:
http://home.comcast.net/~rwenzing/V8_driveshafts_sm.jpg


The internal factory Ranger slip yoke was cut off and a new fixed yoke welded in by a driveshaft specialist. Then a 2006 Expedition/Navigator slip yoke and new U-joint were added before the assembly was balanced.
http://home.comcast.net/~rwenzing/V8_driveshaft_shorten_sm.jpg


This is the conversion U-joint to match the F150 front driveshaft to the stock pinion flange on the Ranger's D35 front diff.
http://home.comcast.net/~rwenzing/V8_driveshaft_conversion_ujoint_sm.jpg


This conversion works great! The 4406 fits well, shifts well and has the strength to handle the torque of my blown small block. Even the stock Ranger 4x4 dash indicator lights work after wiring them to the switch on the 4406.

Everything combined - the shift linkage, conversion u-joint, slip yoke, j/y 4406 transfer case, j/y F150 front shaft and shortening of the Ranger rear shaft - still cost less then the AA 1354 conversion parts would have.

Many thanks to the guys on ExplorerForums (http://www.explorerforum.com) who pioneered the BW4406 mod for their 5.0 Explorers! Their experiences formed the basis for my Ranger swap. More info HERE (http://www.explorerforum.com/forums/showthread.php?t=166726).


http://memimage.cardomain.com/member_images/7/web/727000-727999/727284_121_full.jpg


Alternatives:

I chose the BW4406 because it is readily available, not too expensive and there are still some low mileage examples out there. Of course, there are many other F/S t-cases that can be used with a V8 swap. Ford, GM and Chrysler cases often use the same 6-bolt pattern to the transmission.

The main cases of the common Borg-Warner 1356 T/C used in many 96 and earlier F/S Fords are about the same size as the 4406 but probably do not have the rear housing that my 4406 has. This should help in RBV's with shorter wheelbases or tank clearance issues.

There are smaller F/S cases that could make installation easier. A few possibilities are the NP205, NP208 and Dana 20. Since some are from earlier trucks, they might be a little harder to find and may need a rebuild.

pinellas50
Jan 29 2009, 11:06am
Awsome write up! I'm going to add this to this sticky thread unless you have an objection to that.

http://www.rangerpowersports.com/forum/showthread.php?t=172714

fiskarb
Jan 29 2009, 11:56am
Good info, for sure.

Teddyzee
Jan 29 2009, 03:11pm
Excellent info and write up. Thanks for sharing.
Well written.

rwenzing
Jan 29 2009, 05:35pm
Awsome write up! I'm going to add this to this sticky thread unless you have an objection to that.

http://www.rangerpowersports.com/forum/showthread.php?t=172714No objection whatsoever.