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The black sheep 89 Bronco II

#1
Okay, so it's not really black but with all the jeeps on here my bronco II is the black sheep of the bunch. I just ordered a t-case doubler today and plan on making some major drivetrain changes so I figured I would start a build thread. But I want to start from the beginning. I originally bought the truck in the fall of '06 with the intentions of building a trail truck, but it quickly turned into a mud truck build. It originally was a 2wd 5-speed with a 2.9 v6. The day I got it, I took all that out. I built the 3-link front suspension for the dana 44 front, and swapped in a 9" rear both from an early bronco I had that had been rolled. I took all the wiring harness from the frame rail and put it inside the cab, I moved the fuel cell inside and built aluminum covers for the wheels and engine bay to keep the mud out. The drivetrain was basically the same as it is now, a small block ford 289, c6 trans with manual reverse vb and an np205 transfercase. If anyone went to Midstate mudd bogg from around 07-09 you've probably seen it before. Back then this is what it looked like
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#5
Thanks yall. So last year I joined the MidCarolina Jeepers and decided to turn the truck into the trail truck I was originally going to build.

The first major thing I did was to take off the carburetor and go to fuel injection. I'm in school now so everything was done on a budget. I had a wiring harness from an 88 Crown vic with a 5.0L, along with the TFI distributor and was originally planning to use the upper and lower intake from the car as well but found a '97 explorer intake at pull-a-part and decided to go that way. Apparently the explorer intakes are good for about a 15hp gain because they are the same internally as a cobra mustang. I also got the fuel rail, throttle body, injectors, and mass air flow sensor from the explorer. The crown vic harness however was a speed density based EFI strategy and I needed to convert that over to mass air flow. There are alot of articles about this on mustang forums, but basically you can switch around some wires at the computer connector, add the mass air flow harness and convert from speed density to mass air flow. So from here I bought a computer for the 89-93 fox body mustang from autozone which uses a MAF sensor. But I have a '65 289 block so there are no EGR passages, or any emissions on it, I also wanted to clean up the wiring harness so I removed all of the EGR, the air pump, the A/C circuit. But just removing all the emissions would throw codes in the computer, I also was planning on using the explorer mass airflow instead of the mustang one, which has a different transfer function so I had to buy a programmer for the computer. I ended up getting a quarterhorse programmer. This lets me connect to the ECM, turn off all the emissions, change the MAF transfer function, change the idle speed, change the O2 sensor delay for long tube headers, basically anything in the computer. So next I just had to add the high pressure fuel system, I kept the low pressure pump at the fuel cell, this pumps fuel up to the engine bay where I put a filter which also acts as an accumulator tank and from there I put the high pressure EFI pump, the fuel goes through the fuel rail then returns to the accumulator and the rest then returns from the accumulator back to the fuel cell. This way even with the low pressure pump off the truck will still run until the small accumulator is empty. I also had to add the O2 sensors in the collectors, they have to be on the top of the exhaust so they don't collect moisture which was a little difficult to weld the bungs in with the exhaust in the truck but just took a little time. All in all the EFI turned out great, the most expensive part was the braided stainless line and AN fittings.

The original harness and crown vic upper and low intake and distributor
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The explorer lower intake I used
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Putting the lower intake on
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This is the hardware part of the quarterhorse programmer
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It goes inside the ECM, before
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After
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This was the harness ready to go in
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And this is ready to run
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#7
So to update this to how the truck currently sits. The last thing I did was to cut down the lift by 4" and change the tires to 36" SX's. This was pretty simple to do since I built coil towers on the axle that I could just cut off 4". I also had to modify the track bar location on the frame and axle and added a bumpstop right on the top of the axle center section to keep it from hitting the frame.
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#8
Up next for the truck, I'm planning a transmission swap along with a adding a doubler. It's going to be an np435 trans with a strong box doubler and np205 transfercase. The doubler uses the planetary gearset from the borgwarner 1356 transfercase found in 80's-90's ford trucks and broncos. I thought about the np203/205 doubler since I have a 205 in it now but the 203 and 205 both have 2:1 gear ratios, the bw1356 has 2.69:1. That will give me the option of 2:1, 2:69:1, or 5.3:1. The strongbox has a 3-4 week lead time so i'm hoping to get it in the next few weeks. Last weekend I bought this bw1356 for the planetary.
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#10
looks good, can you cut out any of that old ttb crossmember to give you more uptravel?
Eventually I might take the whole crossmember out and build a smaller one from square tubing but for now it also holds the track bar bracket on the drivers side. If I move the track bar bracket over to the drivers side frame rail I'd need a trackbar similar to the jeep one that has the bend for clearance of the center section. With all those changes it was just easier to add the bump stop for now. I'll add a better picture of what it looks like, it's tight but it turned out pretty well.
 
#11
Eventually I might take the whole crossmember out and build a smaller one from square tubing but for now it also holds the track bar bracket on the drivers side. If I move the track bar bracket over to the drivers side frame rail I'd need a trackbar similar to the jeep one that has the bend for clearance of the center section. With all those changes it was just easier to add the bump stop for now. I'll add a better picture of what it looks like, it's tight but it turned out pretty well.
sounds like it works.
 
#12
Did some more work to the truck this weekend. Friday I got my np435 short shaft kit from Jed's machining. This replaces the ford transmission to transfer case adapter which is about 9" long with one that is about 2" long. The doubler is supposed to be about 8" so I'm hoping I won't have to do much driveshaft changes to fit the doubler. If everything works out the drivetrain will only be an inch or two longer than what I currently have. The short shaft kit comes with a shorter output shaft for the transmission so I put that in this weekend. I'm still waiting on the gasket set to finish it up.
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#14
Yeah for sure, I was kind of just lucky that I'm using the np435 cause its the only trans they make the short shaft kit for. I'm still waiting on the doubler to be shipped from Behemoth Drivetrains. I'm planning to have it all ready to go in once it gets here. The last big headache will be getting a hydraulic clutch setup working but I think I have a plan for it that will work.
 
#15
Finally got some more work done on my truck this weekend. I got the new output shaft in the np435 and got it all put back together and painted along with the bellhousing. I got the C6 trans, the transfer case, trans cooler, and shifter out of the truck. While I'm at it I decided to rebuild my transfercase cause the truck always had a noise during coasting that I think is the transfercase. I bought the rebuild kit from ebay for it. The rebuild was pretty simple but I found there is a small pin on the output shaft that keeps the thrust washers from rotating that was worn down so far that the thrust washer was still able to spin. That was the only small part not in the kit so I ordered some pins from Mcmaster carr so we'll see tomorrow if they'll work otherwise I'll tear into a spare transfercase I have.
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#16
So after two months I finally got my doubler from Behemoth Drivetrain. So in case anyone else has heard of this company or is thinking of buying a doubler from them, here's my review. Their basic kits are made to work with planetary gearsets from most common transfercases, mine is the BW1356, they also have kits for BW1350/1354 which were in rangers and explorers and NP231/241/271 just to get an idea of who might could use one. So the bad, the only bad thing I can say is that it's taken a long time to get in. I was originally told 30 days or less, it finally came in last friday which was a day before two months. Throughout I had been calling the owner Jacob and he was always easy to get in touch with but it seems to be still a one man operation. I was talking to him Friday and he said he's sold about 70 strong boxes so far. The strong box itself seems to be pretty good quality, it's all aluminum and he makes them with manual machines, although from talking to him he has a CNC machine he's setting up to use. I put it together Friday afternoon and everything went together fairly easily, it's pretty simple. So here's what it looks like

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Here with my planetary, ring gear and bearing from the bw1356
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The planetary and ring gear in the front half
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Final Assembly
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#17
More pictures

The other half of my doubler install was the short shaft kit for the 4speed I got from jeds machining. This let me keep the driveshafts about the same length, but I ended up having to cut .35" off the input shaft of the doubler because the planetary is moved 0.5" forward inside the doubler so the shaft sticks out more and with the short shaft in the transmission there was just a little too much shaft.

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I also finished rebuilding the transfercase
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And built a new transfercase mount from an old trackbar end
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#18
Last night I finished the truck enough to drive it back to columbia. I didn't really keep up with the pictures as I put the final pieces together but here's a few I took. So far, I'm loving the four speed. I can tell the auto was a big power loss, especially at low rpms. I'm hoping I'll see better fuel economy too, with the auto it was around 9.5 mpg.

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Got 3 out of 4 of my trucks running at the same time, pretty rare for me.
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