Tag np205

If you ignore the fact that one of these is an F-150 and the other is a Bronco, then these two trucks are almost identical. They both run the trusty 300 inline 6. They both have an NP435 four-speed transmission. And of course, they both wear that classic bullnose style. But other than the model and the paint color, there is one pretty big difference. The Bronco has four-wheel drive. Howdy, folks. Ed here. Welcome back to Bullnose Garage. Four-wheel drive is one of those topics that can divide truck guys. Some folks will tell you that a truck without 4×4 is just a car with a bed. Others have never even needed it, let alone actually put a truck in four-wheel drive. But here’s the thing. Even if you’re in the first camp, the guys who swear by 4×4, do you actually know how the system works in an 80s era Ford? Ask any Ford guy what transfer case he’s running and you’ll either get a blank stare or a half-hour lecture. So today I’m going to save you the trouble of both. We’ll look at how the 4×4 system works in bullnose trucks, what transfer cases Ford used, how they differ, and how it all ties together with the hubs, the axles, and that floor shifter down by your right leg. And just to make it interesting, we’ll use my ’82 Bronco here as the guinea pig. It’s running a Borg Warner 1345 hooked up to an NP435 transmission. Even though the door tag says it should have been a T18. So somewhere along the way, this thing got a little surgery. You know, that’s half the fun of these old Fords. You never quite know what you got until you actually crawl under there and check it out. So, let’s check it out.

So, before we dig into transfer cases and all the details, let’s zoom out and look at the big picture of how four-wheel drive actually works on these bullnose trucks. Because it’s not just one part, it’s a whole system working together. In two-wheel drive, power runs from the engine into the transmission, through the output shaft, into the drive shaft, and straight back to the rear axle. Simple enough. You’re just pushing the truck with the back wheels. But when you add four-wheel drive into the mix, the transfer case gets involved. That’s the box hanging off the back of the transmission, and its whole job is to split the power. One output goes to the rear drive shaft like normal, and the other output sends power forward to the front drive shaft. The catch with these older trucks is that the front wheels aren’t always connected. And so, let me introduce you whippersnappers out there to the old school manual locking hubs. This means if you shift the transfer case into four high or four low, but don’t lock the hubs, well, the front drive shaft will spin, the differential will spin, and even the axle shafts inside the knuckles will spin. But the wheels themselves are just freewheeling. You’re not actually putting the front tires in 4×4 until those hubs are locked. Funny enough, you could technically just lock one hub and not the other. And this means that the rear axle is pushing and one front wheel is pulling and you’ve basically invented three-wheel drive. It’s not smart, but it is possible. And I guarantee a few people watching have probably done that. And because I know some keyboard warrior out there is going to call me out. Technically with open diffs, you only ever drive one tire per axle at a time, but you get the idea. The whole open versus lock diff thing is a rabbit hole of its own. Two-wheel drive, four-wheel drive, one-wheel peel, py lockers, but that’s a topic for another day. Anyway, so let’s talk transfer cases. This is the heart of the whole 4×4 system, and it’s what makes the magic happen. Ford gave us a few different options of the bullnose years depending on the truck and the year. The most common one you’re going to find is the Borg Warner 1345. That’s what’s in mine. It’s aluminum chain driven and it was the bread and butter of the F-150s and Broncos in the early to mid-80s. Lighter than the old cast iron monsters, but still tough enough for what most guys use these trucks for. It weighs about 85 to 90 lbs dry, handles enough torque for both those applications, and uses a 2.72 to 1 low range with a chain about an inch and a quarter wide. It’s plenty stout for a small block or a six-cylinder, but if you throw a big block or crazy torque at it, that chain, it’s eventually going to stretch. Another one that you’ll run into is a new process 208 aluminum case, also chain driven, and just a bit lighter duty than the Borg Warner, about 80 pounds with 2.61 to 1 low range. A lot of F-150s and Broncos had them and while they get the job done, the housing was just a little bit weaker. You drop one on a rock and you’ll find out real quick why a lot of guys like to swap them out. Now we go to the NP 205. It is the Brute. All cast iron gear driven, tip of the scales at about 140 lbs dry. It’s got a shallow 6 to 1 low range, but what it lacks in gear reduction it makes up for in sheer indestructibility. By the bullnose years, you weren’t likely to see one of those in a half-ton or a Bronco because they mostly lived in the F250s and 350s or they got swapped in later by guys who wanted bulletproof strength. These things will take a thousand ft-lbs of torque without even blinking, which is why rock crawlers and heavy haulers still hunt them down today. And finally, at the very beginning of the Bricknose era in 1987, you had the Borg Warner 1356, just a touch heavier than its brother with 2.69 to 1 low range. Think of it as the 1345’s bigger brother. Still chain driven, but beefed up for the next generation. And I’m mentioning here because even though it’s not a bullnose transfer case, it’s a potential swap in. So, quick note here on the difference between a chain driven case and a gear driven case. Gear-driven cases like the NP 205 are heavier, they’re noisy, and they’re pretty much indestructible because it’s just gears meshing together. Chain-driven cases like the 1345 or 208 are lighter, quieter.

The chain is always the weak link. You could stretch it, skip it, break it, and if you do, you’re dead in the water. It’s a classic trade-off: strength, weight, and durability versus refinement, manners, and everyday drivability. My ’82 Bronco has the Borg Warner 1345 transfer case. Down here on the floor, you have the shifter with four positions: two high, four high, neutral, and four low. In two high, you’re sending power straight back to the rear wheels. Shift into four high, and the front drive shaft gets engaged, putting you in four-wheel drive at a 1:1 ratio. Neutral disconnects everything, useful for flat towing or certain recovery situations. Ford included neutral as a true towing mode, with an internal pump that keeps things lubricated even when flat towed behind an RV. Four low is where things get serious, with a 2.72:1 reduction applied to both the front and rear drive shafts, increasing torque for crawling through tough terrain. My Bronco runs this 1345 behind an NP 435 four-speed, even though the door tag says it should have been a T18. Someone swapped it, but it doesn’t change how the transfer case works. With the NP 435’s ultra-low granny first gear, if I put the transmission in first and the transfer case in four low, the reduction multiplies to about an 18:1 overall reduction before hitting the axles. With my gears and 31-inch tires, that’s over a 60:1 final drive at the wheels. Translation: I can just about pull a freight train at 1 mph. Obviously, that doesn’t mean my Bronco could actually tow a freight train. The gearing gives control and torque multiplication, but the driveline parts are only so strong. Low range is built for crawling through tough terrain or easing a heavy trailer into place, not dragging half the Santa Fe railroad behind you. It’s a good way to understand the mechanical advantage these old Fords can give you. One thing I love about these old trucks is how simple the shifters are. No buttons, no electronics, just a lever on the floor. In my Bronco, this shifter goes straight into the Borg Warner 1345. It’s a mechanical linkage, so when I pull it, it physically moves the gears inside the transfer case. The pattern is simple: two high, four high, neutral, and four low. You feel it clunk into each position, and you know exactly where you’re at. It’s not the smoothest thing; sometimes you have to roll the truck a bit to get it to drop in, but that’s part of the character. It’s raw and mechanical, and you’re connected directly to what’s happening underneath. These old Borg Warner cases weren’t true shift-on-the-fly setups like newer trucks. The manual says you can slip it into four high while rolling real slow, maybe under 5 mph, but it can be rough. Four low is full stop only. Yank while moving, and you’ll quickly find out why replacement parts are hard to come by. Treat it like the old 40-year-old mechanical box that it is. Smooth, deliberate shifts will serve you well. Fast forward three decades, and my 2015 F-150 has a neat little knob on the dash and a digital readout that tells me I’m in four-wheel drive. It even shows how much power is going to each wheel. It’s super convenient, but it lacks the character and charm of that old-school floor shifter. With the old trucks, you feel the clunk, hear the gears, and know something mechanical just happened. It’s a whole different feeling. Let’s move up front because the transfer case is only half the story. This Bronco, like most bullnose F-150s and Broncos, is running a Dana 44 twin traction beam front axle. That’s Ford’s unique take on independent front suspension, with two beams that pivot in the middle and a differential offset to one side. Some people love it, some hate it, but it was Ford’s way of trying to give a smoother ride without going full independent. On the ends, you have the locking hubs. These are manual hubs, meaning if you want four-wheel drive, you have to hop out, grab the dial, and twist it from free to lock. That physically connects the wheel to the axle shaft. When the front drive shaft spins, the wheels spin with it. Leave it on free, and the front wheels just coast while everything else spins inside. Ford also offered automatic locking hubs starting in the early ’80s, especially with select shift automatics. They became more common by around ’83 or ’84 when automatics became more popular, especially on higher trim Broncos and F-150s. By ’85 and ’86, they were fairly common, though manuals were still available, and many trucks stuck with them. Mechanically, the difference is simple. Manual hubs are driver-controlled. You turn the dial on the hub, and that physically locks the wheel hub to the axle shaft with a set of splines and a clutch ring.

Once it’s locked, you’re connected. Period. Automatic hubs, on the other hand, use a cam spring setup inside the hub. When the axle shaft starts turning under power, the cam engages the clutch and locks the wheel to the shaft automatically. That sounds great, but the problem is that they rely on friction and movement to engage. If the system’s worn out or you’re in a tricky spot, sometimes they’ll flip, half engage, or not engage at all. That’s why a lot of guys today either swap back to manuals or wish they had. Manuals are dead simple. You lock them and you know you’re good. Since we’re talking about the Dana 44 twin traction beam, here’s a fun tidbit. Ford kept this design alive all the way into the ’90s. Some folks even argue that the basic concept is still alive in a lot of trucks today. A lot of people bash on it compared to a solid front axle, but the twin traction beam did what Ford wanted. It rode nicer on the highway, still gave you four-wheel drive off-road, and it’s become a hallmark of Ford trucks from that era. Love it or hate it, it is pure bullnose DNA. If you’re interested, I have a great video specifically about the twin I beam and twin traction beam setup on these trucks. Definitely go check that video out because it dives into all that information. Let’s tie it all together and actually go through the process of engaging four-wheel drive on this Bronco. First, I got the truck sitting in two-wheel drive. That means the transfer case is in two high, sending power straight back to the rear axle, and the hubs are set to free. In this state, the front drive shaft and the axle can spin around, but the wheels aren’t connected. Basically, just a rear-wheel drive truck. Now, let’s say I want four-wheel drive. Step one is to lock the hubs. Walk up to each front wheel, twist the dial from free to lock. Now those wheels are physically connected to the axle shaft. Step two is to hop back in the cab and move the transfer case shifter from two high into four high. At that point, the case engages the front drive shaft. Because the hubs are locked, the front wheels now get power. Congratulations. You’re officially in 4×4. You might be wondering what happens if you lock the hubs but leave the transfer case in two high. In that case, the front wheels spin the axle shafts, which spin the differential, which spins the front drive shaft, which spins the front gears inside the transfer case, but none of that’s actually engaged to the engine. All you’re really doing is turning a bunch of extra iron for no real reason. You’re adding wear, you’re adding drag, and you’re getting reduced fuel economy. On a bonus Ford, reduced fuel economy usually just means a little more terrible. Once you’re in 4×4, a couple things change in how the truck behaves. There’s no center differential in these part-time systems. That means the front and rear axles are locked together at the transfer case, spinning at the same speed. It’s great for traction in mud, snow, or dirt, but if you try to run on dry pavement, you’ll feel it bind up in the turns. That’s called driveline bind, and it’s why you should only use 4×4 on loose or slippery surfaces. Another thing to keep in mind, tire size and pressure matter. If your front and rear tires are mismatched even slightly, the transfer case is going to feel that difference and start fighting itself. If you push it hard enough, something’s going to give, usually a U-joint or a chain. Now that we’ve covered the basics of how it all works, let’s talk about some of the quirks, common issues, and things you want to stay on top of if you’re keeping one of these old Ford trucks on the road. First up, chain stretch. The Borg Warner 1345 and 1356 both use a chain to drive the front output, as does the NP208. Over time, that chain can stretch, especially if the truck’s been used hard in four low. You’ll know it’s happening when you start hearing a rattling or popping sound under load, almost like the chain is skipping teeth. If you ignore it, you’ll eventually be sitting in the mud with a whole lot of noise and no forward motion. Then there’s the case on the NP208. Easy transfer case for what it was, but the housing could be a weak point. They were pretty lightweight, but one smack on a rock or over-torque the mounting bolts and you could end up with a crack. Once that happens, you’re not fixing it with JB Weld. You’re just hunting for another case. Shift linkages are another wear item. After 40 years, the bushings get sloppy and you’ll feel it when the shifter doesn’t want to fully drop into gear or feels a little bit vague. Sometimes guys think the whole transfer case is shot, but really it’s just a linkage that needs a refresh. Don’t forget about seals. These cases can leak, and output shaft seals get tired. If you don’t keep an eye on them, you can run low on fluid. Speaking of fluid, here’s a critical one. The Borg Warner and new process chain-driven cases use ATF, automatic transmission fluid, not gear oil. The gear oil can ruin the internals. The NP205 is the exception. It’s gear-driven and it takes gear oil. Knowing what belongs in your case is step one. Regular fluid changes are cheap insurance. Ford called for around every 30,000 miles, but let’s be real, most of these trucks went decades without one. If you buy a bullnose and don’t know its history, draining and refilling the transfer case should probably be one of the first jobs on your list. On the axle side, keep an eye on the U-joints. If you hear clicking when turning in 4×4, that’s your sign they’re worn out. They’re cheap and easy to replace, but ignore them and you risk a failure that could take out a yoke or drive shaft. As for upgrades, there are a few no-brainers. If you have automatic hubs, swap back to manual.

Manuals, upgrade. That alone can save you some headaches. If you’re doing a Borg Warner 1345 or 1356 behind something making serious torque, you need to consider an upgraded heavy-duty chain. And if you’re building a hardcore off-roader, the NP 205 is still the king. Heavier, shallower, low range, but about as close to unbreakable as it gets. One last fun bit of trivia: some guys lock the hubs while driving in too high, especially in winter or muddy conditions, to avoid getting out of the cab to lock the wheels every time they get stuck. It adds a little drag, wear, and maybe knocks half a mile per gallon off fuel economy, but on a bullnose Ford getting 12 mpg anyway, who’s counting? That’s the rundown on how Ford’s four-wheel drive system worked back in the bullnose years. From the transfer cases, whether it’s the Borg Warner 1345 like mine, the NP 208, or the legendary NP 205, to the floor shifters, the hubs, and the D44 twin traction beam up front. It all comes together to give these trucks their character. Modern trucks have knobs on the dash, digital readouts, and fancy electronics do the thinking for you. Convenient, sure, but there’s something satisfying about pulling a lever, feeling it chunk into gear, and knowing those front wheels are locked in because you made it happen. Four-wheel drive isn’t just about getting unstuck. It’s about understanding how all the parts work together and respecting what these old trucks were built to do. They may not be the most efficient or the smoothest, but they’ve got a kind of honesty and mechanical charm you just don’t get anymore. That’s why I love working with them. For me, that’s what makes this ’82 Bronco and that F-150 special. It’s not just another truck. It’s a reminder of how Ford built 4x4s tough, simple, and ready for anything. Love them or hate them, bullnose Fords have their own DNA, and it’s alive every time you roll out of the driveway in two-wheel or four-wheel drive. So, there you have it. Everything I know or pretend to know about bullnose Ford 4×4 systems and transfer cases. If you have any questions, concerns, gripes, or got something wrong, drop it in the comments and let me know. As always, thanks so much for watching, and we will see you next time. She’s rough around the edges, but she’s doing fine. Tinker Moon’s garage. She’s considered divine. Thanks again for watching. We will see you next time.