If you've started hearing a nasty grinding noise or feeling a weird shudder in your old Ford or Bronco, it might be time to pick up a borg warner 1356 rebuild kit before things get really ugly. This transfer case was a staple in Ford trucks from the mid-80s through the mid-90s, and while it's generally a workhorse, time and high mileage eventually catch up to even the toughest components. Whether you're driving an F-150, an F-250, or a classic Bronco, the BW1356 is likely the silent partner under your floorboards—until it stops being silent.
Why the Borg Warner 1356 Eventually Needs Some Love
The 1356 is a bit of an interesting beast because it uses a magnesium case rather than the heavier cast iron or aluminum seen in other models. This makes it lighter and pretty resistant to some types of wear, but it also means you have to be careful with it. Most of the time, a rebuild becomes necessary because of high mileage or a very specific design flaw that's well-known in the 4x4 community.
The biggest culprit is usually the oil pump. Inside the case, there's a little pump held in place by a notch in the casing. Over hundreds of thousands of miles, that pump can actually wear a hole right through the magnesium case or just slip out of place. When that happens, your internals don't get the lubrication they need, and suddenly you're looking for a borg warner 1356 rebuild kit to save what's left of your drivetrain.
What You'll Usually Find in a Rebuild Kit
When you go shopping for a kit, you'll notice they vary quite a bit in price and contents. A standard, high-quality kit should generally include all the essentials to get the job done right. You're looking for things like:
- Main Bearings: Usually from reputable brands like Koyo or Nachi.
- Gaskets and Seals: To stop that annoying red ATF from staining your driveway.
- Small Parts Kit: Think snap rings, washers, and those tiny bits that are easy to lose.
- Fork Pads: These are those little plastic or nylon pieces on the shift forks that wear down over time.
One thing to keep in mind is that most standard kits don't include the drive chain or the oil pump itself. If your case has been making a lot of noise, the chain is probably stretched out and slapping against the side of the housing. You'll want to inspect it and likely buy a new one separately.
Spotting the Signs of a Failing Transfer Case
You don't always need a full rebuild the second you hear a click, but there are some "red alerts" that suggest you should order that borg warner 1356 rebuild kit sooner rather than later.
The most common sign is a leak. If you see red fluid (ATF) dripping from the back of the transfer case, it's usually the output shaft seal. If you let that go, the case runs dry, and you're toast. Another big one is a "clunk" when you shift into 4WD or when you let off the gas. That's usually the chain showing its age. If the 4WD keeps popping out of gear, those fork pads we mentioned earlier are likely worn down to nothing, or the engagement teeth are rounded off.
The Famous Oil Pump "Stay" Problem
I mentioned this briefly, but it deserves its own section because it's the #1 reason these cases fail. The oil pump has a "tail" that sits in a groove in the case. Over time, that tail hammers away at the soft magnesium until it wears a hole or the pump starts spinning freely.
If you're doing a rebuild, don't just put it back together the way it was. Most guys will tell you to "fix" the oil pump stay while the case is open. You can find aftermarket brackets or even just weld a small piece of steel to reinforce that area. If you ignore this during your rebuild, you're basically just putting a countdown clock on your "new" transfer case.
Is This a DIY Job for the Weekend Warrior?
Actually, yes. Compared to an automatic transmission, which looks like a brain made of metal and springs, a Borg Warner 1356 is relatively straightforward. If you have a decent set of tools—especially a good pair of snap ring pliers—you can tackle this in a garage.
The hardest part is usually just getting the heavy thing out of the truck. It's not exceptionally heavy since it's magnesium, but it's awkward. Once it's on the workbench, it's just a matter of splitting the cases and keeping track of where everything goes. I always suggest taking about fifty more photos than you think you need. You'll thank yourself later when you're trying to remember which way that one specific washer was facing.
Essential Tools for the Job
If you're diving in, make sure you have: 1. Quality Snap Ring Pliers: Don't buy the cheap ones; you'll just end up frustrated and bleeding from the knuckles. 2. A Clean Workspace: Magnesium cases hate dirt, and you don't want grit getting into your new bearings. 3. A Torque Wrench: Remember, magnesium is soft. If you "gorilla" the bolts back in, you're going to strip the threads, and then you've got a real headache.
Choosing the Right Kit
Not all kits are created equal. When searching for a borg warner 1356 rebuild kit, look for one that uses name-brand bearings. Cheap, unbranded bearings are a gamble you don't want to take when the labor involved is this high. Also, check if the kit is for a manual shift or an electric shift model. The internals are very similar, but there are small differences in the seals and certain components that can trip you up if you buy the wrong version.
The Chain and the Fluid
While you're in there with your borg warner 1356 rebuild kit, do yourself a favor and just replace the chain. Even if it looks "okay," a new chain is cheap insurance against having to pull the case again in six months. A stretched chain can eventually skip teeth, and that sounds like a machine gun going off under your seat.
And for the love of all things mechanical, use the right fluid. These cases take ATF (Automatic Transmission Fluid), not heavy 80W-90 gear oil. Using gear oil is a surefire way to kill the oil pump and ruin all that hard work you just did.
Wrapping Things Up
Rebuilding a transfer case might sound intimidating, but it's one of the most rewarding "big" jobs you can do on an old Ford. There's a certain satisfaction in knowing your 4WD is solid and won't fail you when you're out in the mud or snow. With a good borg warner 1356 rebuild kit and a Saturday afternoon, you can basically reset the clock on your truck's drivetrain.
It's way cheaper than buying a remanufactured unit, and let's be honest, you'll probably do a better job paying attention to the details than some assembly line would. Just take your time, fix that oil pump stay, and make sure everything is clean before you bolt it back together. Your truck—and your wallet—will definitely thank you.