Ford BW1356
Transfer Case Problems & Rebuild Cost

The Borg Warner 1356 is the aluminum, chain-driven, part-time transfer case Ford used in the late 1980s through the mid 1990s in F-150, F-250, F-350, and Bronco 4x4s. It came in two versions: a manual shift case with a floor lever and an electric shift version with a dash switch and a shift motor on the side of the case. It sits behind the C6, the E4OD, the Mazda M5OD, and the ZF5 depending on the truck.

The case is stamped 13-56 on the housing, and that matters. The 1354 and the later 4406 look similar from underneath but use different bearings and many different internals. Confirm the number on the case or the tag before you order a single part.

What Actually Fails

Shift Fork Pads

This is the classic 1356 failure. The mode fork rides on small plastic or nylon pads. When they wear through, the fork rubs metal-to-metal on the collar, the truck grinds going into 4WD, and eventually it will not stay engaged. Pull the case apart on a 1356 with 150,000 miles and you will usually find pads worn thin or missing. They are cheap; replace them on every rebuild whether they look bad or not.

Chain Stretch

Like every chain case, the 1356 chain grows with age. Symptoms are a clunk going into 4WD, slop on throttle changes, and in bad cases a slapping noise as the chain hits the case. A stretched chain also accelerates sprocket and bearing wear.

Oil Pump Wear

The 1356 relies on a small pump on the rear output to lubricate the rear end of the case. Low fluid or a worn pump starves the rear bearing and bushing. If the case has been run low, look hard at the pump housing and the rear output bearing.

Electric Shift Faults

On the electric shift version, a no-shift complaint is often not the case at all. The shift motor, the dash switch, a corroded connector at the case, or a failed module can all leave the truck stuck in 2WD or 4WD. Check power and ground at the motor connector before you condemn the case. The front hubs also have to engage — if the case shifts and the front axle does not drive, look at the hubs.

Output Seal Leaks and Cracked Ears

Front and rear output seals leak with age. Less common but worth checking: cracks at the mounting ears or around the front output on trucks that have had a bent driveshaft or a hard off-road life.

Symptoms to Match Against

• Grinding when shifting into 4WD, or will not stay in 4WD: fork pads first.
• Clunk on engagement and throttle changes: chain stretch.
• Whine that follows road speed: bearings, often from low fluid.
• Dash switch does nothing: electrical, motor, or module before internals.
• Wet case and crossmember: output seals, check the yoke surfaces too.

For a wider walk-through, see how to diagnose a bad transfer case.

Inspect Before You Buy Parts

Drain the fluid first. Bits of black or white plastic in the pan are fork pad material — that tells you right away what you are dealing with. Heavy glitter means the chain and sprockets have been grinding. Spin the front output in neutral to feel for chain slack, and rock the rear yoke up and down to check the tail bushing.

When the case is split, look at:

• The fork and collar. If the fork has worn grooves into the shift collar, replace the collar too.
• Case halves. Chain contact marks, cracks near bolt bosses, and the condition of the bearing bores.
• Planetary. Low range uses a planetary set; chipped teeth or a loose carrier mean low range will not last.
• Pump. Scoring on the pump body or gears.

The Parts You Actually Need

The Ford BW1356 transfer case rebuild bearing and seal kit (BK1356) includes the case bearings, all the external and internal seals, the gaskets, and the inserts, with Nachi and Koyo bearings. It covers both the electric and manual shift 1356. It does not include the chain, sprockets, planetary, or fork pads, so budget for pads every time and a chain if yours has slack.

Refill with Mercon-type ATF. If a previous owner filled it with gear oil, flush it out — the pump and the pads were not designed for it. Our transfer case fluid guide has more on matching fluid to the case.

Failure Mode Quick Reference

What It Costs

DIY: A full bearing kit, fork pads, a chain, and fluid usually land between $300 and $420. The rebuild is very doable on a bench. Plan for a puller, snap ring pliers, a seal driver set, and a clean work surface — the 1356 has a lot of small parts and the shift rail detent ball likes to escape.

Shop rebuild: Roughly $900 to $1,500 with removal and installation, more if the case needs to be swapped or the electric shift system needs diagnosis on top of the rebuild.

Used case: Cheap, but every 1356 in a junkyard is just as old as yours and probably has the same worn pads and long chain. If you go used, plan on opening it up and doing pads and seals before it goes in.

FAQ

How do I tell a BW1356 from a 1354 or a 4406?

Look for 13-56 cast or stamped into the case, or check the tag on the case. The 1354 was mostly used in Rangers and Explorers, and the 4406 replaced the 1356 in later F-series trucks. They look alike from underneath but take different bearings.

Why does my 1356 grind when I shift into four wheel drive?

The most common cause is worn shift fork pads. When the pads wear through, the fork rubs the shift collar and the case grinds and may not stay engaged. Fork pads are cheap and should be replaced on every rebuild.

What fluid goes in a Borg Warner 1356?

Ford specified Mercon-type automatic transmission fluid. Fill to the bottom of the fill plug hole with the truck level. Avoid gear oil; the pump and fork pads were designed around ATF.

Does the BK1356 kit include the chain and fork pads?

No. The kit covers bearings, seals, gaskets, and inserts. Inspect and replace the chain, sprockets, planetary, and fork pads separately as needed.