Transfer Case Chain
Cross Reference Chart

Ordering a transfer case chain by "fits my truck" is how people end up with a chain that is one link short sitting on the bench next to a case that has been split for three days. The same vehicle can carry two or three different cases depending on trim, transmission and year, and some cases changed chains mid-run. The number that actually matters is the chain number, usually an HV (Morse Hy-Vo) designation, and the two things that confirm it are the tag on the case and the old chain itself.

Below is the cross reference we use at the counter. It is organized by case model first, because the case is what the chain fits, not the badge on the tailgate.

Chain Cross Reference by Case Model

Two things jump out of that chart. First, the NP242 shows up with more than one chain number. That is normal; listings and production changes split these cases into sub-variants, and the case tag is what tells you which one you have. Second, the NP231 family has a 1-inch chain and a 1.25-inch chain both with 31 links. Link count alone does not make a match. Width does.

Read the Tag Before You Do Anything Else

The aluminum tag on the rear case half carries the model and assembly number. That is the fastest way to narrow the chain choice, and it is free. If the tag is painted over, scrape it gently. If it is gone entirely, cast numbers on the case halves and the shift pattern on the lever will still get you close. Our guide on how to identify your transfer case tag and numbers walks through where to look on each family.

One trap worth calling out: Jeeps, GM trucks and Dodges have all had cases swapped in by previous owners. A Grand Cherokee that left the factory with one case can easily be running a junkyard swap. Trust the tag on the case in front of you, not the VIN decoder.

How to Measure and Identify the Old Chain

Once the case is split and the chain is out, you can confirm the match in five minutes with a set of calipers.

• Count the links. Lay the chain flat, mark one pin with a paint pen, and count pins all the way around. Count twice. Miscounting by one is the most common ordering mistake we see.
• Measure width. Measure across the outside of the link plates, not the guide plates. This is what separates a 1-inch NP231 chain from a 1.25-inch BW1354-style chain.
• Measure pitch. Pin center to pin center. Measure across several pitches and divide for a more accurate number. The HV-072 for GM NP246/261/263 cases, for example, is listed at .375 pitch.
• Look for stamped numbers. Many OE Morse chains have an HV number or part number stamped on a link plate. Wipe the chain down with brake cleaner and check several plates under a light.

Do not measure stretch on a chain that is still wet and stacked in a pile. Hang it or lay it out straight. To judge wear, hold the chain on its side with the ends together and see how far it sags or bows sideways. A new chain barely flexes laterally. A worn one flops over like a rope. For more on reading wear, see transfer case chain stretch symptoms and replacement cost.

When a Chain Alone Is Not the Fix

A new chain is the right repair for a case that clunks on takeoff, bangs when you go from drive to reverse, or rattles at light throttle, and is otherwise healthy. It is the wrong repair if the chain was the victim and not the cause. Before you button up the case, look hard at these:

Case wall wear

A stretched chain slaps the inside of the case. On a lot of NP231 and NP242 cases you will find a polished or gouged track along the wall. A shallow witness mark is fine. If it has worn thin, or through, the case half is junk, and no chain will save it. Check the outside of the case for wet spots near that area before you pull it.

Oil pump

The mainshaft pump feeds the chain and bushings on most of these cases. A scored pump, a cracked pump housing or a pump that has been rubbing a groove into the rear half starves the chain. Replace the chain without fixing the pump and you will be back. Low fluid does the same thing, so check what came out of the drain plug. If it was dark, foamy or full of fuzz, read our transfer case fluid buyer's guide before refilling.

Sprockets

Look at the drive and driven sprocket teeth. Hooked or sharpened teeth will chew up a new chain fast. Sprockets are often part of the mainshaft or front output, which turns a chain job into a hard-parts job. Browse transfer case hard parts if you find damage.

Bearings and end play

If the front output shaft has radial play, the sprockets do not stay in line and the chain wears unevenly. A new chain on loose bearings is a short-lived repair. If you are splitting the case anyway, budget for bearings and seals.

Full-time and AWD cases

The NP247, NP246, NV125 and 4MATIC cases have clutch packs, viscous couplers or electronic controls on top of the chain. A noise or bind complaint on those can be a coupler or clutch issue that a chain will not touch. Diagnose before you order. The chain-drive vs gear-drive breakdown also explains why these cases are more sensitive to chain wear than a gear-drive case.

Model-Specific Chain Guides

If you already know your case, these go deeper on labor, cost and the parts that usually get replaced with the chain:

• NP231 transfer case chain replacement cost
• NP241 transfer case chain replacement cost
• NP242 transfer case chain replacement cost
• NP246 transfer case chain replacement cost
• NP273 transfer case chain replacement cost
• NV247 transfer case chain replacement cost

Bench Notes

• On most chain cases the chain comes out together with the mainshaft and front output sprocket. Do not try to pry it off one sprocket inside the case.
• Mark the chain orientation before removal if you plan to compare it to the new one side by side.
• Clean both case halves to bare aluminum, inspect the chain track on the wall, and do not pry at the seam.
• Fill with the fluid called out on the tag or in the owner's manual. Wrong fluid in an AWD case with a clutch pack causes binding that people blame on the new chain.
• Spin the outputs by hand before reinstalling. Any tight spot or tick means something is not seated.

FAQ

What does the HV number on a transfer case chain mean?

HV is the Morse Hy-Vo chain designation, and the number after it identifies a specific chain by pitch, width and link count. Aftermarket brands cross to the same HV number, so it is the most reliable way to match a replacement chain to your case.

Can I identify a transfer case chain without the case tag?

Yes. Count the links, measure the width across the side plates, and measure pitch from pin center to pin center. Compare those numbers to the listing for the HV number you think you need. If the tag is still on the case, read it first because it narrows the choice before you split anything.

Do NP231 and NP242 use the same chain?

Do not assume they do. The NP231 and NP233 share a chain family, while the NP242 is listed with its own chains such as HV-028 and HV-063. Match by the case tag and by counting links and measuring width on the old chain.

Should I replace the chain alone or rebuild the whole case?

A chain alone is fine on a case with a healthy oil pump, tight bearings and undamaged sprockets. If the chain has worn through the case wall, the pump is scored, or the sprocket teeth are hooked, a chain by itself will not last.