BW4493 Transfer Case Chain HV-055 for Hummer H3

This is the HV-055 drive chain that links the rear output shaft sprocket to the front output sprocket inside the BorgWarner 4493 transfer case used in the 2007-up Hummer H3. It is a 1.50 in wide Morse-style silent chain and cross-references to BW4493 and HV055. If your H3 case has been opened and the chain has slop you can see, this is the part that goes back in.

A stretched chain is the classic wear item in a chain-drive transfer case. The symptoms are a clunk or slap from under the truck when you go on and off the throttle in 4WD, a grinding or rattling noise that comes and goes with road speed, and in the worst cases a chain that has worn a groove through the inside of the case housing. A chain that has jumped a tooth will usually announce itself with a loud bang and no front drive. Catching it while the noise is still just a slap saves the case.

On the bench: drain the case, pull the rear output housing, and lift the chain off with both sprockets together so the shafts come out as one assembly. Check the sprocket teeth for hooking and the case half for chain-rub marks before the new chain goes in, and check the oil pump while it is apart since a pump that has quit is often what killed the old chain. Reassemble with fresh sealant on the case halves and refill with the fluid your owner's manual calls for.

Confirm the tag on your transfer case reads 4493 and compare the chain width to your old one before ordering. H3 models built before 2007 and the H3T should be verified against the case tag.