Cummins 3936256 — Genuine Timing Gear Case Housing

MPN: 3936256  |  Also Known As: gear housing, timing case housing, front gear case

Restore factory alignment and sealing at the front of your B-series. The genuine Cummins 3936256 timing gear case housing is a direct-fit OE replacement for 1994–1998 Ram 2500/3500 5.9L 12-valve (P7100). Built to Cummins specs for flange flatness, geartrain clearance, and long-term durability.

Features & Benefits

• OE geometry for correct gear mesh and front accessory alignment.
• Direct-fit housing for ’94–’98 5.9L 12V P-pump applications.
• Improves sealing when paired with new housing gasket and front crank seal.
• Durable casting to resist cracking and warping.
• Genuine Cummins quality and fitment.

Verified Fitment (Automotive)

Industrial/Off-Highway: Cummins lists 3936256 as a Gear Housing used primarily on Euro 2 / B-series 5.9L engines—verify by ESN for non-automotive equipment.

Specifications

• Type: Timing gear case / front gear housing
• OE Part Number: 3936256
• Material: OE-grade cast housing
• Quantity Required: 1 per engine

Often Paired With

• Gear housing gasket: Cummins 3938156 (B-series housing-to-block seal)
• Front crankshaft seal kit: Cummins 3937111 (’89–’07 5.9L; includes installer)
• Killer Dowel Pin (KDP) repair kit: recommended on 12-valve builds during housing service

What’s In The Box

• (1) Genuine Cummins Timing Gear Case Housing (3936256)
• Gaskets/seals sold separately (see “Often Paired With”).

Installation Tips

• Thoroughly clean block and housing surfaces; dry fit to confirm dowel alignment.
• Use a new housing gasket (3938156) and apply sealant only where Cummins specifies.
• Install a new front crank seal (3937111); verify crank hub/balancer torque.
• After first warm-up, recheck for seepage at corners and around the crank seal.

FAQ

WILL THIS FIT MY 1994–1998 12-VALVE RAM?

Yes—3936256 is the OE timing gear case housing for 1994–1998 Ram 2500/3500 5.9L 12-valve (P7100).

DOES THIS INCLUDE THE GASKET AND FRONT SEAL?

No—order gasket 3938156 and front crank seal kit 3937111 separately for a leak-free install.

DOES THIS FIT 1989–1993 OR 1998.5–2002 24-VALVE?

Not directly. Those engines use different housings. Some P-pump conversion builds may use 3936256—verify your conversion kit.

SHOULD I DO THE “KDP” FIX WHILE I’M HERE?

It’s smart insurance on 12-valve engines. A KDP (Killer Dowel Pin) repair kit prevents a locating pin from backing out and damaging the geartrain.

IS THIS A GENUINE CUMMINS PART?

Yes—OE Cummins 3936256.