S&S Cycle Crankcases — 1999-2006 Harley-Davidson

S&S Cycle crankcase for 1999–2006 Harley-Davidson Twin Cam 88A engines (excluding 2006 Dyna models), featuring a reinforced 4-1/8" wrinkle-black case with extra-large front motor mounts and oversized cam chest for high-lift cams. Kit includes the crankcase, breather reed valve, pinion shaft, Timken bearings, and all mounting hardware.

Features

• Extra-large front motor mount for increased strength
• Oversized cam chest allows up to .675" cam lift without clearancing
• Timken-style sprocket shaft bearings for demanding applications
• S&S breather reed valve eliminates oil carry-over and scavenging problems
• Stock stud pattern for direct installation
• Wrinkle-black finish

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 31-0181A
• Case Finish: Wrinkle black
• Case Size: 4-1/8 inch
• Weight: 33.2 lb
• Category: Engine Components / Crankshafts

Fitment

Fits 1999–2006 Harley-Davidson Twin Cam 88A engines. Not compatible with 2006 Dyna models.

Frequently Asked Questions

Will this fit my 2006 Dyna?

No — this crankcase is not compatible with 2006 Dyna models. Standard 1999–2005 Dyna and Touring models will fit.

What's included in the kit?

Crankcase, S&S breather reed valve, pinion shaft, Timken bearing, and all mounting hardware needed for installation.

Can I use this with high-lift camshafts?

Yes — the oversized cam chest allows camshaft lift up to .675 inches without additional clearancing.

Is this stronger than the stock crankcase?

Yes — S&S reinforces the case with extra-large front motor mounts and upgraded Timken bearings for increased durability.