Alto 023801B Hurth 71C/72C Marine Transmission Gasket & Seal Kit

Alto 023801B — Hurth 71C/72C Marine Transmission Gasket & Seal Kit

Alto 023801B is a gasket and seal kit for the Hurth HSW 71C and HSW 72C marine transmissions. The kit includes the seals, O-rings, and gaskets required for a complete overhaul or seal replacement on these units. Alto Products Corp. is a leading manufacturer of friction materials and transmission rebuild components for marine, automotive, and industrial applications. Note: Alto 023801B is the gasket/seal kit only — it does not include friction plates or steel separator plates. For the full overhaul kit for the Hurth HSW 150, see Alto 316803VB.

Confirm Fitment Before Ordering

Not sure this is the correct seal kit for your transmission? Contact us before ordering — have your transmission model designation and serial number ready from the data plate on the transmission housing. Our team can confirm the correct kit for your application by email, text, or live chat.

Part Specifications

• Alto Part Number: 023801B
• Application: Hurth HSW 71C and HSW 72C marine transmissions
• Kit Type: Gasket and seal kit (seals, O-rings, gaskets)
• Kit Contents: Seals, O-rings, and gaskets (verify exact contents against your transmission model and service manual)
• Vendor: Alto Products Corp.
• Note: Does not include friction plates or steel separator plates

Application Notes — Hurth HSW 71C / 72C Transmissions

• The Hurth HSW 71C and HSW 72C are hydraulically actuated marine transmissions commonly paired with smaller inboard gasoline and diesel engines. Verify your exact transmission model (71C vs. 72C) from the data plate before ordering.
• The 71C and 72C share a similar design family but may have differences in internal seal dimensions between sub-variants and production runs — confirm the correct kit against your transmission serial number and service manual.
• Hurth marine transmissions were later absorbed into the ZF product line. Service parts may be cross-referenced under either Hurth or ZF part numbers.
• Alto 023801B is the seal/gasket kit only. If friction plates or a complete rebuild kit are also required, contact us to identify the correct companion friction kit for the 71C/72C.
• Do not confuse Alto 023801B (71C/72C gasket & seal kit) with Alto 316803VB OEM cross-reference 023801DB, which is a separate kit for the Hurth HSW 150 transmission.

Related Alto Marine Transmission Kits

• Alto 316803VB — Hurth HSW 150 Marine Transmission Overhaul Kit
• Alto 316903VA — Hurth HBW150V Overhaul Kit
• Alto 316907AV — Master Transmission Overhaul Kit
• Alto 316807D — ZF Transmission & V-Drive Overhaul Kit

Installation Notes

• Verify transmission model and serial number from the data plate before installation — confirm correct seal kit against the transmission service manual
• Clean all mating surfaces thoroughly before installing new gaskets and seals — residue from old gaskets or sealant will cause leaks
• Lubricate new O-rings and lip seals with clean transmission fluid before installation to prevent tearing during assembly
• Replace all seals and O-rings in the kit regardless of apparent condition — do not reuse original seals during an overhaul
• Torque all fasteners to specification per the HSW 71C/72C service manual after seal replacement
• Use only the transmission fluid type specified by Hurth/ZF for the HSW 71C/72C when refilling after overhaul

Additional Information

• Vendor: Alto Products Corp.
• Part Number: 023801B
• Kit Contents: Seals, O-rings, gaskets

Frequently Asked Questions

Q: What transmissions does the Alto 023801B kit fit?
A: The 023801B is designed for the Hurth HSW 71C and HSW 72C marine transmissions. Contact us with your transmission model and serial number and we’ll confirm fitment by email, text, or live chat before you order.

Q: Does this kit include friction plates?
A: No — Alto 023801B is a gasket and seal kit only. It includes seals, O-rings, and gaskets but does not include friction plates or steel separator plates. Contact us if you also need the friction kit for the 71C/72C.

Q: Is 023801B the same as 023801DB?
A: No — these are different part numbers. Alto 023801B is the gasket and seal kit for the Hurth HSW 71C/72C. The 023801DB reference is associated with the Hurth HSW 150 transmission overhaul kit (Alto 316803VB). Confirm your transmission model before ordering.

Q: The kit shows out of stock — when will it be available?
A: Contact us by email, text, or live chat for current lead time and availability. We can advise on expected restock timing or identify an equivalent alternative if available.

Q: Is the Alto 023801B a direct OEM replacement?
A: Alto Products Corp. is a widely used OEM-equivalent supplier for marine and automotive transmission rebuild components. Alto seal kits are designed to meet or exceed OEM performance requirements in normal service conditions.