8M0124227 Exhaust Bellow — Fits MerCruiser Alpha One Gen I & II and Bravo sterndrives, Replaces 18654A1, 18654B1, 32734A3

8M0124227 Exhaust Bellow — Fits MerCruiser Alpha One Gen I & II and Bravo sterndrives, Replaces 18654A1, 18654B1, 32734A3

GHMarine exhaust bellow for the bell-housing seal on the transom — the large rubber boot between gimbal housing and bell housing. Replaces OEM 8M0124227 and legacy 18654A1, 18654B1, 32734A3. Fits compatible Alpha One Gen I & II and Bravo sterndrives when your drive serial and part number match the table below.

Ships as one exhaust bellow + two hose clamps. Marine bellows adhesive and expander tool (ref 91-45497A1) are sold separately.

Which bellow is this?

This is the rubber exhaust bellow at the bell housing on the transom. It seals the exhaust where it passes through the drive bracket. It is not the metal upper exhaust tube, the U-joint bellow, or the shift-cable bellow — those use different part numbers.

If you are not sure, pull the drive and look at the large rubber boot on the exhaust path at the bell housing — that is what this SKU replaces.

Signs yours is due

·       White smoke or louder exhaust at the stern at idle — the bell-housing exhaust seal may be cracked or pulling off the flange.

·       Water in the bilge near the transom after you run — check the large rubber boot between the gimbal housing and bell housing (this part).

·       Spring inspection: soft rubber, cuts, burnt areas inside the bellow, or rusty hose clamps — replace before the season, not after it fails on the water.

Will it fit my drive?

This replacement exhaust bellow is Compatible with MerCruiser Alpha One Gen I (1983–1990), Alpha One Gen II (1991–current), and Bravo I, II, & III models. Also fits MC-1, R, MR, Blackhawk, and Vazer drives. OEM 18654A1 was superseded by 8M0124227 (same bellow). Confirm your engine/drive band in the table below before you order.

OEM & swap numbers

Current OEM is 8M0124227 (same exhaust bellow as legacy 18654A1 / 32734A3). Aftermarket cross-refs below.

Wrong part? Read before you order

·       NOT for upper exhaust tube 32-44348T (different spot on the exhaust)

·       NOT for U-joint bellow 816431A1 (drive shaft area)

·       NOT for shift cable bellow (see SKU 17B1005)

·       NOT a full bellow kit — you get one exhaust bellow + 2 clamps only

What ships in the box

·       1 × Exhaust bellow (bell housing / transom seal)

·       2 × Hose clamps

Often ordered with the other transom boots

·       U-joint bellow Gen II / Vazer (816431A1) — GH SKU 17B1007; Gen I (60932A4) -GH SKU 17B1004; Shift bellow — 17B1005 · listings coming soon

·       Many shops install shift and U-joint boots first; put the exhaust bellow on last — it is the tightest fit.

·       This listing is exhaust-only — not a 3-bellow kit.

Install tips while the drive is off

Work in a ventilated area. If you are not comfortable removing the sterndrive, use a marine shop.

1. Remove sterndrive; loosen both clamps; pull off the old exhaust bellow.

2. Clean and roughen the gimbal and bell housing flanges; coat the inside of both bellow ends with marine bellows adhesive; let dry until not tacky (often 10–20 minutes).

3. Install the gimbal (transom) end first; tighten the clamp through the access holes.

4. Use a bellows expander tool (OEM ref 91-45497A1) on the bell-housing end; tighten the clamp. Do not use grease on the flange.

5. Reinstall the drive; run at idle on muffs; check for exhaust leaks or water spray at the transom.

FAQ

Will this fit my Alpha One or Bravo?

Bell-housing exhaust bellow only — not shift cable or U-joint boots. Replaces 8M0124227 / 18654A1 / 32734A3. Match your drive or transom serial to the table; horsepower alone is not enough.

What is in the box?

One exhaust bellow and two hose clamps. Bellows adhesive and expander tool 91-45497A1 are not included.

How is this different from the shift or U-joint bellow?

Shift boot = small cable boot at the gimbal. U-joint boot = drive shaft (816431A1). This SKU = large exhaust boot on the exhaust path only.

Please note

Aftermarket replacement part. Not affiliated with engine manufacturers named above. "Compatible with", "Replaces", and cross-ref numbers mean this part is built to work like the originals listed — always confirm fit with your drive serial number.