Lower Unit Seal Kit with O-Ring 91252-ZV5-003 for Honda BF35A BF40A BF45A BF50A
Lower Unit Seal Kit with O-Ring 91252-ZV5-003 for Honda BF35A BF40A BF45A BF50A
Product Overview
Lower unit seal kit for the Honda BF35A, BF40A, BF45A and BF50A outboards, the full gearcase seal set for the 35 to 50 HP four stroke Honda range. It carries two propeller shaft oil seals 91252-ZV5-003 and the O-ring seal 91351-ZV5-003, plus three drain and fill plug gaskets and the propeller nut cotter pin.
These four models share a gearcase, so one kit covers the 35, 40, 45 and 50 HP versions. That is useful if you run more than one Honda, or if you are not sure which badge your engine carries, because the seals are the same either way.
The propeller shaft oil seal is the one that fails. Fishing line gets behind the propeller, cuts the lip, and the gear oil starts taking on water. On these engines the gear oil goes milky long before the level drops enough to notice, so by the time it shows on the dipstick the gears have been running in an emulsion.
The kit is for one gearcase. Two oil seals, one O-ring, three plug gaskets and one cotter pin is everything the lower unit needs for a reseal.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Lower unit seal kit |
| Oil Seal | Honda 91252-ZV5-003, TC 22 x 35 x 7 mm |
| O-Ring Seal | Honda 91351-ZV5-003, 5.7 mm section, 76 mm outside diameter |
| Drain And Fill Gaskets | Three supplied, 1.5 mm section, 10 mm outside diameter |
| Cotter Pin | One supplied, 4 x 40 mm, for the propeller nut |
| Fits | Honda BF35A, BF40A, BF45A and BF50A outboards |
| Engine Type | Four stroke |
| Horsepower Range | 35 HP to 50 HP |
| Parts In Pack | 7 pieces |
| Quantity | 1 kit |
| Net Weight | 40 g including packaging |
| Packaging Size | 150 x 180 x 40 mm |
| Packaging | Pack |
| Warranty | 3 year |
OEM Cross Reference
| Component | Honda Part Numbers |
|---|---|
| Propeller shaft oil seal | 91252-ZV5-003 |
| O-ring seal | 91351-ZV5-003 |
91252-ZV5-003 is the propeller shaft oil seal and the kit carries two of them. It is a TC type seal, 22 mm by 35 mm by 7 mm, and the lip goes towards the gear oil when it is fitted.
91351-ZV5-003 is the O-ring seal, 5.7 mm section by 76 mm outside diameter. It sits on the shift shaft housing and it is the other place water gets into these gearcases.
The three drain and fill plug gaskets and the cotter pin are in the kit as well. Their individual numbers are not published here, but they are the Honda parts for the same service, and the kit carries three gaskets and one cotter pin.
Compatible Engines
| Model | Horsepower | Engine |
|---|---|---|
| BF35A | 35 HP | Four stroke |
| BF40A | 40 HP | Four stroke |
| BF45A | 45 HP | Four stroke |
| BF50A | 50 HP | Four stroke |
Four models on one gearcase, all four stroke. The BF45A and the BF50A are the same block at different ratings, and the BF35A and BF40A are the smaller pair, but they share the lower unit seals in this kit.
The listing gives model names only. It does not give model years and it does not give serial number ranges, and it asks you to verify fitment against your model or serial number without giving you a range to check. Honda built these models over a long run and changed seal arrangements on some of them, so send us the model and the serial number off the transom bracket and we will check the kit against it before it ships.
These are the four stroke engines. The Honda two stroke range uses different seals and is not covered by this kit.
What's Included
| Component | Part | Qty |
|---|---|---|
| Propeller shaft oil seal, 22 x 35 x 7 mm | Honda 91252-ZV5-003 | 2 |
| O-ring seal, 5.7 x 76 mm | Honda 91351-ZV5-003 | 1 |
| Drain and fill plug gasket, 1.5 x 10 mm | Included | 3 |
| Cotter pin, 4 x 40 mm | Included | 1 |
Seven pieces, which is the whole lower unit seal set for one gearcase on these four models.
Key Features
| Feature | Detail |
|---|---|
| Oil seal 91252-ZV5-003 | Two in the kit, TC 22 mm x 35 mm x 7 mm |
| O-ring seal 91351-ZV5-003 | Shift shaft O-ring, 76 mm outside diameter |
| Complete reseal | Two oil seals, one O-ring, three plug gaskets, one cotter pin |
| BF35A to BF50A | The four models that share this gearcase |
| Four stroke Honda | The 35, 40, 45 and 50 HP four stroke range |
| One gearcase | Everything for a single lower unit service |
Signs The Lower Unit Needs Resealing
| What You See | What It Means | Action |
|---|---|---|
| Gear oil turns milky | Water past the propeller shaft oil seal | Fit the kit and pressure test the case |
| Oil on the propeller or the skeg | Oil seal lip cut or worn | Fit the kit |
| Fishing line behind the propeller | Line cutting the seal lip | Fit the kit before the seal fails |
| Gear oil level dropping between services | Seal already leaking | Fit the kit and check the gears before refilling |
| Propeller nut without a split pin | Cotter pin missing or broken | Fit a new cotter pin |
| Drain plug gaskets flattened or reused | Crush washers spent | Fit new gaskets at every oil change |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the model against the table above, four stroke only |
| 2 | Drain the gear oil and look at it, milky oil means the seal has already gone |
| 3 | Take the propeller off and check for line behind it |
| 4 | Prise the old oil seals out without scoring the bore |
| 5 | Clean the seal bores and check them for corrosion and scoring |
| 6 | Fit the new seals square, lip facing the oil, with a little grease on the lip |
| 7 | Fit the new O-ring on the shift shaft housing |
| 8 | Fit the three plug gaskets, refill with gear lube and fit the cotter pin through the propeller nut |
| 9 | Run the engine in a tank, then check the gearcase for leaks after it has cooled |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | 3 year |
| Packaging | Pack |
Before You Buy
- Lower unit seal kit for the Honda BF35A, BF40A, BF45A and BF50A outboards
- Propeller shaft oil seal 91252-ZV5-003, two supplied, 22 mm x 35 mm x 7 mm
- O-ring seal 91351-ZV5-003, 5.7 mm x 76 mm
- Three drain plug gaskets and a 4 x 40 mm cotter pin in the kit
- Seven pieces, the full lower unit set for one gearcase
- Send us your model and serial number and we will check the kit first
- 40 g with packaging, box 150 mm x 180 mm x 40 mm
- 30-Day Easy Returns
- Free Worldwide Shipping
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Before You Buy
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