4.3L mercruiser filter

[Alan F.]

I guess the filter used on these 4.3's has been the same forever since I have a 2004 model and it is still the Mercruiser 35-883702K from what i can tell anyhow. This is the short version right?
I have read that an ACPF52 is a replacement and it just so happens I have one that was from my Fiero GT. This is a long filter and I know it fits on fine but am wondering if it really is a suitable replacement to use. Is it as good as or better then the Merc and more importantly should i use it?

 

[Schmoe]

The PF52 is a good filter from AC/Delco. I've used them exclusively on my boat engine for years. It's a tried and tested model and very common. If you got one, use it. If you read some more at this site, you'll find out that a lot of filters are made by the same manufacturer. I believe Mercruiser is no different. The PF52 will serve you well.

 

[Alan F.]

After thinking about it I decided not to use the PF52. That thing was way old so I went and bought a WIX filter instead. Hopefully that is a good choice too! Thanks for the help. Now I need to tackle the stern drive fluid. I really am not sure how this is done. Have read and seen the vent and drain hole but adding fluid through the bottom hole seems impossible since it is low enough in viscosity to just run out again isn't it??? As you can tell I am a total rookie with the boat motor stuff but feel I can handle most mechanical stuff. Just need to git er done once!!!

 

[HEV]

To slow down the oil from flowing out of the lower fill hole, one you’ve pumped enough gear lube to express from the vent, go ahead and plug the vent, then quickly remove the filler from the fill hole. Plugging the vent will create a vacuum. You’ll only loose a tablespoon or two. You can always top up from the vent. The Wix will be just fine. They flow and filter well. This is what I use on my 5.0 Volvo Penta. I use the Wix 51061 or the 1061 Napa Gold (same filter).

 

[Alan F.]

OK I am getting the part about the refill now. I guess the part I don't get yet is that I have a resevoir in the engine compartment that holds the gear oil and am wondering why one doesn't fill at that point? Also will the resevoir empty out when I drain at the lower unit??

 

[Geoff]

You don't want to fill the lower unit from the resevoir in the engine compartment as air will get trapped in the lower unit and create a false full reading.

Also the resevoirs don't always drain completely, so you might think there is oil in there.

I use the AC PF52 or a cross from another manufacturer. Wix has good flow and boats don't operate in dirty conditions so flow is most important. The crappy little Mercruiser filter is new, the original ones on my '94 engine were similar to the PF52 in size.

 

[Schmoe]

I've actually filled via the reservior a couple of times and it works, if you got the time. What I mean is like at end of season, fill it up and check it once a month or so and add more when needed. It will fill, but it takes time. Just to be sure, pop off the vent hole and see if any comes out. That will relieve any air trapped below and tell you if this stuff is getting down to the lower unit.