Thought I'd post my experiences draining and refilling my v-drive. I have a PCM powertrain with a 1:1 transmission and a 1:1.48 v-drive, so if you have something different you'll likely have different details.
Required tools: Fluid extractor (I like the Mityvac 7400); 3/8ths square socket with ratchet and/or 3/8ths open end wrench; small funnel; small pouring container (I used a two-stroke measuring cup).
First of all: I used to wonder this in my early inboard days, and I still see this question posted occasionally, so here is the answer: YES, the transmission and the v-drive are separate units. The order, from the rear of the boat going forward, is engine -> transmission -> v-drive. As far as my PCM is concerned, each of the three units has its own separate lubrication system using completely different lubricants. The engine uses 15W-40 engine oil; the transmission uses Dexron ATF; and the v-drive, which we are discussing here, uses (in my case) manual transmission oil.
The lubricant recommended by the PCM service manual for my v-drive is "Mobiltrans SHC 50". Unfortunately, the only source I've found for this is in 55 gallon drums
. Since the v-drive holds about one quart, and is described as "maintenance free", 55 gallons is more than a lifetime supply.
To be completely honest, I called PCM about this and they claimed to sell this magic elixir in PCM-labeled quart bottles, but I'd have to order it through a dealer (since they don't stock it) and who knows how long that would take and how much it and shipping would cost.
So I did a bunch of cross-referencing and found that Mobiltrans SHC 50 is a 50 weight, full synthetic, manual transmission fluid. Mobil themselves markets a direct cross reference under the name "Mobil Delvac Manual Transmission Fluid 50" which is available in one gallon jugs. Nobody local carried this either, but it was available online for about $55 delivered. eBay and UPS to the rescue!
On to the actual drain/refill. First step: Place the bottle of new fluid in direct sunlight. You want to warm it up so this thick fluid flows easily.
The PCM v-drive has two small fill/drain plugs, one on each side of the top of the housing, that have square heads. If you have square sockets, they are 3/8ths. One of them was easily accessible; the other was blocked overhead by the incoming fresh water hose, so I couldn't use a ratchet and had to employ an open end wrench instead. You should remove both plugs because the fluid is thick and you want the air exchange to be free and easy. Clean the plug threads and the area around each hole on the housing so thread sealant, paint, etc. don't fall in.
Next, grab your fluid extractor (I like the Mityvac 7400) and find one of its hoses that will fit into the drain plug opening. I used the smallest hose so I could reach around at the bottom and get the last bit of fluid, but be forewarned: This makes the draining process take a long time. Pump the extractor to draw a vacuum and you should start seeing fluid work its way through the hose and into the pump chamber. It took me probably 30 minutes to extract one quart of fluid, occasionally having to pump the handle to keep the vacuum strong. When you start sucking air, fish around a bit - I found a couple of pockets and got more fluid out. Remove the hose, clean things up, and get the pump out of your way.
Next, pour about half a pint of new fluid into the pouring container. Insert the funnel into one of the drain/fill holes and start pouring in the new fluid. The reason for the separate pouring container is because space is a bit tight and gracefully handling a full gallon jug might be questionable. This also allowsyour to keep track of how much fluid you've already put in... the first three half-pints can be poured in a little quicker since there's no risk of overflow and spillage.
When it's time for the fourth half-pint, pour a bit more slowly and watch BOTH holes. Eventually you'll see fluid come to the top of at least one. Stop pouring and cleanly set everything aside. Then, grab the rotatable fitting on the front of the v-drive and rotate it by hand a few turns in each direction. This will distribute the new fluid around internally and allow trapped air to escape. My fluid level visibly dropped as I did this. Top off the fluid until it's right at the bottom of the hole threads.
Replace the hole plugs (a dab of thread sealant isn't a bad idea, but keep it off the first few threads). There's no spec for tightening, so I went "snug plus a bit". It's not a pressurized system so "tight" is fine. Wipe any drips, clean everything up, and take her for a test drive.
That's it. Pretty straightforward. Most people will probably never do this (PCM says you only ever need to "add" fluid to top it off) but I figured after ~360 hours of hard work with heavy ballast it wasn't a bad idea to freshen the lubricant.
Hope this helps someone!
Required tools: Fluid extractor (I like the Mityvac 7400); 3/8ths square socket with ratchet and/or 3/8ths open end wrench; small funnel; small pouring container (I used a two-stroke measuring cup).
First of all: I used to wonder this in my early inboard days, and I still see this question posted occasionally, so here is the answer: YES, the transmission and the v-drive are separate units. The order, from the rear of the boat going forward, is engine -> transmission -> v-drive. As far as my PCM is concerned, each of the three units has its own separate lubrication system using completely different lubricants. The engine uses 15W-40 engine oil; the transmission uses Dexron ATF; and the v-drive, which we are discussing here, uses (in my case) manual transmission oil.
The lubricant recommended by the PCM service manual for my v-drive is "Mobiltrans SHC 50". Unfortunately, the only source I've found for this is in 55 gallon drums
. Since the v-drive holds about one quart, and is described as "maintenance free", 55 gallons is more than a lifetime supply.To be completely honest, I called PCM about this and they claimed to sell this magic elixir in PCM-labeled quart bottles, but I'd have to order it through a dealer (since they don't stock it) and who knows how long that would take and how much it and shipping would cost.
So I did a bunch of cross-referencing and found that Mobiltrans SHC 50 is a 50 weight, full synthetic, manual transmission fluid. Mobil themselves markets a direct cross reference under the name "Mobil Delvac Manual Transmission Fluid 50" which is available in one gallon jugs. Nobody local carried this either, but it was available online for about $55 delivered. eBay and UPS to the rescue!
On to the actual drain/refill. First step: Place the bottle of new fluid in direct sunlight. You want to warm it up so this thick fluid flows easily.
The PCM v-drive has two small fill/drain plugs, one on each side of the top of the housing, that have square heads. If you have square sockets, they are 3/8ths. One of them was easily accessible; the other was blocked overhead by the incoming fresh water hose, so I couldn't use a ratchet and had to employ an open end wrench instead. You should remove both plugs because the fluid is thick and you want the air exchange to be free and easy. Clean the plug threads and the area around each hole on the housing so thread sealant, paint, etc. don't fall in.
Next, grab your fluid extractor (I like the Mityvac 7400) and find one of its hoses that will fit into the drain plug opening. I used the smallest hose so I could reach around at the bottom and get the last bit of fluid, but be forewarned: This makes the draining process take a long time. Pump the extractor to draw a vacuum and you should start seeing fluid work its way through the hose and into the pump chamber. It took me probably 30 minutes to extract one quart of fluid, occasionally having to pump the handle to keep the vacuum strong. When you start sucking air, fish around a bit - I found a couple of pockets and got more fluid out. Remove the hose, clean things up, and get the pump out of your way.
Next, pour about half a pint of new fluid into the pouring container. Insert the funnel into one of the drain/fill holes and start pouring in the new fluid. The reason for the separate pouring container is because space is a bit tight and gracefully handling a full gallon jug might be questionable. This also allowsyour to keep track of how much fluid you've already put in... the first three half-pints can be poured in a little quicker since there's no risk of overflow and spillage.
When it's time for the fourth half-pint, pour a bit more slowly and watch BOTH holes. Eventually you'll see fluid come to the top of at least one. Stop pouring and cleanly set everything aside. Then, grab the rotatable fitting on the front of the v-drive and rotate it by hand a few turns in each direction. This will distribute the new fluid around internally and allow trapped air to escape. My fluid level visibly dropped as I did this. Top off the fluid until it's right at the bottom of the hole threads.
Replace the hole plugs (a dab of thread sealant isn't a bad idea, but keep it off the first few threads). There's no spec for tightening, so I went "snug plus a bit". It's not a pressurized system so "tight" is fine. Wipe any drips, clean everything up, and take her for a test drive.
That's it. Pretty straightforward. Most people will probably never do this (PCM says you only ever need to "add" fluid to top it off) but I figured after ~360 hours of hard work with heavy ballast it wasn't a bad idea to freshen the lubricant.
Hope this helps someone!
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