Trans Fluid Change 101, BW Velvet Drives

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firstbase

Guru
Joined
Nov 6, 2016
Messages
1,644
Location
United States
Vessel Name
Black Eyed Susan
Vessel Make
Grand Banks 42' Classic
Sent oil and gear fluid out to Blackstone for a first analysis since I bought the boat. YEAH!!! One time results were about as perfect as someone could want. I know it is one snapshot in time but gives me a good baseline. The only thing that was pointed out on both engines was the insolubles level in both gears. They suggested I needed to change the fluid. OK, no problem.

I remember the previous owner saying that there was no sump or bottom drain on the Borg Warner Velvet Drives. He said to get as much out as you can and then refill. Take it out and go boating. Then change again when you get back in. This should get most of the old out and replaced with new.

Any other options to get it all at once? This process sound about right?
 
From my own research I have been told about two ways to change BW oil:
1. From the dip stick, not perfect, get what you can.
2. From oil hose to the oil cooler.

Did not tried it yet but I will have to do it in a near future.

L.
 
Thanks. Does one method allow you to get more fluid out than the other?
 
I'd go with the PO's advice. You will never get it all out. It's like a drain and fill service on a car transmission, where you're only replacing something.like 50% of the fluid. Dipstick extraction works as well as anything and is easy. On the 71/72 it's a big hole that you can stick just about any hose into.
 
Thanks Dave, I have that and the shop manual. There is a reference to a "drain plug" to use when changing fluid but I will be darned if I can find one in the drawings or real life.....anyone who has the BW Velvet Drives, how do you change yours?
 
I'd go with the PO's advice. You will never get it all out. It's like a drain and fill service on a car transmission, where you're only replacing something.like 50% of the fluid. Dipstick extraction works as well as anything and is easy. On the 71/72 it's a big hole that you can stick just about any hose into.

Thanks Jeff. Looks like the best way to go. Only way to go?!?!?
 
I'd go with the PO's advice. You will never get it all out. It's like a drain and fill service on a car transmission, where you're only replacing something.like 50% of the fluid. Dipstick extraction works as well as anything and is easy. On the 71/72 it's a big hole that you can stick just about any hose into.

Yes. Use the dipstick hole. I got one of those plastic pumps with 1/4" plastic hose, works great.
You'll get about 80 to 90% out, but don't worry so much.
I've only changed mine once in a long time, but the fluid looks like new.

The BW VD is probably the only thing on the boat you won't have to worry about.
 
If you look at figure 1 in the pdf youll see the fluid return port, its the lowest point and drains it well. Be sure to drain the cooler and both lines, or do what the PO said about draining and filling twice.

I use full synthetic tranny fluid as it has a lot higher temp capacity before coking.
 
On the 71 & 72C VD low down on the starboard side of the transmission case near the engine, is a large port. Depending on your application there is either a pipe plug screwed into it or an oil line connected to the port.

Mine has the plug and I can drain most of the oil from the port. My friends who have the oil line say it's a hassle to remove the oil line to drain the oil and use the dip stick tube method.
 
On the 71 & 72C VD low down on the starboard side of the transmission case near the engine, is a large port. Depending on your application there is either a pipe plug screwed into it or an oil line connected to the port.

Mine has the plug and I can drain most of the oil from the port. My friends who have the oil line say it's a hassle to remove the oil line to drain the oil and use the dip stick tube method.

You didn't mention exactly which VDs you have. Some keep more oil after a drain than others. Ive done it both ways and it's definitely much more of a hassle to remove the lower return line than it is to suck the oil out through the filler. I don't believe you can get any more out by removing the lower oil line. In addition, you always run the risk of causing a problem when removing and replacing the oil line.

Ken
 
All of the paperwork/manuals I have show these are 71-72 Series Model 10-14. I believe 2.1:1 ratio. Haven't confirmed anything from the plate but will as I am sure that will show the exacts. I understand transmissions less than I understand everything else.

I have the hose setup not a drain plug so will leave it alone and drain through the dipstick. Question, if I went with PO's advice and drained, filled and then drained again, is it necessary to use the transmission, put it in gear and boat for a few minutes to mix it up before draining again? Or, does simply running the engine in place mix it up by circulating it through the cooler?
 
All of the paperwork/manuals I have show these are 71-72 Series Model 10-14. I believe 2.1:1 ratio. Haven't confirmed anything from the plate but will as I am sure that will show the exacts. I understand transmissions less than I understand everything else.

I have the hose setup not a drain plug so will leave it alone and drain through the dipstick. Question, if I went with PO's advice and drained, filled and then drained again, is it necessary to use the transmission, put it in gear and boat for a few minutes to mix it up before draining again? Or, does simply running the engine in place mix it up by circulating it through the cooler?

If you have a model 10-14 (should be on the little plate near the dipstick) then you have a CR2 model of 72C. This is the heavier duty model of the "drop center" transmissions. The other model is the 10-13 which is based on the 71C which is a little bit lighter duty.

These are very good transmissions and there were many thousands made and still in use. I have 2 of the 10-13's myself.

Due to the "dropped" rear section you can only get a little more than 1/2 the oil out no mater what you do because a whole bunch of it sits in the lowered rear section which has no drain or access to get even a thin tube into.

Yes, you have to run it some between fills because what you're doing is diluting the old oil with the new and you need to run it in gear otherwise the gears in the rear section are not moving.

Ken
 
Thanks Ken. That matches what the previous owner told me exactly. I appreciate your confirming. Now I can change it out knowing I'm doing it the correct way for this model. I guess to really change it I would have to do it 3 or even 4 times but not sure that this would be worth the effort and cost.
 
Yeah it's probably not worth it unless you were trying to solve a specific problem like water in it
 
No water, just ".1% Insolubles" on the analysis. According to Blackstone that's not a huge amount or indicative of anything beyond time to change the fluid.

Is there anything I need to do before or while changing the fluid to get it down from the cooler or does it drain when the engine is shut down?

I believe the fluid should be changed while warm, after a run to heat it up correct? Change it, then go back out either that day or another time, and do the same when I get back in? Sorry for the ignorance. Just never done it before. Have read a lot and they all seem to vary depending on make and model.
 
I wouldnt sweat oil changes too much if the oil is still clear and brite, smells normal and isnt more than 5 years old.

Change as often as you like, every year is good, every 1000 hours on my experience as long as it good, that is OK....and that is a lot of experience on tow boat trannys.
 
Agree with above. .1% insolubles in not bad at all for a system that has no filter.

As far as changing, its better if the oil is a bit warm, more stuff is in suspension to get out.

The oil cooler usually drains itself as long as its higher than the transmission. Its not a lot of oil anyway.

BTW - do you have the real BW manual that tells you how to properly check the oil level?

Ken
 
Thanks ps. I have been going through the boat piece by piece trying to sort out where things are. Decided to change all fluids, flush the systems, etc. for my own piece of mind and to familiarize myself with things and learn how to do it. At least then I will know for sure what was done and when. I've been a little bit of a slave to the boat so far and need to get it out and use it for the reason I bought it. Will put trans fluid change on the back burner for now although it sounds sort of no brainer-ish. He says thereby absolutely insuring that it will be a fiasco for some reason. :)
 
Agree with above. .1% insolubles in not bad at all for a system that has no filter.

As far as changing, its better if the oil is a bit warm, more stuff is in suspension to get out.

The oil cooler usually drains itself as long as its higher than the transmission. Its not a lot of oil anyway.

BTW - do you have the real BW manual that tells you how to properly check the oil level?

Ken

Yes, I have read it. Mentions how to check and why it needs to be done warm. Gives some instruction on getting a level when cold. Is that what you are talking about?

My concern is that I could swear the PO told me that there was something odd about the trans. dipsticks. Something about one of them being different than the other. I look at them, they look the same to me. I know that the Ford Lehmans are odd and you have to change the dipstick to read correctly as the engine is at a slant. My FL dipsticks show very low oil but are not. Again, just to check everything out for myself, I wanted to get ALL of the oil out so I could pour in the approved amount and then see where it lands on the stick. Same with my transmissions. If they were empty then I could do the same and be assured a proper level. That's not going to happen with the Velvet Drives. Just have to go by the dipstick I guess. I don't remember reading anything about the levels being off on them like the FL.
 
The VD oil level should be checked within a minute of shutdown with hot/warm oil.
As for cold check....verify that level is correct with the hot check and in the morning check when oil is cold and drained down. File a mark on the dipstick at that level and you have your cold check point.


Ian
 
He might have been talking about the Lehman dipsticks. Both my SP90's have their dipsticks mounted toward the centerline of the boat but the position of the tube on the block is offset from each other. The angle of the engine installation makes the oil level on each stick different with the same amount of oil.
 
The discussion is about Velvet Drive transmissions and it was to that that I was referring. This is the trouble with abbreviations. VD = Velvet Drive


Ian
 
The VD oil level should be checked within a minute of shutdown with hot/warm oil.
As for cold check....verify that level is correct with the hot check and in the morning check when oil is cold and drained down. File a mark on the dipstick at that level and you have your cold check point.


Ian

Yes, exactly. Once you know and mark the correct cold level you're all set.

Ken
 
The VD oil level should be checked within a minute of shutdown with hot/warm oil.
As for cold check....verify that level is correct with the hot check and in the morning check when oil is cold and drained down. File a mark on the dipstick at that level and you have your cold check point.


Ian

This is a Very good idea. Sounds like Jim Aspel himself telling me when I picked up my newly rebuilt BW from Federal Marine in Chicago. Some engines have a large volume of oil in the cooler than drains back to the tranny when shut down. The transmission will look full with the stick after filling but once running it fills the cooler and lines, and can be starving for oil. Check the level several times immediately after shutdown until it reads full. Some cooler setups can hold a lot of oil. My Perkins cooler holds a lot. when installed mine read full but still took two more quarts after filling the cooler and warming up. It could have been a disaster.

Craig
 
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