Lehman Transmissions

HiDHo · Nov 9, 2018

Looking at a 1987 trawler with these transmissions. engine hours less than 3000, good mainentance records, but have heard from other owners they will have to be replaced usually with twin disc transmissions. Any reality to this information, comments would enter into our decision making.
Thanks
Bill

Ski in NC · Nov 9, 2018

That's a Borg-Warner Velvet Drive transmission. No need to replace, they are good machines and repair parts (at least most) are available. Many many of those boxes out there running every day.

Larry M · Nov 9, 2018

That looks like the back end of a FL SP135 with a BorgWarner, Velvet Deive running gear. We rebuilt ours at 8400 hours only because we had it out of the boat for the fuel tank replacement. They’re easily rebuildable. We had another one in our sailboat that went over 5000 hours when we sold it.

HiDHo · Nov 9, 2018

Thanks Ski and Larry, I didn’t recognize the transmission as a Velvet Drive. Our Monk 36 had one and it was still going strong after we sold, we understand it’s on a third loop now.

psneeld · Nov 9, 2018

I would love to know who starts these absolutely idiotic boating rumors....

If BW transmissions can survive over a decade in an assistance towboat, they should last a century in my trawler.....seals willing...

kchace · Nov 9, 2018

I can tell you for certain that the transmission in the picture is a BW "CR2" transmission. (the aft section is distinctive and I have 2 of my own) This is a "drop center" transmission with a reduction gear in the aft section. Also, they can be had in reverse rotation configurations - all done within the transmission. These are very commonly used in trawlers with Lehmans. Typically in this use they go about 5000hrs and then need a rebuild at which point they can go another 5000. While many of the "CR2 specific" parts are no longer manufactured, there were so many made that most of the rebuilders of BW transmissions have no trouble with rebuilding them using good used parts they either hoard or can easily source from other rebuilders.

Some good info here:

TAD for Velvet Drive CR2 Marine Transmissions, Velvet Drive Transmissions, Velvet Drive Marine Transmissions

Ken

SoWhat · Nov 9, 2018

They are Borg Warner Velvet Drive CR2's. Basically a 71C with a special reduction gear. Common rebuild parts are readily available such as clutch plates, bearings, seals, etc. Gears are available but very pricey. Typical rebuild would run about $750 sans shipping.

Critical to maintain heat exchangers and oil coolers. If you fail to change zinc in heat exchanger, the trans oil cooler will fail allowing raw water to mix with trans oil.

They are seriously over designed and should last a couple of days beyond forever if you keep the oil and zincs changed.

psneeld · Nov 9, 2018

Could be wrong, but I dont believe a zinc in the heat exchanger will protect an oil cooler.

Some oil coolers will have their own zincs, other people just use cupronickel ones that last longer because of their metallurgy.

Some exchange the drain plug for a zinc.

They also last forever if you dont change the oil regularly. At 5 years the oil still looks new but probably is as far as I would go...and have with no ill effects and around 400 to 500 hours per year on them.

SoWhat · Nov 9, 2018

My lehman's have 2 oil coolers and 1 heat exchanger each. They are clamped to the block via metal straps so are electrically bonded. They are level and can't completely drain so electrolyte is always present. Therefore galvanic corrosion is a risk in all 3. I suspect the tubes in the oil cooler have thinner walls so would go first. A zinc in the heat exchanger provides adequate protection.

Cupronickel is higher on the index so should provide slightly better protection.

jleonard · Nov 10, 2018

They are good gears, but longevity varies.
For example, I bought my boat with about 3400 hours. After the first season, I decided to rebuild the tranny. It shifted and sounded fine, but I am a little anal sometimes.
The clutch surfaces were disintegrating. The reverse cylinder had some rust on the top portion which eventually would have broken (happened to a friend of mine).

So I decided to rebuild it myself. Easy work, had to but a manual, some snap ring pliers, borrow a large socket, not bad.
I decided to replace the two bearings, they inspected ok but since I had it apart why not. (the bearings were the expensive parts).
I even paid to have it bench tested before I reinstalled it.
All in all it cost me about $500. After 11 seasons and about 1400 hours still holding up.

angus99 · Nov 10, 2018

When Velvet Drives do fail, why do some folks opt to replace them with Twin Discs? Cost? Parts availability?

This is anecdotal but I was told the Velvet Drives tend to fail on the starboard side of Defevers (more so than the port trannies in twin configurations). When they do, owners often go back with TDs. When this happens the engine has to be lifted with spacers and a longer shaft (or jackshaft) installed to make up the difference for the shorter gearbox.

Any truth to any of this? If so, I can’t imagine why it would apply mostly to Defevers.

kchace · Nov 10, 2018

angus99 said:
When Velvet Drives do fail, why do some folks opt to replace them with Twin Discs? Cost? Parts availability?

This is anecdotal but I was told the Velvet Drives tend to fail on the starboard side of Defevers (more so than the port trannies in twin configurations). When they do, owners often go back with TDs. When this happens the engine has to be lifted with spacers and a longer shaft (or jackshaft) installed to make up the difference for the shorter gearbox.

Any truth to any of this? If so, I can’t imagine why it would apply mostly to Defevers.

Yes, there is a reason for this, but it's definitely not specific to Defevers. The stb side is the reverse rotation side which has an extra set of gears within the transmission to provide the reverse rotation. All else being equal that side typically needs service first. As far as needing to swap out for a Twin Disk or other, there is no need because the transmissions can easily be rebuilt or a good used one sourced. It's not like they are unreliable or hard to find.

Ken

timb · Nov 10, 2018

I looked at a boat with one twin disk and one bw .the owner said the bw failed a 2000 hours because the trans was not designed to be ran in reverse for long periods and the manufacture did install it that way to achieve reverse rotation . no idea of the model #(mid 70's).
I hope there is no problem with the one in the picture . it looks just like mine.

kchace · Nov 10, 2018

timb said:
I looked at a boat with one twin disk and one bw .the owner said the bw failed a 2000 hours because the trans was not designed to be ran in reverse for long periods and the manufacture did install it that way to achieve reverse rotation . no idea of the model #(mid 70's).
I hope there is no problem with the one in the picture . it looks just like mine.

That is correct. There is a model made for reverse rotation. Running a normal rotation in reverse to get reverse rotation is wrong and it wouldn't last, but it is not meant nor sold To be used that way. Sounds like gross misuse or misinformed fear mongering to me.

Ken

SoWhat · Nov 10, 2018

timb said:
I looked at a boat with one twin disk and one bw .the owner said the bw failed a 2000 hours because the trans was not designed to be ran in reverse for long periods and the manufacture did install it that way to achieve reverse rotation

The std BW transmission has 2 friction disks for reverse and 7 for forward gear. Running in reverse with 2 disks is going to result in a very short life span.

BW made a model (CR2) specifically for twin engine installations that rotated in the same direction. The starboard transmission has an extra gear that reverses the direction of the output shaft.

The starboard transmission may have had a higher repair rate but I believe it was because the nut on the 1st shaft had a tendency to back off. The problem is solved by using a castellated nut (I think)

angus99 · Nov 11, 2018

kchace said:
Yes, there is a reason for this, but it's definitely not specific to Defevers. The stb side is the reverse rotation side which has an extra set of gears within the transmission to provide the reverse rotation. All else being equal that side typically needs service first. As far as needing to swap out for a Twin Disk or other, there is no need because the transmissions can easily be rebuilt or a good used one sourced. It's not like they are unreliable or hard to find.

Ken

Thanks, Ken. Nice to know that starboard failures aren’t an urban (marine) myth. The Twin Disc that a PO installed seems like a nice box, except for two things: it doesn’t have a neutral lock out (or it was never hooked up) and whoever installed the TD only used 2 of the 7 bolts required to connect it to the bell-housing adapter plate! :banghead:

I still find it hard to believe it ran for perhaps 20 years that way.

psneeld · Nov 11, 2018

Velvet Drive Tips

Some info about the reversing issue of BW trannies...

Albin · Nov 16, 2018

Kchase (and others) are correct - yours is a BW 10-13 series CR2 (counter rotating) transmission and I'm certain of this because I have the same one. However, I have less confidence in the reliability of this unit than most other people seem to have. The late Bob Smith, founder of American Diesel Corporation, said this particular BW is one of the worst transmissions ever made. According to Mr. Smith. it has a well know design flaw that can cause premature catastrophic failure and you would be lucky to get 2500 hrs out of it. You can contact his son Brian at AD and I'm certain he will give you a similar story. I personally have never had any problems with mine in the 13 years that I have owned my boat so I am definitely not speaking from personal experience. I have an article which details this design flaw so if anybody wants it message me directly and I'll email it to you.

Most parts are available for this transmission and I have collected most of them over the years in case a serious failure does occur but in the mean time, I'm keeping my fingers crossed.

Good luck with yours,
Jeff

Albin · Nov 16, 2018

jleonard said:
They are good gears, but longevity varies.
For example, I bought my boat with about 3400 hours. After the first season, I decided to rebuild the tranny. It shifted and sounded fine, but I am a little anal sometimes.
The clutch surfaces were disintegrating. The reverse cylinder had some rust on the top portion which eventually would have broken (happened to a friend of mine).

So I decided to rebuild it myself. Easy work, had to but a manual, some snap ring pliers, borrow a large socket, not bad.
I decided to replace the two bearings, they inspected ok but since I had it apart why not. (the bearings were the expensive parts).
I even paid to have it bench tested before I reinstalled it.
All in all it cost me about $500. After 11 seasons and about 1400 hours still holding up.

Mr. Leonard,

We had some correspondence a number of years ago, I think on the passage maker forum. It's great to see you are still out there cruising your Albin as I am. Do you have this exact transmission? I would love to hear more about your rebuild. Message me directly and I'll give you my email address so we can correspond that way if you don't mind.

Cheers, Jeff
Bedford, Nova Scotia

Brooksie · Nov 16, 2018

The Velvet Drive in my trawler has been in service since 1962, never been out that I know of. The one in my lobsterboat has been out 3 times since 1971, each time for bad damper plate (not part of transmission) Had it "rebuilt" once just b/c it was out already, needed only seals gaskets and plates.
You won't hear those kinds of reports, even about TwinDisc and ZF or even the new BW 5000 series.

jleonard · Nov 16, 2018

Albin said:
Mr. Leonard,

We had some correspondence a number of years ago, I think on the passage maker forum. It's great to see you are still out there cruising your Albin as I am. Do you have this exact transmission? I would love to hear more about your rebuild. Message me directly and I'll give you my email address so we can correspond that way if you don't mind.

Cheers, Jeff
Bedford, Nova Scotia

I will pm you Monday when I get back home on a real computer. My phone won't let me pm you.

kchace · Nov 16, 2018

Albin said:
Kchase (and others) are correct - yours is a BW 10-13 series CR2 (counter rotating) transmission and I'm certain of this because I have the same one. However, I have less confidence in the reliability of this unit than most other people seem to have. The late Bob Smith, founder of American Diesel Corporation, said this particular BW is one of the worst transmissions ever made. According to Mr. Smith. it has a well know design flaw that can cause premature catastrophic failure and you would be lucky to get 2500 hrs out of it. You can contact his son Brian at AD and I'm certain he will give you a similar story. I personally have never had any problems with mine in the 13 years that I have owned my boat so I am definitely not speaking from personal experience. I have an article which details this design flaw so if anybody wants it message me directly and I'll email it to you.

Most parts are available for this transmission and I have collected most of them over the years in case a serious failure does occur but in the mean time, I'm keeping my fingers crossed.

Good luck with yours,
Jeff

A CR2 can be counter rotating or not. Also, they came in 2 models, a 10-13 which was based off the 71 and the 10-14 which was based off the 72. Other than a 3/4" length difference in the front section between the 10-13 and 10-14 it's not possible to tell which one you have or whether it's counter rotating or not without getting the model info off the brass data tag.

As far as the design flaw goes, yup, they do have one, but even then, most of them go 4000 to 5000 hrs between overhauls and some go much much longer. Don't know how many other transmissions go that long.

Ken

diver dave · Nov 16, 2018

AFAIK, the 1.88 and the 1.91 ratios are the only ones in the series designed to have input and output shafts spinning different directions in FORWARD. Not at all related to the CR versions, which simply reverse the oil pump on the front to accommodate a reverse spinning engine.

kchace · Nov 16, 2018

diver dave said:
AFAIK, the 1.88 and the 1.91 ratios are the only ones in the series designed to have input and output shafts spinning different directions in FORWARD. Not at all related to the CR versions, which simply reverse the oil pump on the front to accommodate a reverse spinning engine.

Right. With the CR2 versions the counter-rotation is done by gears just before the output shaft. Also, the CR2's are available in a complete range of ratios both standard and counter.

Ken

FF · Nov 17, 2018

"3 times since 1971, each time for bad damper plate"

Damper plates can be had in a number of robustness levels.

Sometimes stepping up a level or two is worth the extra bucks, and time to locate it..

Eddieandgail · Nov 25, 2018

I have struggled with high Iron content on my rebuilt velvet drive that has total of 2600 hours due to failed oil cooler 2 years ago. It is the port side 10-13 or 10-14 model. I seem to be headed into the stratosphere instead of improving. At 100 hours after rebuild my analysis showed 810 for Iron. At 38 hours on new oil this year in July It showed 800 and with 85 hours now showing 1070. Report states-

Dark film of fine ferrous wear debris. Check alignment and backlash.

No noises, good pressure, no vibration. This tranny is model that does not require removal of rear motor mounts. Alignment sounds like an external issue but where is backlash adjusted? Don't see how I could have installed incorrectly. Splines on the tranny had to line up with splines on new damper plate or it wouldn't have bolted up properly. Any suggestions or premonitions of impending doom will be entertained.
Eddie and Gail
1987 Sea Ranger 47’ RPH
Lehman SP135

jleonard · Nov 25, 2018

Look up Atlantis Marine Gear on the internet and give them a call to discuss.
They were more than helpful for me.

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