Borg Warner Velvet Drive Transmissions

Does any one have any history of these, either good or bad.

I have a customer thats been told to avoid them. I have no personal knowledge of anything that suggests that they are trouble.

MT

Well the main issue with them is that the transmission that is reversed on a twin engine boat has been known to self destruct. One of the nuts that hold the reversing gear on is not secured by a locking pin or lock nut and it can back off. I dont know the exact part, but this will give you a general idea. The next problem is finding parts or someone to work on them. Mine are 25 years old and have not given me any trouble, knock on wood!!

I have B/W Velvet Drive CR2 transmissions. Last year we pulled the Starboard and had it re-built for the exact reason that Troy pointed out. Our local Velvet Drive dealer recommended that this be done and at 2,000 hours, he felt that we were living on borrowed time. I pulled and reinstalled myself, so the shop costs were only around $1,500 or so. Also replaced the drive plate while I was at it. I plan on doing the Port next winter.

Velvet Drives work fine when they are mated to an engine that is suited for them, like the Ford Lehman 120. They may not be so reliable when mated to a higher-powered engine. They have been used on a billion boats starting in the 1960s so have a pretty good record of reliability. Like anything else, they have to be operated and maintained correctly to get a long life out of them. Probably the hardest thing on them is impropper shifting technique. There are several versions of the BW transmission--- the drop-center versions seem to be the ones that are the most trouble-prone.

As to parts and maintenance, it may depend on where you are located. Here in the Puget Sound region of the PNW there are a number of marine gear and diesel shops that work on Velvet Drives and so far as I'm aware, parts are not an issue. This may not be the case in other parts of the country.

Depends on the version.

The CR2s do have the problem that Troy mentioned. And as Max wrote, it can be fixed.

The larger 71 and 72 models have good reputations from everything that I've seen and heard - especially if you're not pushing the HP/torque ratings. The engine surveyor who did my boat said that the 72s that I have should be rock solid with routine maintenance.

Can anyone determine how to identify a Drop-Center version? The serial numbers on the units in question are not identifiable

I found this on the web.* http://www.marinegears.com/catalog/cat-idx-bw.html* At the top of the contents box is a Dimensions and Ratings section. There are side-view line drawings of the CR2 drop center, the in-line (71,72), and the Vee-drive Velvet Drives. Note that on the drop-center Velvet drive the rear section of the gearbox extends down a bit below the bottom of the case holding the forward section.* Also the aft portion of the in-line Velvet Drive is enclosed in a smooth case or "bell housing."* From the drawing, the rear housing of the CR-2 drop center has a bunch of ribs cast into it and is not smooth.

-- Edited by Marin at 12:08, 2008-04-29

C. Marin, your link was dead on. It showed me exactly what I needed to know. I appreciate your help on this. It was a Drop Center

If anyone else wishes to see a photo of an actual CR2, drop me an email and I'll send you one. Or could I post it here somewhere?

MT

If I read your query correctly and you're not sure how to attach a photo to a*post, select "Reply," write your post, and then check the little*"Attach Images" box under the text window.* Then scroll down and hit he first*"Browse" button*and find the photo on your computer and select it so its name appears in the window to the left of the "Browse" button.* Then scroll down to the bottom and select "Upload Images."* It will take a few moments to upload the image.* When it's done so, select "Submit Post" and you're done.* There is a file size limitation to photos--- too big and they won't load. I think the limit is 2.5 mb but I could be wrong on that.

If you use the "Quick Reply" box instead of the "Reply" button, select "Advanced Editor."* That will take you to the reply form that lets you attach a photo.

-- Edited by Marin at 19:13, 2008-04-29

Thanks for the help there Marin. I have been outta service for awhile and am just getting back to "normal". Glad the original poster found his solution!!!!

Yep, we bought the Albin 43 with the velvet drives and they purred like kittens from Tampa, through the Keys and back up north.
MT

http://my.boatus.com/forum/forum_posts.asp?TID=62821&PN=2


Found this interestting.* I may try to do my Port side myself this winter.

CR2 Velvets:

Has anyone noticed the starboard (reverse rotation) side running hotter than port? Mine was rebuilt 300 hrs ago at a reputable shop, but it is running 30 degrees hotter than port. Not sure if it always did. We bought the boat 200 hrs ago. Any thoughts??

I have two 72C with 2.57 or 2.91 gears and they are fine.
I had port side leaking oil, so I took it apart. was easy to repair myself.
One of the large O-rings on the inside, I think the one that seals the front oil pump to the gear case, rust had built up on the metal face. Oil was weeping past the rust. I cleaned off the surface smooth with a razor blade. I did put in new seals and clutch friction plates, but the OEM ones were in perfect shape, so I kept all the original parts.
The inline ones in my experience are very nice transmissions. The one disadvantage is they can not spin equally forward or reversed, they have to be setup by rotating the inner pump one way or the other way. Something about one way uses a bushing versus a bearing, so one motor in a twin setup must be counter rotating, which pretty much your out of luck if you want to use a twin diesel with two 72C's.

CR2 info
http://www.tadiesels.com/borg_warner-cr2.html

Although one way to use a diesel and a 72 series and get counter rotation would be to flip the diesel engine around taking power off the nose.

Thanks.

My stbd side CR2 is reversed gears 1.58 to 1. Both engines rotate normally.

schaefferoil said:

CR2 Velvets:

Has anyone noticed the starboard (reverse rotation) side running hotter than port? Mine was rebuilt 300 hrs ago at a reputable shop, but it is running 30 degrees hotter than port. Not sure if it always did. We bought the boat 200 hrs ago. Any thoughts??

Click to expand...

I do not believe one should run hotter than the other and 30 degrees is a pretty big difference. I have CR2's and I check the running temps at least once on any cruise more than about an hour. Both of mine run about 150 deg F and always within a couple of degrees of each other. According to the manual, they should never exceed 190. You could have a partially clogged cooler or perhaps the oil is getting too low. You should also verify that the shift lever on the transmission is shifting to exactly the correct location. Not shifting fully could cause the transmission to slip which would raise the temps. Slipping would also trash the clutches pretty quickly.

Ken

That sounds good. The fluids are on spec, level, and new. I changed in-line filters too. Shift position seems good.
Will look into the cooler.

Thanks!

Max Simmons said:

Found this interestting.* I may try to do my Port side myself this winter.

Click to expand...

The parts will be a little more than the $300 the guy quoted (that was 2008). The oil cooler alone cost me $250.

When we ran fishing boats, I had a guy who ran a small automotive transmission shop who would rebuild them for us. He stocked the rebuild kits and could have them done in a few hours if he wasn't busy. He said they were pretty simple.

Be sure and replace the flexplate, between the flywheel and transmission, at the same time even if it looks fine.

"Has anyone noticed the starboard (reverse rotation) side running hotter than port? Mine was rebuilt 300 hrs ago at a reputable shop, but it is running 30 degrees hotter than port. Not sure if it always did. We bought the boat 200 hrs ago. Any thoughts??"

These Tx have been around for years. IR guns, not so long. maybe your port side is running too cold? What makes you think this might be a problem? I think you have too much information.

Marin said:

Velvet Drives work fine when they are mated to an engine that is suited for them, like the Ford Lehman 120. They may not be so reliable when mated to a higher-powered engine. They have been used on a billion boats starting in the 1960s so have a pretty good record of reliability. Like anything else, they have to be operated and maintained correctly to get a long life out of them. Probably the hardest thing on them is impropper shifting technique. There are several versions of the BW transmission--- the drop-center versions seem to be the ones that are the most trouble-prone.

As to parts and maintenance, it may depend on where you are located. Here in the Puget Sound region of the PNW there are a number of marine gear and diesel shops that work on Velvet Drives and so far as I'm aware, parts are not an issue. This may not be the case in other parts of the country.

Click to expand...

I ran into a transmission guy in Miami who said they were bullet proof.

He told me should I run out of transmission oil, any oil will do in a pinch.

And in an emergency, water will even work for a bit, but not too long.

Yes, I expect they are pretty good, and rebuildable - just difficult to get hard parts for.

Don't like the temp dif on mine.

schaefferoil said:

Yes, I expect they are pretty good, and rebuildable - just difficult to get hard parts for.

Don't like the temp dif on mine.

Click to expand...

My reverse rotation (Stb) CR2 was rebuilt at about 4500hrs. It didn't fail but had gotten noisey. I just had the port one rebuilt at 5000hrs because it was getting worn inside and a bit noisy - though it still worked perfectly. There are a fair number of good rebuilders around the country and they hold on to their parts to do their own rebuilds.

Ken

Rebuilt 71c in 99, ran well til 2015 after many 000 hrs, now on second rebuild. Still make em. My choice anyway great service for me.

Anyone know the socket size for the nut that holds the coupling on to the splined shaft on a CR2? I'm flinging oil from the splines due to a loose nut.


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The joys of a CR2. The one-time use nut is $43.


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Greetings,
Mr. m. I think there may be 2 sizes. A call to American Diesel should confirm or deny.

meridian said:

The joys of a CR2. The one-time use nut is $43.


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Click to expand...

How about some loctite instead?
When I rebuilt my 72C series, I did not get a new nut.
I dont think I did use any loctite, and it has been 15 years since.

Marin said:

. Probably the hardest thing on them is impropper shifting technique.
.

Click to expand...

Hi Marin,

By this do you mean slamming from fwd to reverse or vice versa or slipping the gear - bit like riding the clutch if it was a car?

meridian said:

Anyone know the socket size for the nut that holds the coupling on to the splined shaft on a CR2? I'm flinging oil from the splines due to a loose nut.


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Click to expand...

According to my CR2 service manual there is only one nut, part number 10-00-149-034. I measured mine and it is 1.665" which sounds like 1 11/16.

Ken

If I want to know anything about a Velvet Drive I would give a call to Jim Aspel at Federal Marine Transmissions in Chicago (Countryside IL). Ph: 708.352.2200 He rebuilt a port side tranny for me last fall. I was extremely impressed. I have a somewhat obscure model 1014-001 tranny that apparently some parts are extremely hard to come by. It seems Borg warner dropped this transmission from their line some time in the late 80's and just scrapped the parts. Many parts are common with the mainstream models but some are not. He warned me that the reverse rotation starboard tranny could be a problem and to take good care of it. I was extremely happy with his work. It wasn't cheap, but it might have been a whole lot worse if he had not given me a break on many of the parts. I went away with an absolutely good feeling that the tranny was probably (certainly so) better built than it left the factory. The guy has records by serial number, of a overwhelming number of BW Velvet Drives and can tell you every thing that has passed thru his shop. Including inspection measurements. He repairs transmissions far beyond Chicago and was credibly critical of of other 'experts'. He apparently worked for Borg Warner for a time and was very connected with the factory engineering team. I believe you can trust what he says. Give him a call, Have time to talk, he likes to talk, but listen close, because is the most knowledgeable guy I have ever run into.