CR-2 (Borg-Warner) Series
By Chris, Hale Marine · 40+ years rebuilding Velvet Drive and ZF transmissionsCR-2 stands for counter-rotating: it's Velvet Drive's drop-center transmission, built so a twin-screw boat can run two engines that turn the same way and still get one prop turning each direction. The input shaft sits up high and the output shaft sits lower, about two inches on the units Chris has opened, though the offset depends on the ratio. Part numbers run 1013 (built on 71-series internals) and 1014 (built on 72-series internals).
A distributor parts list gives four ratios: 1.58:1, 2.03:1, 2.47:1 and 2.93:1. Around the shop we usually just call them by round numbers, 2.1:1 and 3:1, so don't be surprised if a tag and a parts list don't match to the decimal.
These transmissions are obsolete. Some of the components, like the clutches, pump, input shaft seal, neutral safety switch, shift lever housing, selector valve and pressure regulator, are different from the standard 71/72 line and don't interchange. Chris's advice is that it's best not to deal with them if you can, but there really isn't a good replacement. The 1013 went out of production in the early 1990s, and for a dead one today, Chris's own cross-reference call is a 1018 (72C) rather than a 1017, because it's the closer replacement.
Common on trawlers
They were mainly used in trawlers with Lehman and Perkins diesels, including a lot of Taiwanese-built trawlers that came over in the 1980s and into the early 1990s.
What we've found in them
- Paper clutches. A 1014-005 that looked pretty much original still had its early-80s paper clutches. Paper doesn't stand up as well as bronze in a boat, so we replaced them with bronze.
- Flat selector valve O-rings. On the old cast-iron transmissions, the selector valve O-rings get flat on one side and the fluid passes by. A good O-ring is nice and round and symmetrical.
- Grease where it doesn't belong. On one 1013, someone had packed grease into the selector valve area, and that was the actual cause of a pressure problem, the second one we'd seen like it in a month. Keep grease away from the selector valve and neutral switch.
- A sticking regulator piston. The pressure regulator piston has to move freely. Grooves, scratches or metal filings in the bore can jam it, and the piston can look fine from the outside while the bore underneath is damaged. It happens on any of these old cast-iron transmissions, a CR-2 included.
- Overheating. On a 1014-007 3:1, the clutch drum was overheated, and the reduction planetary teeth were getting shiny and starting to break apart. A good drum is nice and shiny with no problems inside.
- A worn output coupling. On a 1013, the nut had backed off at some point, and the coupling went up and down and wore a groove.
- No planetary on the shelf. On one 1013, no replacement planetary was available anywhere, from anyone. Chris had his machine shop reshape a standard Velvet Drive part to fit.
On a 1014-005, a new selector-valve spring took our stand reading from about 100 to 110 psi up to 150.
Related problem articles
Sources
Public documents we used for this page. Links open other websites in a new tab.