Velvet Drive 73C Series
By Chris, Hale Marine · 40+ years rebuilding Velvet Drive and ZF transmissionsWhat a 73C is
The 73C is the heavy-duty sibling of the 72C, in part numbers starting 10-06 (10-06-000-004 through -011, listed under AS numbers AS1, AS2, AS5 and AS7-73C, plus a counter-rotating CR version). It comes in four ratios: 1.00:1, 1.50:1, a counter-rotating 2.00:1, and 3.00:1.
How to spot one
As Chris puts it, "most of you probably never heard of a 73." Check the tag for the 10-06 prefix. The other tell is size: a 73C's case runs bigger than a 72C's on the dimension Velvet Drive's chart calls "A," 5.94 in versus 5.63, and its coupling is 5.75 in versus the 72C's 5.00.
Specs
| Spec | 73C | 72C |
|---|---|---|
| Prefix | 10-06 | 10-18 |
| Ratios | 1.00, 1.50, 2.00 (CR), 3.00 | 1:1 up to 2.91:1 |
| Max input, 1982 manual (gas / diesel) | 560 hp / 400 hp | 380 hp / 185-210 hp |
| Dry weight (direct / reduction) | 135 lb / 185 lb | 109 lb / 153-154 lb |
| Case dimension "A" | 5.94 in | 5.63 in |
| Coupling | 5.75 in | 5.00 in |
The 73C figures and the 72C horsepower come from Velvet Drive's 1982 installation manual; the 72C weights are from the later 71/72 spec sheet. The 1988 service manual rates the 72C higher (475 hp gas, 274 hp diesel), so always go by the document that matches your unit's era. A 1987 73C service manual exists, but we haven't reviewed it.
Parts and service
We don't carry a standard parts or rebuild listing for the 73C the way we do for the 71C and 72C. If you've got one and need parts or service, call us: (804) 333-3677, Monday through Friday 9 to 3 Eastern, or email sales@halemarine.com, and we'll go from there.
Related reading
Common questions
What's the difference between a 72C and a 73C?
The 73C is Velvet Drive's heavier-duty version of the 72C, built on a bigger case (about 5.94 in versus 5.63 on Velvet Drive's own dimension chart) with a bigger coupling. Velvet Drive's 1982 installation manual rates it at 560 hp gas and 400 hp diesel, versus 380 hp gas and 185 to 210 hp diesel for the 72C in that same manual (the 1988 service manual rates the 72C at 475 and 274).
What part numbers does a 73C use?
Prefix 10-06, listed under AS1, AS2, AS5 and AS7-73C (plus a counter-rotating CR version), in 1.00:1, 1.50:1, 2.00:1 (counter-rotating) and 3.00:1 ratios.
Does Hale Marine work on 73Cs?
Call us. We don't carry a standard parts or rebuild listing for the 73C the way we do for the 71C and 72C, but call (804) 333-3677 or email sales@halemarine.com and we'll go from there.
Sources
Public documents we used for this page. Links open other websites in a new tab.
- Warner Gear, Identification of older Velvet Drive models 70C/71C/72C/73C (opens in a new tab) PDF, dintra.com
- Velvet Drive 71/72 spec sheet (opens in a new tab) PDF, velvetdrive.com