Direct replacement for a Paragon SA1D?

[Carl Behrens]

Hi, I’m restoring my 1970 Morgan 40 Cruising Ketch. I plan to have the Perkins 4.108 hauled out and rebuilt. My drive train is a Paragon SA1D gear bolted to the 4.108 on the forward end and a Walters V-Drive on the other end. I’m afraid of the drive because it is old, and I don’t see any replacements available. I’d like to instal a new drive (gear) but am concerned that it would have to be virtually the same size (length at least) or it will change the angle of my propeller shaft. I assume it will have to have the same bolt pattern on the forward end to make up to the existing bell housing. Do any of you know of a marine gear that will bolt right in? I wouldn’t mind replacing the bell housing as well if that’s needed?

[tkeithlu]

Here's a used one for sale.
Paragon / Westerbeke SA1D-521 Marine Transmissions | Model Number: SA1D-521 | Paragon / Westerbeke Rebuilt Transmissions

I think that if I were in your situation I would consider buying a spare and storing it against a failure.

Switching components, and adapting them to be compatible with other components, is always possible and probably one monster headache. The cost of adapting is likely to take your breath away as well. It is possible that you will run into a brick wall on finding a spare, but computer time searching may be better than time spent writing checks to machinists.

You might also consider having the SA1D overhauled while you're doing the engine. Old oil seals, for example, are a common form of failure, and they are relatively cheap to replace. In all likelihood, the gear train itself is just fine.

Good luuck with it.

[Mickeyrouse]

I would also suggest replacing the shifter links inside (there is probably a more technically correct term.) Their failure will prevent shifting into reverse. They tend to wear and break with age and use. Mine did so- after 30 years and 7,000+ hours. Even if a Paragon replacement part is no longer available, most likely the case, these links are only about 3” long originally stamped from about 3/16” flat steel with a couple holes bored. They are irregularly shaped, but with the old ones as patterns any semi-competent machinist could make replacements.

If the old Paragon can be re-built, it is one really robust gear.