Maintaining Belt Tension

One day I discovered the romantically named Belt Tension Jack. Suddenly belt tensioning not only lost all its emotional tension, it even acquired a certain elegance.

I don’t know about you, but for the longest time I always had problems getting my diesel’s alternator drive belt tensioned correctly. For starters, the engine is mounted backward, so to check the belt tension I first have to empty the cockpit locker, then climb into it and contort myself until I can get my arms and head under the cockpit sole and in the right position to reach the belt and pulleys. Fortunately, the belt always seems to need adjusting, so it’s never a wasted effort.

Beyond that, what really annoyed me was that after the usual rigmarole of loosening the pivot bolt and the pinch bolt on the adjusting arm, and then levering the pulleys apart with a long screwdriver until the tension felt right, then tightening the bolts again, the belt was always a little looser than I wanted. Inevitably, the screwdriver would slip or I’d misjudge the tension, or both. There was just no getting around the fact that it was one of those jobs you really need three hands for, and the result of having only two was an engine coated in that fine black dust that comes off poorly adjusted drive belts—not to mention frequent trips down to the dungeon to do it all over again.

Then one day I discovered the romantically named Belt Tension Jack. Suddenly belt tensioning not only lost all its emotional tension, it even acquired a certain elegance.

This clever tool has one purpose and one purpose only: to push two pulleys apart, thereby applying tension to the relevant belt. Juggle it between the pulleys you want to separate, and then crank on the hexagonal body with a wrench to extend a threaded rod with a curved horn on its end until the belt is properly tensioned. After that you can nip up the nut on the pivot bolt and tighten the pinch bolt on the adjusting arm at your leisure, humming a merry tune as you go. Brilliant! There’s nothing like using the right tool for the job, especially a tool you had no idea existed.

This is one of those little things that turns an unpleasant chore into a simple and quick maintenance task. You can buy these nifty tools from MSC Direct for around $20.

Belt Love

• A belt that’s too tight can cause wear on pulley bearings, and one that’s too loose can affect alternator output

• As a rule of thumb, if the belt deflects no more than half an inch when firmly poked with a finger, tension is about right

• Belts are not expensive and should be replaced annually along with engine oil and fuel filters. Keep the old one as a spare

• If you’ve installed a new belt, check its adjustment after a few hours of motoring. It will have loosened and may need retensioning

• Clean that nasty black dust off your engine and alternator. It can foul up the alternator’s delicate interior works. A sponge or rag coated in WD40 works well



Boat Review: Dufour 530

Dufour Yachts seems to have shifted its strategy with the introduction of the new 530. Previously, the French builder maintained two lines: Performance and Grand Large, with the latter targeted at the cruising crowd. With the Dufour 530, however, Dufour decided to combine the more


11th Hour Christens Two IMOCAs, Hits a Snag

This week has been a big one for the American-founded, sustainability-centric ocean racing team 11th Hour Racing. In addition to christening their two new boats, the team also took them out for a quick test ride—against some of the most intense IMOCA 60 skippers in the world. more


Clewless in the Pacific

Squalls are well known to sailors who cruise the middle Latitudes. Eventually, you become complacent to their bluster. But squalls vary in magnitude, and while crossing from Tahiti to Oahu, our 47ft Custom Stevens sloop paid the price for carrying too much canvass as we were more


SAIL’s Nigel Calder Talks Electrical Systems at Trawlerfest Baltimore

At the upcoming Trawlerfest Baltimore, set for Sept. 29-Oct. 3, SAIL magazine regular contributor Nigel Calder will give the low down on electrical systems as part of the show’s seminar series.  The talk will be Saturday, October 2 at 9am. Electrical systems are now the number more


Bitter End Yacht Club Announces Reopening

Four years after being decimated by Hurricanes Irma and Maria, the Bitter End Yacht Club is set to reopen for the Winter 2022 season. Hailed as one of the best anchorages in the Caribbean and built by sailors, for sailors, this island outpost in the BVI has been a favorite with more


Cruising: Bluewater Pollywogs

Bluewater sailing is 25 percent actually sailing and 75 percent learning how to live on a boat at sea, in constant motion and with no chance to get off the roller coaster. I cannot over-emphasize how difficult normal daily functions become at sea, even on nice, calm days. more


Refurbishing Shirley Rose: Part 2

If you missed the first installment, click here. Thankfully, the deck and cockpit of my decades-old Santana 27, Shirley Rose, were in pretty good shape. The balsa core, in particular, was for the most part nice and solid. Nonetheless, there was still a fair bit of work to do. more


Orca Encounters on the Rise

This week’s confrontation between a pod of orcas and the Nauticat 44 ketch Tuuletar which left the boat rudderless is just the latest in a string of encounters with orcas off the coast of the Iberian Peninsula. In fact, over 50 of these encounters have been reported, half of more