Hi Yachtservice,
I'm west of you in Ashland Wi. Will be heading your way in the next few years and may just hang out for a while. I'm in contact with many 39 owners. Here is a note from an owner who has owned his 39 since it left the mold. He is in the same business as you (fixing boats) Here is his note concerning the strut. Not exactly on target but some usefull info for you. I can get you in contact with him if you are interested. He does not hang out in these forums.
This is unedited
I think I mentioned early last fall to one or both that I had a leaking strutt . Thought I would pass on the Low Down . The factory had bonded the strutt , a good thing , they drilled a 1/4 hole throught FRP knob and the strutt and afixed two (2) bonding wires. One either side with a S.S. 1/4 in bolt . AND there inlies the problem .Oxygen starvation , the bolt separted inside the FRP and the strutt . And then the water seeped up the strutt and out through the bolt , Now that it was not tight . SOOOO if you start to see a liitle water under the engine pan for no apparent reason look under the fwrd part of the hot water heater (Mirror ) and you just might see the seeping drip. The fix is a pain but easy . Pull the heater , make a cut in the heater floor . Pull both bolt ends . Redrill with 1/4 in bit , TAPP completly through with 5/16 tap and pick up a 3 " bronze machine bolt and you get the rest of the picture .NEXT : drill a hole in the TOP of the FRP strutt and tap w/ a 1/8 " pipe , then get a small funnell and poor water in the funnel to wash any salts that may have come up the inside of the FRP and bronze. THEN a dash of Acetone to complete the flush . Now go to the local auto parts store and pick up an inexpensive grease gun (will be sacrificial) and an 1/8'' grease fitting . Back to WEST one or two units of WEST , pump it into the strutt till it comes out of the hull and strutt joint . Got all that ??? . While you are in there it will be a Good time have a good look around . Now I will tell you that you will see the fuel tank platform looking a bit Knarghley . Not much me thinks we can do to help . I am going paint what I can with WEST . . The heater will come out the port cock pit locker door or the if you remove the propane locker it will come out that way too . Might have to loosen the steering cables . But again a good time to poke around a see what condition your condition is in . "Found my mind in the bottom a bag as i was ................" remember that song ?
Ok there ya go , been a crazy winter here .We saw 5 deg. one morning , maybe , all together a foot of snow .warm today . Still busy fixing boats . I looked afer the top of the engine the winter . new glow plugs , serviced the injectors not bad but not good either .Was getting hard to start if it sat for week . adjustd the vlaves , torqued the head . Good for another 4000 hrs .