Saturday, October 17, 2009

Engine alignment and other reconnecting tasks

I haven't had a lot to report over the past few days as I was away for travel and the work of aligning the engine is tedious. I think I was spared the worst case scenarios associated with engine alignment because now that I am done, I would estimate it took about 6-9 hours of time and a lot less donated skin than I anticpated. Not too bad really.

My transmission flange and prop shaft flange were already within reasonable tolerances when I dropped the diesel back down onto the new mounts. I had eyeballed the new mounts to match the old ones, as you would, and got lucky. However, when you need to get two surfaces within .003", being close is not much reassurance.

I believe my first check of the gap had the difference between the small gap and large gap at around .015". I was also able to eliminate other sorts of problems that Calder et. Al. mention by noting that the gaps did not rotate with the shaft, but stayed in the same place. This eliminates concern about the shaft itself, or the transmission flange itself, being warped.

I had to lift here, and drop there, and lift here and drop there a little bit. Each time I had to rehoist the engine off the mounts as the only access to the lower adjusting nut is when the engine is 12-24" off the mounts. This was actually the hardest part. I didn't want to tighten the nuts clamping the mounts to the stringers until I knew that I had the alignment pretty darn close. When I got that very close, I went ahead and tightened all the mounts to the boat, and then did the remaining adjustment with the mounting height nuts only. More specifically, the mounts themselves determine the left/right orientation of the motor--or movement in that plane. Once that is good, you can tighten them and deal with the up/down movement with the adjusting nuts on the bolts of the mounts.

Anyway, that's all done and now I am putting everything back together. I purchased a new heat exchanger from Lenco as our old one was original and dying. That will be reassuring as I had patched a few places in the old one and always worried it was going to blow at any moment. While doing all this, the other thing I am really excited to fix is the shifting of the transmission.

The shift arm on the transmission is supposed to travel far enough in both directions to fully engage the clutch. If this doesn't happen, and it often doesn't, you will prematurely wear out the clutch in your transmission (read: $1500). I knew my trasmission was slightly out of adjustment because when I shifted into forward, it barely seemed to engage and did not click solidly and reassuringly into forward. Exactly the problem I needed to solve.

Turns out in my removal and lubricating of all the shifting mechanisms that the easiest way to adjust hte lever travel is at the lever itself. It clamps to a round shaft coming out of the transmission and can be clamped in any position. So you can move the shaft to the full engagement place in forward, and then tighten the lever arm to it at the full extent of it's forward travel. So long as you have enough total range of motion in the system, this will ensure that you have solid engagement of the clutch. It feels great, and solid, and I am so happy to know that clutch is fully engaging.

Side note: Anyone who has every taken apart a trasmission of any sort, especially automatic transmissions, will have a profound respect for the importance of clean oil and proper adjustment. The whole damn thing relies on just enough friction, but not TOO much friction.

The mixing elbow, which I replaced with a nice new one a few months ago, is attached to the exhaust manifold with a high temp silicone gasket material. It has worked very well for me and is cheaper and easier to get than the manufacturers gasket. 

So the putting back together is going well and I hope to have the diesel started and be out sailing again maybe by the end of this weekend.


eherlihy said...

thanks for the writeup of this. It is an intimidating job.

What model Westerbeake engine is it?


The Windrope Family said...

The diesel in these boats is a Universal 5432, which predates the Universal M40 but is essentially the same. A 4 cylinder 32hp beast that has been solid.