TLDI 40 prop tightening

spoolin01

Seaman
Joined
Jul 30, 2002
Messages
63
A couple of years ago, I got a used inflatable with a 2003 TLDI 40. I used it a couple of times before buying it, and thought I heard occassional clunking in the gearcase when shifting, as if it took a brief second for things to settle in. It was fairly sporadic so I didn't know what to make of it. I took it to a Nissan (not TLDI) service facility at the time I was having some transom work done and asked them to check the motor out overall, mentioning the gearcase noise. At around that time, I swapped the existing Nissan (I assume) prop for a smaller Michigan Wheel. I don't recall if I made the swap before or after the check-out. The guy there said the motor was fine, though I don't recall what if anything he said about what he'd done. I used the motor another couple of times, not noticing any more noise and attributing my prior concern to new toy jitters, then noticed recently that the Michigan prop had about 2mm fore-and-aft play since the washer under the castle nut was bearing on the spline shoulder, not the prop itself. In the process of shimming with another washer, I discovered that the 1/2 turn or so free-wheeling you can get by spinning the prop with the motor in neutral disappears when you torque the prop to 25 ft-lbs, in fact if you torque it even with your fingers, it won't free wheel once your hand leaves the prop. I got out the original prop and spacer that went under the outer washer and installed them, and found the same thing. When I run the motor in gear with the prop nut torqued at 25 ft lbs, it makes continual noises like you're slipping a transmission into gear slowly - a dull but solid tick, tick, tick. When I torque it less, the noises are less. I found a second thin washer for the Michigan prop such that the slop is gone but the ticking noise is barely perceptible, and ran the boat 30 miles or so over the Labor Day weekend. By the way, the spacer behind the prop is in place, with the smaller diameter side facing inward toward the gearcase. In that position, it's just beyond the splines. That appears to be correct by the exploded drawings I've seen and by the way the original prop fits with it. Also, the noise it makes now with the prop tightened is not the same as I thought I heard when I first got the motor, that I can recall. This one is continuous.

What could be going on here? Isn't the prop nut supposed to bear on the prop itself? Shouldn't the prop free wheel a bit in neutral? There's a TLDI service shop across the bay that I'm going to take the boat into, but I was hoping for a little understanding before going in.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,570
Re: TLDI 40 prop tightening

The prop should be sandwiched between the thrust washer (bronze bearing washer) at the LU side, and the stainless flat washer will go under the castellated nut, which in turn is torqued to zero foot-pounds (no play), and retained by the cotter pin.

Typically, (depends on the prop), the compression is against the splined sleeve of the prop. That allows the rubber hub to shear if needed (if striking an underwater obstruction).

The forward prop thrust does not bear against the gear case, but rather against the prop shaft itself.
 

spoolin01

Seaman
Joined
Jul 30, 2002
Messages
63
Re: TLDI 40 prop tightening

It turns out the wrong forward thrust washer was installed by someone earlier and it was bearing on the case or seal face, not the spline shoulder. I bought a Michigan Wheel XHS hub kit (116) and used the thrust washer (still only half the price of the Nissan hardware kit) and the prop can be torqued and still spin freely in neutral.
 
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