Trojan Boat Forum

putting on the prop you put the key on the shaft, and slide the prop over it i think. So I guess put the key on the shaft and slide into flange?

BobCT--

I'm going after it this afternoon. will let you know if I get the shafts into the flanges.

I got everything clean and polished but neither just "slid" on more than a couple of inches.

With someone blocking the prop with a block of wood, I was able to rotate the shaft, hit it with a hammer and repeat probably 25 times. I used a Sharpie to get started just so I could make sure it was the coupler moving and not the propshaft.

It doesn't take a lot of force but I couldn't see any other way to get it remounted.

Let me know if you come up with the same results or find another way.


Bob

attempted to have someone hit shaft from outside as I held the flange with a piece of wood on the inside, to no avail. I tried that because there seemed to be no room in engine compartment to swing the hammer.

Finally hit it from inside with hammer while someone held the shaft on the outside as you did and got them on. Took more force than I originally thought/planned. Had to use a short handle sledge and just turned and hit, turned and hit, way more than 25 times.

Anyway, got them on (wasn't sure it was gonna work out when I first started.) I didn't join them to the transmission flange yet. Hope I didn't hurt anything from pounding on the shaft flange and the pieces line up ok. But the part I was worried about is now done.

Thanks for all your help!

I have been cringing while reading this thread... since I don't have those couplings felt I had nothing to say.... other than my thoughts that the fit should not be that tight, and concern about mis-alignment.

After some research I found this, which suggest a slip fit is to be expected:

http://www.cruisingworld.com/capable-cr ... 01072.html

Clamp-Type Collars

Stafford Clamp-Type Collars (also known as Split Collars) are designed to retain their position through the clamping power generated by tightening one or more clamp-screws which do not touch the shaft, tube or pipe. The primary benefits of clamp-type collars are that while they are non-marring and easy to adjust, they have a consistently high holding power when used on hard or soft shafts, as well as on thin-walled tubing. They are offered in a variety of materials and styles.

FITS AND TOLERANCES

All Stafford collars and couplings are precision machined to provide consistent fit and function. The statements below indicate the minimum specifications for our parts. Refer to the More Info section of each product category for features that may exceed these specifications.

The Inside Diameters (also ID or bore) of Stafford collars and couplings are sized so as to have a smooth slip-fit over standard shaft material. Depending on shaft size, this is anywhere between .001" to .005" over nominal. A close fit means better seating and better clamping.

The Width of Stafford collars is held between -.005" and +.005" on small parts and -.010" and +.010" on larger parts.

The Length of Stafford couplings is held between -.015" and +.015".

The Outside Diameter (also OD) of Stafford collars and couplings is held between -.015" and +.015". An indicator on the Outside Diameter of a properly mounted collar should show total run-out of not more than .010".

An indicator on the Face of a properly mounted Stafford collar should show total run-out or out-of-flat of not more than .005" for a small part and .015" for a large part.

In a Stafford coupling, Concentricity of bore A to bore B is defined as follows: With one end of the coupling properly mounted on a shaft known to have "0" run-out, an indicator is placed 1" from the opposite face of the coupling on the surface of a properly mounted output shaft. When the first shaft is rotated, the Total Indicated Run-Out (TIR) of the second shaft should be less than .002" for small couplings and .004" for large couplings.

I appreciate this may be after the fact but it may be of help in the future to others or if further adjustment is needed.

I think something would definitley be wrong if the flange "slipped on". Correct tolerances should make it a pretty tight fit. The tight fit occurred at the final stages, past the split in the coupling. I think my problem was more of the inability to get a hammer in there easily. I didn't remove the large floor cover to access the whole engine room. I just went in through the middle engine room acess panel. I think this is what made it more of a hardship. However, i did use some decent force (contrary to what the above post suggests) and I hope it wasn't in error and I screwed something up. It's too late now. I'll let you know if it's messed up when she goes in the water next Sunday.

I followed most of what this guys recommends:
http://www.pbase.com/mainecruising/pss_ ... eal&page=1

I don't see why slipping on the shaft before tightening of the split flange bolts would be wrong?
That is how I would expect it to be designed.... why else have a split flange to make it easier.
You seem to expect a split flange to have the interference fit of a non split flange.... which kind of defeats the purpose of having a split flange in my mind.

It's sounds like yours went on like mine. I accessed the coupler by removing the small hatch under the rear seats and crawling down below. It was a tight fit and didn't allow a lot of room for the hammer.

I might have underestimated the 25 hits, it was probably more but did it the same way (hit, rotate, repeat). I looked at the flange and it's at least an 1/8" thick on the face of it, I can't imagine it got damaged. It moved every time so I conviced myself it was ok. All of the force was being transferred straight back so no stress on the transmission end.

Like you, I'm not convinced the split couplers make removal or install any easier but that's just from what Im reading.

Like you, I'll know once it's in the water. In hindsight, one thing we could have done is something I've done with wheel bearings on cars. Leave one part (the coupler) in the freezer overnight. Sounds crazy but it does work, the contraction from the cold would have helped.

I'll post back once she's in and tested, hopefully this thread will help someone else.


Bob

knowing the force it took to come off (pressing method), and after it was off, everything was still smooth and in good shape....I knew it was going to take some force to get back on. Having done it, doing it again wouldn't be that bad, just didn't know what to expect the first time.

That was the first time removing a flange, so I've never removed one that wasn't a split coupler, so i too, have nothing to compare it to. One thing it sounds like is that a split can be used over again. A regular coupler's tolerances are messed up after removal and it isn't worth atempting to put back on for ferar it will be to loose. the split coupler allows additional tightening around the collar I guess.

The cooling does work we have used this many time in our plant. In this case it would be the Shaft that would need to be packed in dry ice. Or you could put the coupler in an oven and heat it to expand over the shaft. We would do both freeze the shaft and heat the bushing or whatever was to be joined to the shaft.