Couplings Don’t Get Along Anymore

Gang, here is the latest installment of my strut bushing replacement nightmare. I have come VERY far and have overcome many hurdles in along the way. The new bushings are in, the OJ dripless seal is on the shaft, the coupling is back on the single-taper shaft after sitting on the barbie for a while. My one engine mount is now freed up and spinning nicely.

Now, I have the couplings roughly in alignment (I've checked with a stack of feeler gauges around the gap- it's basically even all around). However, amazingly, the halves won't come together anymore. The inner lip of the shaft-side coupling will not go into the corresponding seat in the trans-side, no matter what. I can't find any obvious reason for this- nothing obstructing either side, no gross misalignment that I can spot- they just won't come together. I'm cold (it's 41 in the garage), all of my knuckles are busted, I've put about 20 hours into this project and I'm FURIOUS. What could this interference be?

I just tried pulling it together with the bolts, without over-doing it at all, just getting them snug, and there is absolutely no chance of them going together. The shaft coupling is on the shaft exactly where it was- the shaft end is flush with the inside of the coupling. There is NO obvious interference whatsoever. It's behaving exactly as if the shaft-side diameter of the coupling shoulder/lip has actually increased in diameter. I'm STUMPED.

M3 - I'm sure the experts will chime in soon, but I'm beating themto this punch. If it was me, I would mic (micrometer) the male pilot to see if you have egged it on the barbie. If it is still round, maybe you could try some light sanding with emory cloth on both the ID & OD of the pilots. Don't get carried away though.

I currently have the shaft out of my boat so thanks for alerting me to this problem. I will definitely trial the couplers fitup before heat-shrinking the coupler onto the shaft.

Joel, Put some paint or even some "white-out" on the lip. (Ideally layout blue but the paint or white out will work) Pull it together and then apart to see if the lip is actually interfering. If it does turn out that it is hitting, I wouldn't go after it with abrasive paper but rather a flat single cut (fine) file. Keep the flat of the file on the face of the coupling but when filing the pressure against the lip. It will just keep things square. This will also hit any high spots on the coupling face. You will see any high spots with the filing.

By the way, any burn spots in the carpet? It looks like you didn't have any problems with heating up the coupling and getting it on the shaft!

8122pbrainard wrote: Joel, Put some paint or even some "white-out" on the lip. (Ideally layout blue but the paint or white out will work) Pull it together and then apart to see if the lip is actually interfering. If it does turn out that it is hitting, I wouldn't go after it with abrasive paper but rather a flat single cut (fine) file. Keep the flat of the file on the face of the coupling but when filing the pressure against the lip. It will just keep things square. This will also hit any high spots on the coupling face. You will see any high spots with the filing. By the way, any burn spots in the carpet? It looks like you didn't have any problems with heating up the coupling and getting it on the shaft!

Pete, I love that idea and I'm going to try it right now. I'm also going to hit it with a caliper to see if it is in fact "egged". The shaft key gave me a little trouble when I was getting the 400-degree coupling onto the shaft but other than that it was fine. First time I've used an oven mitt on a boat project!

I love it when a plan (or coupler) comes together.
Pete,you are too quick for me with your responses.I was going to sugggest some dykem to show the high spots but you beat me to it.

                                    Farmer

By the way,what time zone is this forum in anyway ?

Brad,sorry but I don't see it in my profile.What am I missing? Gary

alignment time!!!
aignment probably is the worst thing mechanically that needs to be done on a boat, on Thursday it took the better part of the day to align a Bravo drive on a Formula, but it had to be done, the 2 engines are exactly 5" apart and almost impossible to get to the mount nuts. i will use a 1 1/16 crows foot which will work well. i could of slammed this drive back on with out aligning but...practice what you preach, i aligned it

Is it a good idea to add some sort of grease between the couplings to avoid them getting fixed together???

eric lavine wrote: maybe a touch of Never Sieze, how was your alignment?

Good. The smallest feeler gauge was .002 so I got it that far for sure! Coupling faces were certainly not warped. Can't wait to get this baby in the water.

8122pbrainard wrote: M3Fan wrote: Good. The smallest feeler gauge was .002 so I got it that far for sure! Coupling faces were certainly not warped. Can't wait to get this baby in the water. Joel, I still can't get over all the problems you went through just so you don't have a dripping shaft! Next time will be easy. You always learn on DIY projects.

Pete, the primary goal was replacing the strut bushings with high-performance Vesconite bearings from OJ Props. The dripless seal was just icing on the cake!