# removing rusty coupler set screws



## victoria28 (May 4, 2008)

Hi, I have a '92 Catalina 28 - Universal M3-20 engine with Hurth HBW 50-2R transmission and what appears to be the original coupler. I need to remove this coupler and have purchased a new one from Catalina. The problem is getting the heavily rusted set screws to back out. I have carefully soaked all the bolts with a petroleum based penetrating oil. I have had success with loosening the 4 bolts that connect to the transmission, but the set screws are giving me a real fight!
After much scraping & brushing to remove as much of the rust as I have been able to so far it seems like the square heads are now a slightly smaller width than original. As you can see in the attached photo it looks like I'm going to destroy the head and/or break off the screw If I can't find a way to loosen them up.
So please any ideas - helpful hints?
Thanks, Bill


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## scottyt (Jul 19, 2008)

pb blaster and heat. spray them down ( well use a small brush as pb will eat rubber ) and use a propane torch to heat the coupler up some, you dont need red hot just real warm. do this over several days, then try again. also tapping with a small hammer can also help get them loose, heck even trying to tighten them a little can help break them loose

if this does not work split the old one off. ie cut it with cutting wheels in a dremel or if you have the room a grinder. just cut until you are almost thru but not in to the shaft, then use a cold chisel to split it.


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## downeast450 (Jan 16, 2008)

scottyt said:


> pb blaster and heat. spray them down ( well use a small brush as pb will eat rubber ) and use a propane torch to heat the coupler up some, you dont need red hot just real warm. do this over several days, then try again. also tapping with a small hammer can also help get them loose, heck even trying to tighten them a little can help break them loose
> 
> if this does not work split the old one off. ie cut it with cutting wheels in a dremel or if you have the room a grinder. just cut until you are almost thru but not in to the shaft, then use a cold chisel to split it.


Amen!

PB, heat/tapping and patience will loosen almost anything.

Down


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## WanderingStar (Nov 12, 2008)

Also use a socket wrench, it will fit more surface. With worn down nuts, I sometimes manage with a slightly smaller socket.


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## TQA (Apr 4, 2009)

As a last resort make up some shields from sheet steel, old car bonnets are a good source, visit a junkyard and get the gas axe guy to come over with his kit and cut the sucker off. Some one who uses this kind of cutting equipement every day should cut it off with no damage to the shaft or other flange.

Mind you keep some fire supression gear to hand.


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## BarryL (Aug 21, 2003)

*How much time or money do you have?*

Hey,

You can try the heat / soak / try / repeat method. Or you can give up and take out a saw. What condition is your prop shaft? If you suspect it is worn, then just get a good sawsall and start cutting. Cut the shaft. remove the 4 coupler bolts, and be done with it.

On the other hand, if you are short of funds and are fairly certain that the prop shaft is perfect, you can keep on trying to remove those bolts. Once you round the head your best bet will be a large vice grips and a mallet. Heat and oil will help.

Good luck,
Barry


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## imagine2frolic (Aug 7, 2008)

You can find a can of freezing spray in hardware places. That is one way, and the others are patience, and heat. If you do find someone to bring along a torch. Heating the area where the bolt is stuck is all that needed. I know I can cut away the bad piece from the shafdt, but the falling slag, spray, and excessive heat for a prolonged period of time is guaranteed grief. Fixing your problem has been my job for 33 years............*i2f*


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## tommays (Sep 9, 2008)

I will NOT heat up things in the confines of cram packed motor area If soaking does not work as now you have flammable stuff sprayed on the part your trying to heat up 

Its much better to drill out the screw and drill and split the coupling to remove it as its you should not really reuse it anyway


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## Sabreman (Sep 23, 2006)

Here's another viewpoint.... you never replace the coupling without replacing the shaft along with it. The coupling and shaft MUST be machined together to ensure a snug fit. Otherwise, the vibration will shake everything loose. Thus, you can cut the shaft and unbolt the coupling from the engine in 15 minutes. Even if you get the nuts off, getting the steel coupling off the bronze shaft while still in the boat will be nearly impossible. Trust me, I've tried; those bolts are the least of your worries. 

My recommendation is to replace the shaft and coupling together, the stuffing box (replace with a PSS seal), and cutlass bearing (why not?). I've done the job several times on various boats and it's quick and <$1000 if you do the work. I've posted the procedure several times on Sailnet.


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## victoria28 (May 4, 2008)

thanks for the advice from all of you- I have hauled the boat and separated the the shaft & coupler from the transmission - but the coupler with both set screws removed is still not loosening - tomorrow morning I'll try the trick of putting a socket on the end of the shaft and try to use it to push the shaft out by reclamping the coupler to the transmission plate with longer bolts - wish me luck! a good soaking with blaster may help too!
Cheers from sunny and mild Victoria,
Bill


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## 2Gringos (Jan 4, 2008)

since I got my shop compressor and a bunch of air tools a few months back, I roam around just LOOKING for frozen nuts to use my air impact driver on. That hammering twisting force is awesome for knocking em loose. Of course, I also get the giggles using the air chisel...etc. but hey you are past that point now.

Heat can work wonders, especially when you have two different metals together. they have different expansion coefficients. The one you apply the heat to expands a different amount than the other metal. If you apply heat to the coupling, and then cool the shaft, and whack it to break the bond you might be able to seperate them that way. 

By the way, if you REALLY need to put some cool on it, I have found that C02 fire extinguishers can do a good job.


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## xort (Aug 4, 2006)

I JUST finished this project with a coupler that has been on the shaft for 27 years. It would not come off. the flange was heated cherry red and still would not budge. Since you already have a new flange coupler, cutting this one is a no brainer. What worked well for me was drilling a series of 1/8" holes down to the key. Drilling at the key prevented me from hitting the shaft with the drill bit and adding dimples to the shaft. I then used a Dremel cutoff wheel to 'connect the dots', cutting between each drill hole. It went very easy.

You still need to get the set screw loose. PB blaster does work well along with rapping with hammer. Let it soak and reapply. If it won't come out, cut if off flush and then drill the rest out.

As for replacing the shaft, mine was in excellent condition after 27 years. I sent pictures to PYI and they agreed it would be just fine for a PSS.

You will likey find the new flange does not fit easily on the shaft. If your shaft can come out easily, it can be much easier to take the shaft and flange to a machine shop and have them pre-fit them together. It is still a very tight fit.

You are lucky, you have good access to your work. Mine was under a bulkhead and extremely hard to access. Made things even more fun.


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## Izzy1414 (Apr 14, 2007)

xort said:


> You still need to get the set screw loose. PB blaster does work well along with rapping with hammer. Let it soak and reapply. If it won't come out, cut if off flush and then drill the rest out.


Ed,

Good advice for vic. But did you know that not all couplers have set screws?


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## xort (Aug 4, 2006)

Iz
Come to chicago and say that! :hothead


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## T34C (Sep 14, 2006)

x- You couldn't even FIND the set screws, why should he listen to you.


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## Mechsmith (Jun 7, 2009)

If the shaft turns out to have a little wear or corrosion and the new coupler is notsnug on the shaft use some Loctite stud and bearing compound. It will work well to keep things tight.


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## smackdaddy (Aug 13, 2008)

Sabreman said:


> Here's another viewpoint.... you never replace the coupling without replacing the shaft along with it. The coupling and shaft MUST be machined together to ensure a snug fit. Otherwise, the vibration will shake everything loose. Thus, you can cut the shaft and unbolt the coupling from the engine in 15 minutes. Even if you get the nuts off, getting the steel coupling off the bronze shaft while still in the boat will be nearly impossible. Trust me, I've tried; those bolts are the least of your worries.
> 
> My recommendation is to replace the shaft and coupling together, the stuffing box (replace with a PSS seal), and cutlass bearing (why not?). I've done the job several times on various boats and it's quick and <$1000 if you do the work. I've posted the procedure several times on Sailnet.


Sabre - would you point me to one of those posts?


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## Sabreman (Sep 23, 2006)

The following is the procedure that I used to extract the cutlass bearing from our Sabre 28 (2x) and Sabre 38 (1x). On the 38, I opted to replace the coupling, shaft, stuffing box (with a PSS shaft seal), and cutlass bearing. The touchiest part is the cutlass bearing. When I replaced the shaft, I replaced the coupling because a) it impossible to separate the two and b) they must be machined together to prevent vibration. Thus, it was easy to unbolt the coupling from the transmission and then cut the bronze shaft with a hack saw. 

Installing the PPS shaft seal was a snap; the only problem was the limited amount of space between the seal and the new coupling. But it all worked with about 2" to spare. Just read the directions that come with the seal, not complicated at all. 

An added benefit to having the sela is that the prop is now supported in 2 places - at the coupling and at the cutlass bearing. This reduces the effect of engine misalignment. With the traditional coupling-stuffing box-cutlass bearing arrangement, the prop is held in 3 places. We all know that 2 points define a line, but three points better be in the same plane or there has to be a bend somewhere. In the case of a shaft, misalignment results in wear on the cutlass bearing (most common) or in the transmission. Since installing seals on both boats, I've experienced no wear on the cutlass bearing (10 years on the Sabre 28 and 5 years on the 38). So there's my advertisement for a shaft seal 

The entire installation was completed in about 2 hours. This isn't rocket science although a yard may try to convince you otherwise.

Cutlass Bearing Removal/Installation Procedure

EXTRACTION:
1. With a screwdriver or similar, remove as much of the rubber as possible.
2. Take a hacksaw blade and a) grip it with vice grips on one end or b) use one of the commercial holders that allow the blade to project forward unimpeded. I used vice gips because I was too lazy and cheap to buy the holder. Use a rather coarse tpi or you'll be at it all day.
3. Cut/score as much of the inside of the cutlass bearing as possible. It may be difficult to maintain contact along the length of the inside of the bearing, but do the best that you can.
4. Don't worry about cutting through the bearing into the housing. This is slow work. And you'll be stopping often to ask yourself if you'll ever finish (and to cuss me out)
5. When you're almost through the bearing, take a small screwdriver and insert/tap it between the bearing and the housing. This will cause the bearing and housing to separate. Work a larger screwdriver in until there is enough room to grip the bearing with vice grips. (NOTE: I've heard that some people insert a bolt through the strut's set-screw holes and tighten the bolt to deform the old bearing. Good idea, but I haven't tried it.)
6. Don't worry if you score the inside of the housing a little. Don't go ape on it, be careful, but if there is some scoring at the opening where the screwdriver was inserted, it won't affect performance at all. This isn't brain surgery.
7. With the vice grips, twist the cutlass bearing inward to collapse it. With luck and if you cut enough, it will break along the scored line made by the hacksaw blade. Work it until you can pull it out. This may/will require some effort, but it will come loose.

INSTALLATION
1. With fine sandpaper (220 grit) clean the inside of the housing.
2. Remove the new bearing from its packaging and store in the freezer overnight. Transport to the boat in a cooler packed in ice. This will shrink the new bearing enough to insert. Don't skimp on the freeze time.
3. Coat the cleaned housing with dish soap. Be liberal with the soap
4. Insert the new, frozen bearing in the housing that's coated in soap. Be careful and make sure that it's lined up. It will not go in if cocked.

5 You can make a press using a 1/2" or 3/4" threaded rod and fat washers. This is what I use. Practice before actually freezing the bearing and trying the installation.
5a. Put a nut on one end of the rod, slip on a couple of washers and insert from the inside of the boat through the housing, to the outside. 
5b. The rod should be long enough to go through the housing, plus the length of the new bearing, plus about 3". 
5c. Slip the frozen bearing over the rod and and place a 2 or 3 washers over the end of the rod. 
5d. The washer's diameter should be larger than the bearing's diameter. 
5e. Place a nut over the whole contraption and snug up.
5f. With a large wrench tighten the nut, and the cutlass bearing will easily be drawn into the housing.


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## Danny33 (Nov 21, 2007)

I f PB blaster and taping doesent work after acouple days ... Take a torch and heat around the screw / bolt ..let one spot get red and go to work !
Keep a gallon of water for back up if a flare up accurs ..If gas engine run fans before and during operation !


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## scraph (Oct 19, 2009)

victoria28 said:


> thanks for the advice from all of you- I have hauled the boat and separated the the shaft & coupler from the transmission - but the coupler with both set screws removed is still not loosening - tomorrow morning I'll try the trick of putting a socket on the end of the shaft and try to use it to push the shaft out by reclamping the coupler to the transmission plate with longer bolts - wish me luck! a good soaking with blaster may help too!
> Cheers from sunny and mild Victoria,
> Bill


A proper puller tool would be a better approach. This is exactly the situation that a jaw puller was invented for. No sense in placing undue stress on the transmission end flange. It has nothing to do with a siezed coupler/shaft and shouldn't be falsely implicated! In other words, don't use parts as tools.


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## j34035 (Nov 10, 2006)

Its sorta funny, I just pulled my shaft today. I had no trouble getting the set screws out, and used the flange bolts and spacers to push the shaft out of the coupling. Took about 2 hours to do the whole job. Now it is time to start spending money (shaft, coupling, cutlass, packing, etc.....) All in all, not too bad a job.
DD


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## victoria28 (May 4, 2008)

*It took a while but we got it done!*

Well the dastardly deed is done! Last Saturday it took two of us two and a half hours to coax the old coupler off the bronze shaft - but after that the installation of the PSS and the new coupler went just as planned! While I was down there I also put a new drain tap on the wet lift exhaust so I can collect the foul water that discharges if I need to drain it.
I just came back from checking the boat in the water and the bilge is as dry as a bone!
Thanks for all the advice - after several days of patiently and carefully applying generous doses of PB-Blaster the set screws gave in to me - and the rest as they is now history.
Cheers,
Bill


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## Danny33 (Nov 21, 2007)

Just gotta treat them like babys and all works well !
Great job . man !


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