Transom Clamp Bolts REALLY Frozen

[lindy46]

Well, here’s a new one for me. I picked up a 1955 Ducktwin and the transom clamp bolts are frozen. I’ve soaked in PB Blaster and even took the handle off to get to the square end beneath. I tried a wrench on the end, and she won’t budge. Anyone have this problem before? ANy ideas? I don’t want to break the bolt or the casting.

[bobw]

If you haven’t tried heating it yet, go ahead and heat up the clamp bracket area around the clamp bolt and apply the PB Blaster. Keep applying heat and penetrant and see if you can loosen the bolts. My ’72 Evinrude had been a salt water motor and the clamp bolts were frozen solid. I ended up drilling 2 small holes through the brackets (one hole on each side of the bracket) to access the inner thread area of the bolts which allowed the PB Blaster to work its way deeper into the entire thread area after I applied the heat. Took a lot of time and patience but I got them out. I plugged the drill access holes with a dab of JB Weld.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[dave-bernard]

the worst case cut the threads flush drill out with larger and larger bits till you are almost hitting the threads. then you can use a tap. and put new or user thumb screws in.

[crosbyman]

heat… then a freeze shock may help….

use a keyboard “duster” air can held upside down and spray 10 seconds $4 at the Dollar store

Joining AOMCI has priviledges 🙂

[garry-in-michigan]

I like that small hole idea – I may fill the hole with a tiny grease. fitting.   I use a Dremel wire brush to clean the rust off the threads that I can reach. (There flexible shaft lets you get in tight places better and, as a bonus, the motor runs at a lower tempriture.) What has given me problems is the screw driver handle on the 3.3 HP Evinrude Sportwin with the fuel gage, and the 7.5 HP neutral clutch Fleetwin. . .

• This reply was modified 5 years, 2 months ago by garry-in-michigan.
• This reply was modified 5 years, 2 months ago by garry-in-michigan.

[frankr]

Being in a salt water area, I’ve seen literally thousands of those screws frozen. Heat doesn’t do a whole lot of good because both the screw and bracket are aluminum and expand at the same rate. Go ahead and try the conservative methods, but don’t be surprised if you wind up drilling them out. Fortunately, they are aluminum and easy to drill. I deliberately drill them off-center, using larger and larger drills till it reaches the threads on one side. Then you wind up with a C-shaped remainder that can be turned out. It is a learned skill. Goof luck.

[billw]

Sometimes, if you heat and cool, heat and cool a few times it can be enough to get things moving a bit. If it does start to tun slightly, just gently work it back and forth, in bigger and bigger arcs. Do not heat it burning hot and then try to turn it, or the threads might gall. Then you will definitely be drilling it out. On aluminum, I like CRC 6-56 for a penetrant. Drilling may be required and is probably the fastest way, anyway; however, if you’re not working against a clock, heat might be worth the try. The good news is, if drilling happens, at least the tap to clean out the threads is found in most standard tap and die sets. If you had an 18 or a 40, you’d be hunting down a larger tap.

Long live American manufacturing!

[lindy46]

Thanks for all the suggestions. The darndest part is I see no corrosion on the exposed threads nor on the casting. I’ll go ahead and drill a small hole in the middle of the casting and spray PB Blaster in there and see what happens. I’m in TN so no salt water, but who knows where the motor has been in its’ 64 years. I do notice rust on some of the other bolts where there shouldn’t be rust – like the bolts on the mag plate. The condenser bolts were really rusted on and so were the bolts holding the spark plug wire clamps. I went ahead and replaced the whole armature plate. Surprisingly, the coils are very new Prufrex coils, so someone replaced them recently, but the points were original. Maybe this motor took a bath at one point in time. The pistons and cylinder walls are clean as a whistle, and compression is good, so we’ll see what happens.

[mas]

I’ve got a Mark 25 that had a frozen clamp too…I spent over a month of a daily propane heat and PB blaster treatment. When I felt it budge just a tad, it was the most satisfying accomplishment. Few things have I spent so much time and effort…but worth it’s weight in gold.

Keep at it,

Mas

[PugetSoundBoater]

I have thought the same as bobw ,drilling a hole through the side of the swivel bracket ,so i can get some lubricant way down in the middle of those inasscessable inner threads . I use a 50/50 blend of power steering fluid and acetone instead of PB Blaster etc. It works real well in my experiences, along with several many heating and cool cycles with a propane torch. I am not saying the other aerosol lubricants are not any good, just prefer mine.
bobw’s comment about once the screw starts to move, moving it back and forth in bigger arc is a very good method. Even though it has begun to move ,i still apply more lubricant and heat, taking my time. BE PATIENT, don’t rush it or you very well may break the bolt off. mas spent a month working to free his clamp, can’t say i have spent that many days on it! It’s not like we have to drive it to work tommorow.
frankr’s comment on the transom bracket and screw both being aluminum and expanding and contracting at the same rate is good to keep in mind,
Many different approaches to this issue.

All of these responses have merit. Keep them all in mind and take your time.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

• This reply was modified 5 years, 2 months ago by PugetSoundBoater.

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