Frozen Trim Tab Bolt

[bobsquatch]

My 1973 Johnson 115 model 115ESL73 trim tab bolt will not budge. I have applied heat, penetrating oil, ice an impact driver and an air impact wrench to it. The trim tab will rotate through its range tapping it with a small hammer but the bolt does not turn. I rounded off the head but was able to make a good slot with my Dremmel tool but hours of hitting it with an impact driver is wearing it thin. I was also able to put an air impact wrench on it medium lightly to rattle it hard for a descent amount of time but gave up as it was was wearing out the slot. Any thoughts?

 

[boobie]

What kind of heat did you use ??

 

[rolmops]

I would drill it out so the trim tab itself can come off, but make sure to leave enough flesh to be able to put a vice grip on it. Now with the trim tab out of the way brush the bolt with a steel brush so all the build up at the bolt body connection is gone and apply heat (a lot of it) ,now spray penetrating oil a few ties and heat it up again and apply penetrating oil again. Now heat it up again very hot,and set the vise grip on it to see if it will budge.Don't over force it ,just repeat until it moves and it will.

 

[boobie]

Edit. Double post

 

[boobie]

Apply the heat around the bolt, not the bolt itself.

 

[bobsquatch]

What kind of heat did you use ??

Propane torch. One mild tip one hot (for propane anyway) I have been heat cycling and using penetrating oil in turn. Not much progress yet.

 

[bobsquatch]

Apply the heat around the bolt, not the bolt itself.

I have been doing both I started heating the casing above the bolt and putting ice on the bolt head itself heating the metal to expand it and cooling the bolt to retract it to no avail and then I just got stupid and went both ways cooling the casing and heating the bolt just to get is much contraction and expansion as possible in every available opportunity. I think I am far away enough from all seals and rubber to avoid damaging any components

 

[bobsquatch]

I would drill it out so the trim tab itself can come off, but make sure to leave enough flesh to be able to put a vice grip on it. Now with the trim tab out of the way brush the bolt with a steel brush so all the build up at the bolt body connection is gone and apply heat (a lot of it) ,now spray penetrating oil a few ties and heat it up again and apply penetrating oil again. Now heat it up again very hot,and set the vise grip on it to see if it will budge.Don't over force it ,just repeat until it moves and it will.

That was my nuclear option. I figure if I cant get it I could drill out the trim tab in a few places and smash it apart leaving the bolt and whats left of the head to work with.

 

[boobie]

You may want to try some Mapp Gas. It's much hotter.

 

[bobsquatch]

The one good thing I am getting through the heat cycling is a fairly prominent tick from the metals cooling at different rates, a good sign. Its funny the rest of the lower unit bolts I need to remove to service the water pump look pristine. I dont think red Loctite is a factor or the fire would have solved that. It could have been over torqued and that will be my guess if the impeller looks good (recently changed) or it could just be corrosion. We will see eventually... I hope.

 

[bobsquatch]

Well that was frustrating. I got about 1-1/2 turns over 5 hours with two propane torches and a ton of effort. With the exact right heat application I could get the bolt to turn at about 45lbs of force. Unfortunately the boogered up bolt head could only sustain about 50lbs of effort so the margin was way thin. Eventually I wiped out the bolt head and cut up the trim tab with a die grinder. Could have done that hours ago but I knew I could save the trim tab. Doh! Anyway it is out and now I can soak it with penetrating oil and finish finish the job tomorrow. The good news is the impeller was due for service so it was a worth while endeavor but I will speak to that in another post. Thanks for all the help.

 

[gm280]

Well that is good news all the same. You may have buggered up the bolt and trim tab, but those are replaceable... New bolt and tab and you're back in business again... :thumb: Have to always look at the bright side of things!

 

[bobsquatch]

Absolutely