Tilt/trim woes. Steel pin stuck/seized inside aluminum

[jaykibo]

Hi everyone,

My tilt trim motor is giving up. I figured before it gives up entirely I replace it.
The unit is from a 1978 Evinrude (model 115893) V4 Crossflow 115hp. They use the 3-wire tilt/trim assembly.

I am trying to remove the entire assembly so I can work on it on my bench. The 3-wire motor has 3 bolts holding it in place and once of them can only be accessed if you remove the assembly (or take the entire engine off the boat, which I am not willing to do as it hasn't been done in many years and I don't want to risk introducing any points where water may enter the transom. It's an old boat).
I was easily able to pull out the 6 bolts holding the assembly in place, but I can't push out the pin that is the pivot for the top tilt/trim hydraulic piston to the engine (see pics). The pin is usually held in place by a split pin, they came out easily. But I can't hammer the darn thing through!

Photo Album - Imgur

I have taken off the weight of the engine by hoisting it up by my rafters (using block and tackle set). I have been able to successfully un-stuck it over the past few days of constantly spraying WD40 and penetrating lube and tapping it. I can smash it hard enough with a hammer and it edges out, but as soon as it gets to the point you see in the pictures I can't make it budge anymore!
I have tried welding a dollop of metal to the end and smashing that and that worked to some degree, but I can't keep doing that all the way through.
I have tried heating up the ally around the pin and tapping it, but again no success. I have already tried using my pneumatic air hammer (like this one: http://www.maxxeshop.com/content/im...impact-pneumatic-chipping-hammer-air-saw.jpeg) but again this didn't help.
It's well and truly stuck! ARGH! Please help!

Does anyone have any ideas?

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

Grabbing it with vice grips on the protruding end and trying to twist it did not help either.

The problem is now that there is nothing protruding from the end I am hammering I cannot put as much force on the pin to make it move. I am using a rod I hold in place with my hand and hammering the other end of that rod, but I just can't get the same amount of force as I can hammering directly on to the pin.

I am thinking tomorrow I will try welding a rod to the pin, effectively _extending_ the pin. That will allow me to smash the end of the rod with a hammer and hopefully allow me to add more force.
Another option is to drill and tap a bolt in to the middle and then attempt to use an impact driver to spin the pin. Loosening it up. But I'm thinking this just may end up with a snapped bolt.

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

OK. I'm thinking tomorrow (it's almost midnight now) I will weld a larger washer on to the protruding end. The washer will be larger than the pin so that I can weld it from behind and make sure I got a nice and strong weld. Then ill get a very large nut and weld that on to the washer. This should be give plenty of strength in the welds so that I can use an impact wrench and spin the pin while tapping it from the other end.
My only problem is.... the MIG welder I have uses mild steel wire which rusts. I have stainless TIG welding rods, but I am not very good at TIG yet so I don't know if I will be able to weld it strong enough. If I end up using the MIG I may need to scrap the pin if I can't cut off all the weld without damaging the pin.

hmmm... I am open to other ideas

 

[RRitt]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

if you mushroom the end of the shaft then it won't go through. I usually use a grinder and make the shaft tapered. if the shaft has to be replaced and another is not handy then I cut one from SS rod and hold in place with cotter pins.

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

if you mushroom the end of the shaft then it won't go through. I usually use a grinder and make the shaft tapered. if the shaft has to be replaced and another is not handy then I cut one from SS rod and hold in place with cotter pins.

Hey RRitt. Yeh, I forgot to mention that I noticed I had mushroomed the pin and had to grind it down to a taper using my dremel. This was done on both sides and using the spot weld I mentioned in my first post I was able to punch the pin through about 2mm (~0.1") past the face of the aluminum. But increasing the size of the weld so that it is past the face of the aluminum (can therefore can be hit directly with a hammer) is not very scalable.

 

[RRitt]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

if it has a taper and is moving 1/2" then it should get easier and easier. try some aluminum lubricant like they make for screen doors in florida. put a 1/2" bolt into a pair of vice grips and hit the end of bolt with hammer. back and forth. each time it should go a little further until is just pops out.

 

[Will Bark]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

Don't know if it makes a difference. but I started mine out from the starboard side and used a mild steel drift that I hit with a 2lb short handled sledge hammer; took several really good blows before it started out and then out she came. Good luck

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

Thanks for the advice guys.
I went to the hardware store this morning and picked up a 2.5lbs mallet. I tried putting a bolt in vice grips and smashing that. At first the bolt kept drifting so I put a spot weld to keep it in place. Then smashed the daylights out of it but ended up bending the bolt. The pin didn't move at all! The bolt cant be shorter than what you see in the pic otherwise the hammer head wouldn't be able to hit it.

I've decided to bring in the big guns. I've welded a washer on to the protruding end and then a 14mm nut on to that. I am now waiting for the weld and the pin to cool before I heat up the ally around the pin and try turning it with my impact wrench. The welds look ugly but its the best I could do in such a tight position. I made sure it was clean and I bumped up the juice on the welder and made nice and fat welds.
I gave it a test run with my impact driver, but no movement. I don't want to risk weakening the welds while it's warm so i'll give it a hit with my impact wrench (pneumatic) an hour from now.

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

Oh boy..... the welds certainly were strong enough! But after heating up the ally for 5 minutes and then using my impact wrench the nuts ridges got cleaned straight off! It became a round nut! I tried welding another (bigger) nut on to the rounded nut and that one broke off. Not even at the end, but the body of the nut where there was no weld!
One thing is for certain, this pin is not about to begin spinning. I have to go back to trying to knock it out....

Back to the 'ol drawing board

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

SUCCESS!

I called in the cavalry (my father in law) who used a mallet and a wider punch (the wider punch is what helped A LOT.. making sure it covered the surface of the pin entirely). I then applied heat to the knuckle and while he hammered it out. We also made a wooden jig/bracket to hold the pin straight.

The punch you see in the pics was too narrow. We ended up getting a 15mm wide punch which worked a treat.

 

[jaykibo]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

SUCCESS!

Just to close off the loop on this thread, below is how I solved the issue.

I called in the cavalry (my father in law) who used a mallet and a wider punch (the wider punch is what helped A LOT.. making sure it covered the surface of the pin entirely). I then applied heat to the knuckle and while he hammered it out. We also made a wooden jig/bracket to hold the punch straight.

The pin was slightly bent (which was why it was so hard to get out!), likely due to normal use over the years. I will need to replace the pin.

The punch you see in the pics was too narrow. We ended up getting a 15mm wide punch which worked a treat.
View attachment 214048
View attachment 214049
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View attachment 214051

 

[Will Bark]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

Thanks for showing your success!

 

[pn]

Re: Tilt/trim woes. Steel pin stuck/seized inside aluminum

trooper