mariner tiller bolt question

[blakes52]

(engine is a 1999 mariner 135 opti SN:0G805271)i am replacing the steering system on my boat and the bolt that holds the steering arm of the hydraulic cylinder to the tiller was completely seized to the motor. long story short, after an hour of trying the bolt snapped off leaving the other half in the engine. the bolt was stainless and the tiller piece i believe is cast iron (based on some other post). i was originally going to try and drill out the bolt but if the piece isnt treaded i might try to just beat it out with the trusty hammer. Is that part of the motor threaded? See pics thanks!
IMG_20190429_114258.jpgIMG_20190429_114308.jpg

[blackboat]

It's threaded.That's going to be a tough one! Doesn't look like you can get a drill in there without everything coming apart but if you do drill,get a new carbide bit.You might try grinding the top of the bolt flush with the tiller or even below flush with a small die grinder type stone.Heat it up, melt some candle wax on the top and try screwing it on through with a pair of vice grips.Lot of ways to get that out but mostly when the part is off the motor.
Good luck!

[OldTimer57]

Isn't there usually a lock nut on the BOTTOM of that bolt?

[csurp]

I have half a memory of seeing a tiller handle bolted to the two holes on the front of that part. Maybe one of the "Big Tiller" type options.

edit OOPS you were not talking about the tiller handle sorry

[OldTimer57]

My thinking was if the lock nut is still there, no wonder the bolt broke. And if the nut is loosened, the entire thing will probably back right out from the bottom...

[blakes52]

thanks for the answers. i had to remove the lower cowling cover to work on it the first time. there was a lock nut below but i was able to remove it. i worked on that thing forever... might try to heat a little before i try and drill it out

[OldTimer57]

Once the lock nut is removed, you ought to be able to remove the remainder with a good pair of pliers. Probably want to try to screw it in from the bottom and out the top since the top of it was broken off and probably distorted. Unless you really twisted/distorted the bolt threads badly.

As far as the heat goes, be careful. Gas is REAL close by. :)

[lpugh]

thanks for the answers. i had to remove the lower cowling cover to work on it the first time. there was a lock nut below but i was able to remove it. i worked on that thing forever... might try to heat a little before i try and drill it out

Before or after it broke? If removed after this may not be all that tough to remove

[blakes52]

the lock nut was removed before the bolt snapped

[blackboat]

The bolt has obviously seized in the hole.Do what I said in post 2.If the tiller is iron,find a body or repair shop that has a magnetic induction heater.Have them heat the end cherry red and screw it out from the bottom.These heaters are super fast...no flames or collateral damage like a torch. Hole threads won't be damaged but you will have to do a little paint touch up. You might try double nutting the bolt instead of the Vise grips deal.In your situation,the mag heater doesn't affect stainless so the bolt itself doesn't heat,only the iron around it,which is what you're looking for.

[lpugh]

The bolt has obviously seized in the hole.Do what I said in post 2.If the tiller is iron,find a body or repair shop that has a magnetic induction heater.Have them heat the end cherry red and screw it out from the bottom.These heaters are super fast...no flames or collateral damage like a torch. Hole threads won't be damaged but you will have to do a little paint touch up. You might try double nutting the bolt instead of the Vise grips deal.In your situation,the mag heater doesn't affect stainless so the bolt itself doesn't heat,only the iron around it,which is what you're looking for.

WARNING:

Don't do this as it very well may cause internal stress when cooling that could result in a broken tiller putting you in to the fastest u turn you can imagine and you will no longer be in the boat. Never weld on steering components or heat them above 500 degrees, It would require a oven to slowly reduce the temp over at least four hour time frame to stress relieve it.
Find a machinist in your area that will have the right tool to remove it.

There was several methods of freeing up that bolt before it was broke, dont go from bad to worse

[blackboat]

WARNING:

Don't do this as it very well may cause internal stress when cooling that could result in a broken tiller putting you in to the fastest u turn you can imagine and you will no longer be in the boat. Never weld on steering components or heat them above 500 degrees, It would require a oven to slowly reduce the temp over at least four hour time frame to stress relieve it.
Find a machinist in your area that will have the right tool to remove it.

There was several methods of freeing up that bolt before it was broke, dont go from bad to worse

Should let this rest but you couldn't be more wrong. You are confusing this part with automotive steering components that may be forged or heat treated. This part was cast and air cooled or at best annealed... and heating and air cooling at room temp may actually REDUCE stress and cause no problems whatsoever.

[lpugh]

Should let this rest but you couldn't be more wrong. You are confusing this part with automotive steering components that may be forged or heat treated. This part was cast and air cooled or at best annealed... and heating and air cooling at room temp may actually REDUCE stress and cause no problems whatsoever.

Not unless the complete assembly is heated and cooled at the same rate, if it is made with a air harden alloy as many parts are, it will become very brittle if not cooled slowly
I don't have any idea what alloy they used or heat treating process of that part and I doubt you know that either, It can be removed with out risk
Are you willing to bet some ones life on your beliefs on this matter

[blakes52]

Good news! i was able to get it out. threads on the tiller piece are still there and arent stripped. tried to double nut the reverse the bolt out but i couldnt get it free. finally decided to dremel the top flush and drill it out. started out very small and stepped up very slowly. once i felt comfortable i was going to be able to drill it out completely i decided to try and undo the bolt with a pipe wrench. several tries it finally moved and was able to back it out leaving the threads behind. thank you all for the advice!

[blakes52]

f2b10aad-eff4-40bb-aa5f-fb2b56f77c21~01.jpg

[lpugh]

Good job, be sure you do not use just any bolt as a replacement. Get a genuine Mercury tiller bolt an lock nut. This is very important.​ They are not cheap

[blakes52]

thanks i am replacing the whole steering system with uflex so everything will be new! new!

[lpugh]

You will love that Uflex, far better than sea star