Steering bolt

[mach351]

With recent sad news of steering bolt failures - I think its time to replace mine - wheres a good place to find new bolts? Ive always just found "old" bolts that would "work" - enough of that!

Any thoughts?

[03bignasty]

I think we're all guilty of running them too long. We need to start replacing them yearly. It's cheap insurance.

[150aintenuff]

ARP SS bolt.... available at any Auto parts source.... every year is a good idea.... with this thred im gettin a new one for myself... and 2 new bolts for my steering tyebars on the dual cable...

[mr_velocity]

Wouldn't happen to have the ARP part number

[ssent]

I always heard steering linkage bolts should come from merc or omc as exact replacement for that specific bolt. I've always got mine from omc dealer for specific replacement. What grade of bolts are the arps?

[Fish]

here is the mercury part number P/N 10-849838 which is 1.25" long.

Here is a thread that has some good info: http://forums.screamandfly.com/forums/showthread.php?t=125065&highlight=arp+bolt

I was looking for a replacement this morning after I read the story about Byron.

Fish

[Tom Foley]

It is insane that this part is so overlooked. Is it actually possible for this bolt to shear off if it is properly installed , red locktited and the jam nut as well ? The stainless ARP bolt is a nice one and costs around 13 - 15 dollars where a cad plated grade 8 bolt is .45 cents but subject to corrosion . Some strength numbers would be of interest for comparison here .

[150aintenuff]

If you look on the top of the Merc bolt it has ARP stamped on it....... so there HAS to be a ARP ## that doesnt have the markup that the merc one does... will see if I can drum it up

[150aintenuff]

It is insane that this part is so overlooked. Is it actually possible for this bolt to shear off if it is properly installed , red locktited and the jam nut as well ? The stainless ARP bolt is a nice one and costs around 13 - 15 dollars where a cad plated grade 8 bolt is .45 cents but subject to corrosion . Some strength numbers would be of interest for comparison here .
ARP stainelss bolts have 190000-200000 tensel strength

[j_martin]

Stainless has a way of changing characteristics over time as it is repeatedly stressed. Sometimes the result is predictable, sometimes not. I'm looking for replacements also.

I don't know where 150 got his info, but the tables I've seen list grade 5 at 75 ksi ultimate shear strength, grade 8 at 91, and ARP at 95.

I've gotten into the habit of grabbing the engine and giving it a good shake when I'm putting the plugs in the boat for a launch, just to be sure that steering, motor mounts, transom bolts, etc. are all reasonably tight.

I saw a skeeter bassboat going down the road yesterday with a yamaha 150 on it, flopping side to side a little on every bump. That's an accident looking for a place to happen.

[transomstand]

This problem has existed for years. Personally, I'm amazed with all the innovative people around here no one has come up with a solution. You need redundancy, two bolts solves the problem. My tiller arm has two holes, so it's easy, I'm connected with 2 bolts, my cables are completely independant of each other. Total failure of one side means little.
Problem is, different mounting systems and tiller arms don't allow that, but somebody needs to come up with a fix for this. It's just too important to allow that single point failure to have such catastrophic results.

Pete

[1BadAction]

Its a non-issue if everyone replaces these bolts like they should be doing. Don't over tq them, don't tighten them more than once or twice, dont use "just any old bolt", and don't run with so much tq on the wheel that you gotta put all your strength in it to keep it straight.

ARP rates these bolts (meaning the ones merc sells for steering, and they arent just any old stainless) to near 200,000 shear, but if they are over tq'd or loose they could fail at 1/4 of that, and thats info straight from ARP. Truthfully, with some of the bolts I have seen holding 225hp+ outboards I'm surprised more of them haven't broken.

[j_martin]

Arp is a brand name.

I checked briefly with our head mechanical engineer (ArrowTank), and most stainless bolts are rated near grade 8 IF they are stress heat treated. 190 k seems a bit high.

ARP is a good name. I'd not hesitate to rely on their product.

If I can come up with some more definitive info, I'll put it up.

John

[1BadAction]

Arp is a brand name.

yea, and thats who makes the tiller arm bolt for mercury.

[Pro300x24LD]

Can someone provide some details of said bolt and give me some help as to what to look for?

I am running a 300x with an offshore mid, I have full hydraulic steering with the ram mount on the side of the engine and wingplate.

I don't want this to happen to me and I want to buy the "bolt" if I should replace the one that is on there since I have no clue how long it's been there.

Thanks

[BarryStrawn]

ARP rates their "Stainless 300" alloy at 170,000 psi in tension. SAE Grade 8 would generally be considered 150,000 psi. Note that the tiller bolt is used single shear, and that would be rated at 3/5 of tension.

I suppose the Mercury part could be the ARP proprietary A286, Inconel, or other super alloy but I doubt it at the retail price. You can get ARP standard SAE dimension bolts in blister packs at most speed shops. Or contact them at www.arp-bolts.com (http://www.arp-bolts.com) and they will make anything you want.

UP_ROKTOY - If you have side mount steering, you don't have a bolt in the tiller arm to worry about. Check with Latham, Marine Machine, IMCO or whoever made your steering for an inspection or maintenance recomendation.

[Promax1R]

Does anyone have the ARP part #?:confused:

[ProComp]

Bad bolt on the left, good one on the right. The Merc one is $28.50 Cdn up here. Crazy but whats your safety worth right? No biggy. The bad one looks like it has kind of an 8 on the top. Came off my 96 Rocket, probably been on there since new. Yikes.

[mach351]

I just went and ordered one - 15 bucks and 2 for the locknut.:D

[j_martin]

The bad one looks like a farm store bolt (grade 2). It could be something else, but most of the other rating systems would put it at 80k tensile, which is in the grade 2 range.

I don't know what 3xx alloy ARP is using, but 316 has a pretty high tensile strength, but a low yield strength. I think that is because stainless does some pretty wierd things when it's stressed and flexed. 304 and 306 likewise, but a little higher yield strengths. None of them are any where near the 180k mark. The only ones I see in that range are chrome moly steels, like they use for rod bolts.

I think my tact is going to be to put in a grade 8 bolt, well greased to limit corrosion. The relatively low cost should encourage me to discard it at least once per year and thus keep a good eye on the whole system. The 2 bolts on the end of the cables are also going on to the preventative maintenance list.

John



Bad bolt on the left, good one on the right. The Merc one is $28.50 Cdn up here. Crazy but whats your safety worth right? No biggy. The bad one looks like it has kind of an 8 on the top. Came off my 96 Rocket, probably been on there since new. Yikes.

[Tom Foley]

Don't grease the area around the threads where the locktite will go ! Spray it with Boshield T-9 and that will keep salt and other contaminants away . LPS also has a very similar product .

[1BadAction]

or better yet, use the correct bolt in the first place and you wont need to worry about corrosion.

[pyro]

Mine still has the original bolt from 1989.

[j_martin]

Just looked at all the bolts on mine. They seem to be normal A2 stainless (304 alloy) which would be about as strong as grade 5 steel. They are worn a bit, I would say normal for the 18 years they've been on the boat.

The high strength stainless bolt on the market is called grade 410 (C1) hardened and tempered. It's about 180,000 psi tensile. They would be about twice as strong as the stock bolts. They stick to a magnet.

I don't see how a properly tightened stock bolt in good shape would fail, but I sure see how it would quickly wear away and fail if it was allowed to loosen. I think the big thing here is keeping an eye on the condition of the steering hardware.

hope it helps
John

[Ron V]

It bothers me that our safety relies on that one bolt, that nobody has addressed this, and there doesn't seem to be a good way around it on motors with yokes that only allow one link arm and if you have same-side entry cables. I agree that replacing the bolt periodically and just keeping a good eye on it to make sure it is tight is probably the best practice.

What is spooky about this incident is that the same exact thing is what caused Kurt Graf to go through the side of his boat a few years ago, and his boat was also a Euro. This especially bothers me because the steering system in my boat was from a Euro and I used the bolt that was in it. Think I might order a new bolt. Remember though, even if you change the bolt, the other end of the link arm is still the same size (3/8 - 24 thread) and I believe it is the same or similar material.

Still makes me wonder though if some of these bolts that break are the result of something else. For example, does the boat hit something, blow out, etc., and cause a violent hook which snaps the bolt from the sudden load. Like what came first, the chicken or the egg?

[j_martin]

Stainless steels work harden, and can also develop corrosion stress cracking over time. Carbon steels don't work harden, but they are more subject to corrosion than stainless. It would be interesting to find the broken pieces and have them professionally inspected.

Normally I wouldn't expect a lot of strain on the bolt compared to what it can take, but if you have a slightly loose bolt, or the ball joint that it is holding down gets loose, now you add an impact factor that is probably significant. It's kinda like when a rod starts to get loose, it'll get real loose (like gone) in a hurry. If a boat isn't well behaved, and likes to beat on the steering chine walking, you need to watch the wear and tear more closely.

We've seen some real bad boating accidents lately caused by steering failures, and also structual failure of the hull. Lack of judgement, such as running a known damaged hull at high speed into heavy seas contributes to this.

You can't guarantee safety, but you can do what you know you should to augment it. We need to both practice and preach preventative maintenance and systematic inspection by owners, just like an airplane gets systematically inspected every time it goes up.

[euro scott]

just replaced my steering bolt and nut that i got from Diamond, and because i have a washer to shim the sea star pro for a clearance issue the bolt that marty ship's has a washer under the head that doesnt come off with out grinding, and its a pain, so if you have a spacer washer there is not enough thread left to engage the nylock.. so before ordering check for a spacer washer and order one with out the washer on the bolt

[flabum1017]

Stainless steels work harden, and can also develop corrosion stress cracking over time. Carbon steels don't work harden, but they are more subject to corrosion than stainless. It would be interesting to find the broken pieces and have them professionally inspected.

Normally I wouldn't expect a lot of strain on the bolt compared to what it can take, but if you have a slightly loose bolt, or the ball joint that it is holding down gets loose, now you add an impact factor that is probably significant. It's kinda like when a rod starts to get loose, it'll get real loose (like gone) in a hurry. If a boat isn't well behaved, and likes to beat on the steering chine walking, you need to watch the wear and tear more closely.

We've seen some real bad boating accidents lately caused by steering failures, and also structual failure of the hull. Lack of judgement, such as running a known damaged hull at high speed into heavy seas contributes to this.

You can't guarantee safety, but you can do what you know you should to augment it. We need to both practice and preach preventative maintenance and systematic inspection by owners, just like an airplane gets systematically inspected every time it goes up.


J Martin is on track here. The loads that are applied to the steering bolts should come nowhere near the breking point if everything is set up well. Loose bolts will be work hardened in no time flat with the hammering effect from the vibrations of the engine, over-torqued bolts will shear between the threads due to stretch and corrosion will take it's toll over time. I have never seen a steering bolt fail that was properly installed on any standard family or fish boat and those boats usually never have their bolts replaced. Our high performance boats are a different animal and require close attention to detail when working on every piece. And as everyone here agrees, that bolt is a critical part that should be replaced and inspected regularly.

If there are bolts shearing a lot recently, then maybe we need to see if they are all the same bolt and contact the manufacterer to see if there is a problem somewhere. Manufacturing defects are not unheard of.

[Techno]

If you change the bolt every year why not plain steel? Is there a problem with this if your not on salt water?
*plain steel meaning a decent steel bolt not a gr.0:D

[JohnR225]

You guys who are running the dual opposed steering cables use a system like this one right?

http://www.reynoldsracingmarine.com/images/sterlink.jpg

This one ties the steering block to the engine with five bolts… The three you can see on top (the bolt in the center being the single bolt you guys are referring to) and two cap bolts that come from the front, you can’t see in this picture.

[tony brimeyer]

Strong steering arm bolts are critical,but I had my tiller arm completely snap in two. Just imagine doing 60mph and the boat going from a straight forward motion to a hard right as fast a blink of an eye! Could've been alot worse at 85 mph.Guys, check your steering!

[JohnR225]

I too have heard of the tiller arms snapping.

For that reason I had a small gusset added to the 90 degree turn in the tiller arm even though the dual opposed steering uses two tiller arms, better safe then sorry.

[time warp]

I too have heard of the tiller arms snapping.

For that reason I had a small gusset added to the 90 degree turn in the tiller arm even though the dual opposed steering uses two tiller arms, better safe then sorry.

The tiller arm is the steel part on the motor that you are bolting your 5 bolts to, that's the part that breaks, havent heard of many steering link rods breaking. if you have figured out a way to reinforce the tiller arm could you please share pictures.

[JohnR225]

Dang, now that’s a whole new problem.

However that explains the reason for the safety steering yoke you can buy for around $100 for the 1 piece exhaust plates.

http://www.reynoldsracingmarine.com/images/safyoke2.jpg