How to keep outboard from flopping around on steering axis while trailering

[eli_lilly]

Hello,

I've seen the transom saver discussed to death but haven't really seen any mention of my personal concern, which is the flopping of my outboard on the steering axis while trailering. My boat is from the late 60s and uses the Teleflex inboard steering clamp block even though it is propelled by an outboard (the inboard clamp block is the one that gets connected to the transom by a single big-arse bolt through the transom). When I trailer (which I do with the motor up on the Johnnyrude latch) the motor bounces around slightly on the steering axis, which causes great force to be applied to the steering tube and the clamp block. I am not keen on this, and although it's been doing this for over a year now, it's really the one trailering situation that I am concerned about. I can't think of a good way to physically hold the motor straight (or even just cushion its return to the full-left or full-right rest position from a bounce) at the engine itself. Holding it straight from the steering wheel, via bungee, won't help as the same force will be exerted on the clamp block. Any ideas on how others deal with this, or would deal with it, is greatly appreciated.


Thanks,
-E

 

[Silvertip]

Re: How to keep outboard from flopping around on steering axis while trailering

A good transom saver does that for you.

 

[guy74]

Re: How to keep outboard from flopping around on steering axis while trailering

Use a good transom saver and a ratchet strap to hold the motor down on the transome saver. I use my power tilt to hold mine into the T-saver, but if you don't have power tilt use a nylon ratchet strap. The T-saver holds the motor strait as well as up and down.

 

[DJ]

Re: How to keep outboard from flopping around on steering axis while trailering

eli,

Re-read the threads.

The transom savers have a bungee cord that holds the engine down on the saver to stop vertical bounce. Some use a strap to hold the engine against the saver. The strap goes from the engine to the trailer frame.

A lot of us either bungee the engine or the steering wheel to stop it flopping to one side.

I just removed a set up, like yours, from a Boston Whaler. The transom saver worked fine as described above.

The way you are trailering it now is not good for the engine or the transom.

 

[eli_lilly]

Re: How to keep outboard from flopping around on steering axis while trailering

eli,
Re-read the threads.

The transom savers have a bungee cord that holds the engine down on the saver to stop vertical bounce. Some use a strap to hold the engine against the saver. The strap goes from the engine to the trailer frame.

If I use a saver, would that likely stop the side-to-side swivel as well? That is the part that I haven't seen discussed, only the saver's impact on up-and-down motion. Although I can already see how lowering the motor onto the saver would stop the stress against the steering tube and clamp block by moving the powerhead to a more horizontal position.


Thanks,
-E

 

[eli_lilly]

Re: How to keep outboard from flopping around on steering axis while trailering

Thanks everyone for the responses, I will get a transom saver. The Fulton one that iboats has is looking pretty good.

-E

 

[Chris1956]

Re: How to keep outboard from flopping around on steering axis while trailering

Eli, If you turn the motor all the way to one side and trim it up a bit, the weight of the motor should keep it there.

I do not think Transom Savers are at all necessary. My reasoning is that if a outboard or I/O can hold the LU in place against the full thrust of the motor(say 150HP), the hydraulics are plenty strong to hold the weight of the motor against a pothole or bump in the road. I therefore think they are overkill.

 

[Silvertip]

Re: How to keep outboard from flopping around on steering axis while trailering

There seems to be a misunderstanding of what forces a transom saver is designed to negate. Using the hydraulics of the trim system or a tilt-lock mechanism does one thing and one thing only -- it keeps the engine or drive tilted. That does absolutely nothing to negate the forces acting on the transom from the bouncing of the boat which causes twisting of the transom because of the long moment arm of the extended drive or lower unit. The transom saver ties the lower unit, the boat, and trailer frame into one unit. All of the forces are now transfered to the springs on the trailer and in the case of the hydraulics, eliminates stress on that as well. A transom saver with a relatively deep "V" block to support the drive will work best at keeping the motor from moving side to side. Whether you use a transom saver or not is a personal decision but if you look around, you'll them used by many of us who travel thousands of miles a year trailering boats at freeway speeds and often on less than ideal secondary roads. It's simply very inexpensive protection.

 

[MrBigStuff]

Re: How to keep outboard from flopping around on steering axis while trailering

That has to be one of the best, most concise arguments I have read to date on the subject Silvertip.

One other point to be made is the type of shock being applied. Where on the water will you get such an abrupt (rise time) and forceful impact as you will going over road imperfections like potholes and bumps? And that is again amplified by the lever arm of the weight extended back off the transom. In trailering mode, my OB is above the bracket that helps to stabilize the engine from lateral forces as well. When they cost like $20, to not use one is penny wise and pound foolish IMO.

 

[guy74]

Re: How to keep outboard from flopping around on steering axis while trailering

Well, the main point is, that reguardless to the fact of whether you need a T-saver to protect your transom, it certainly won't hurt your boat and it will stop the flopping from side to side that this thread is about. I use one on my boat, the motor doesn't move up, down, or steer to either side going down the road. I would hate to be without it.

My $.02

 

[Chris1956]

Re: How to keep outboard from flopping around on steering axis while trailering

Silvertip, I disagree with your reasoning on the twisting forces inherent to trailering a boat, versus using the motor's trim. When I am bouncing across the bay at 30 mph, with my 150HP engine trimmed up, the forces on the stern are far from static, yet my transom is strong enough to take it. First the motor is trying to lift 3000 pounds of boat or more off the surface of the bay, and next the boat is crashing back into the bay after coming off a wave, which unloads the transom of any force for a short while. Road travel can never be that taxing.

Another example is my low profile speedboat "glancing" from (small) wave crest to wave crest at 50+MPH. The boat and motor going airborn for a short interval indeed creates uneven forces on the transom.

Now if anyone still wants to buy a transom saver, which (I think) is unnecessary, it is their money!

 

[DJ]

Re: How to keep outboard from flopping around on steering axis while trailering

Silvertip, I disagree with your reasoning on the twisting forces inherent to trailering a boat, versus using the motor's trim. When I am bouncing across the bay at 30 mph, with my 150HP engine trimmed up, the forces on the stern are far from static, yet my transom is strong enough to take it. First the motor is trying to lift 3000 pounds of boat or more off the surface of the bay, and next the boat is crashing back into the bay after coming off a wave, which unloads the transom of any force for a short while. Road travel can never be that taxing.

Another example is my low profile speedboat "glancing" from (small) wave crest to wave crest at 50+MPH. The boat and motor going airborn for a short interval indeed creates uneven forces on the transom.

Now if anyone still wants to buy a transom saver, which (I think) is unnecessary, it is their money!

The transom is only HALF the story. The engine is not designed to take that kind of shock while in the UP position. I've seen enough broken trailering brackets and clamp brackets to prove it.

Transom savers really came into play when trailers became more low slung (read: bass boats). Trailers of yesteryear were pretty high, by todays standards. Most outboards were trailered with the engine down, which is fine, if you have the clearance. Also, many engines of yesteryear did not have tilt and trim.

I do not believe the originator, of the post, has power tilt and trim. If not, a transom saver is a good way to secure his engine for trailering.

I do not disagree that most power tilt and trim units can handle the stress if the engine is trailered with the engine in the TRIM range. You are not skipping across the waves with your engine in the TILT range of your trim and tilt. Above the trim range, you're pressing your luck. This especially applies to OMC/Bombardier engines with three ram TNT units.

One more thing to consider. The power tilt and trim unit has hydraulic pressure holding the engine up, or down. Essentially, the engine and transom become one via a fluid link, under pressure. That is NOT the case with an engine without power tilt and trim. It is the bouncing of the engine that wreaks havoc on the engine and transom.

With all that said. I still use one. I have seen an engine fall because of a hydraulic leak. By the time the owner caught it, the skeg and half the L/U bullet were gone. Read $$$$$. All that $25.00 could have prevented.

 

[Lakester]

Re: How to keep outboard from flopping around on steering axis while trailering

hello,

to me it is a basic law of physics, mechanics and angulation. so, imo... i think both silvertip and... chris56 are correct.

i am a proponent of the transom saver (ts), and have one. to me, the ts transfers unsprung weight loaded perpedicular to the transom via a bouncing outboard to the sprung trailer frame. what remains fwd and past the c/g of the mounted engine is now transfered vertically down thru the vertical component of the transom during bumps. i think this is a very good condition to have.

i agree an i/o has a l/u hanging on its transom, but it generally also its hull and transom are of a beefier design. it is structurally more sound per sq ft relative to weigh/forces applied. an o/b is usually a lighter design. true wave bouncing can unload and load the outboard's prop thrust, but within reason it is designed to do that. however, the average o/b is not designed to be jumping wakes and waves.

for me it is like bending metal. work hardening sets in if u bend it enuff... it becomes brittle and breaks. i think the tansom using a ts will be stronger over the years than the one not, given the forces of thrust application from bouncing. the unsprung o/b in tilted position up, just has a brutal moment arm out there, and that cannot be denied!! you cannot move a large rock with a 6" bar, but u sure can with a 6' bar!!

imo, the statement " First the motor is trying to lift 3000 pounds of boat or more off the surface of the bay," is a bit careless. the motor is not trying to lift that much weight, any more than a new car when floored is trying to lift all its weight. it may rock the ring n pinion gears up against that weight, but it takes a lot more hp to try to lift 3,000#s. like maybe 1,000 + hp! and traction, for once traction is lost, so goes the applied energy.

so to me jumping waves, and wakes, other than the occassional unavoidable event, is operating outside the design envelope. not using a ts is not taking advantage of optimum protection opportunities for the longest service life of the transom.

i will use my ts with a smile as i think it will put the forces of bounce down a vertical vector thru the transome rather than as a perpendicular force trying to flex the transom off the back of the boat.

imo, every smart boater trailering should use a ts if they care for maximum protection. if OK is good enuff, then nbd!

regards,

lakester

 

[eli_lilly]

Re: How to keep outboard from flopping around on steering axis while trailering

Eli, If you turn the motor all the way to one side and trim it up a bit, the weight of the motor should keep it there.

There are two problems when I trailer. The first is that the motor, when it is up and turned all the way to one side, is not resting against the transom bracket's full left or right stop. It is resting against the steering tube's travel limitation, and the steering tube is connected to the transom via a 3/4" bolt that runs through the transom, roughly 18" to the right of the outboard's transom bracket. The steering tube does not pass through the outboard's tilt tube as it does on most outboards, it connects from the front of the outboard to a ball joint swivel assembly mounted inside the transom off to the side of the motor.So the full weight of the motor (as if it was picked up on one side) is applied to the single bolt that holds this assembly in place.

The second problem is that the weight of the motor, in this position, is not really that much to keep it from moving on the steering axis, which applies even more force on the steering clamp block and the lone bolt.

I do not think Transom Savers are at all necessary. My reasoning is that if a outboard or I/O can hold the LU in place against the full thrust of the motor(say 150HP), the hydraulics are plenty strong to hold the weight of the motor against a pothole or bump in the road. I therefore think they are overkill.

I am not so much worried about my transom or the bouncing of the motor on the tilt axis. However, the effect of bouncing on the steering axis, while the motor is tilted up, has already bent the 3/4" bolt from the original steering clamp block. I assumed it was caused by old age and rust when I replaced it last year (I've only had the boat for a year) but in routine monitoring I now realize that an excessive amount of force is applied to the steering assembly when I trailer. When my outboard is tilted up, neither full left nor full right will rest the powerhead against the transom bracket, it always hits the travel limit of the steering tube first. This is my concern and what it seems that the transom saver will help.

DJ - I do have trim and tilt but you did nail it with the bass boat thing, that's exactly what my trailer is, although the boat is not a bass boat.


Thanks,
-E

 

[DJ]

Re: How to keep outboard from flopping around on steering axis while trailering

E,

Good luck with your addition. When you get a chance, post some pictures.

 

[Silvertip]

Re: How to keep outboard from flopping around on steering axis while trailering

Those that rely on hydraulics to hold the motor up are making a "leap of faith" especially if one regularly gets the prop out of the water and slams back into it full throttle. Hydraulics to fail -- generally at the worst possible time. As is obvious, there are those that feel transom savers are unnecessary just as there are those that feel seat belts in vehicles and helmets on four wheelers, snowmobiles and cycles are unnecessary. It's a safety device. You have the choice to use it or not. As someone once said "an ounce of prevention is worth a pound of cure!" Or the one I like is "pay me now or pay me a lot more later!" Ever seen an OMC outdrive that hit the pavement because the clutch retaining ring in the trim worm gear popped out and allowed the drive to drop? Or looked at aluminum fishing boat with welds on the transom supports? Those welds were required because the engine was flopping around on the transom which eventually stress cracked the support. The safest way to transport the rig is with the engine full down. This places the stresses in a vertical plane and the transom has a full support from below. Unfortunately, most trailers nowadays allow the boat to ride lower so the skeg would dig furrows in the road so that choice is not available. My New Years resolution will be calculate the forces at work on trailer boat transoms.

 

[boatmanjf]

Re: How to keep outboard from flopping around on steering axis while trailering

Put the engine on the tilt lock and ratchet strap it to both sides of the boat.


This trread became a discution on transom savers-----really wasn't the point.

Tilt the engine up and in the straight position....strap from engine to both sides of the boat with two straps...

Been doing this for years......Transom savers work but I end up loosing them or they fall apart. Straps have ALWAYS worked and haven't destroyed a transom yet.

 

[tashasdaddy]

Re: How to keep outboard from flopping around on steering axis while trailering

i totally disagree, the tilt lock is for beaching, shallow water, not for trailering. i've seen to many broken, bent tilt locks from trailering.

 

[rickdb1boat]

Re: How to keep outboard from flopping around on steering axis while trailering

I use the Lock N Stow. I've seen boats going down the road and hitting potholes and such. The transfer of shock from the trailer to the lower unit was enough for me to stop using traditional transom savers..

 

[BillP]

Re: How to keep outboard from flopping around on steering axis while trailering

I use the Lock N Stow. I've seen boats going down the road and hitting potholes and such. The transfer of shock from the trailer to the lower unit was enough for me to stop using traditional transom savers..

I agree. Follow a trailerboat on a road trip and watch it bounce around. Even on the flat smooth roads of Florida, trailers flex, straps stretch, boats move up/down/sideways away from the trailer...99% of the 16'+ trailerboats do it.

If anybody is interested in historical trivia...TS were marketed back in the mid 1950s and advertised to keep the motor from hitting the road.