OMC transom shift cable & ESA

[stevea661]

I replaced the transom shift cable due to hard shifting and too much load, causing the ESA to improperly engauge. Prior to change ESA would activate with the drive removed from the boat. Stupid Question, now the ESA does not engauge when the remote control is shifted and the drive is removed. I belive there is not enough load with the drive off to cause the ESA to engauge. I also belive this is normal. Just a note every thing is properly adjusted as per Stuart and my OMC factory manual. I also double checked measurments on the belcrank in foward neutral and reverse against the drive while on the stand, it's all good. I just want some reassurance from someone who knows before I install the drive that so far I'm good. I do have five extra drive gaskets just in case. I just don't want to have to use em. Thanks in advance.

 

[Howard Sterndrive]

Re: OMC transom shift cable & ESA

the ESA does not engauge when the remote control is shifted and the drive is removed. I belive there is not enough load with the drive off to cause the ESA to engauge. I also belive this is normal.

in my best Ed McMahon:

you are corrrrect sir

that is normal

 

[stevea661]

Re: OMC transom shift cable & ESA

Thank you!

 

[HT32BSX115]

Re: OMC transom shift cable & ESA

Stupid Question, now the ESA does not engauge when the remote control is shifted and the drive is removed. I belive there is not enough load with the drive off to cause the ESA to engauge. I also belive this is normal. Just a note every thing is properly adjusted as per Stuart and my OMC factory manual.

not stupid at all!!

in my best Ed McMahon:

you are corrrrect sir

that is normal Today 09:19 AM

DITTOS!!!


I am a "Ditto Head" here...... the ESA will not activate with the drive removed....


I'll also take it a step further and say that the ESA also SHOULD NOT activate with the drive on the boat running on the trailer either.

The drive should shift easily into and out of gear when the prop IS NOT torque-loaded (I.E. running on "Muffs" on the trailer).


It should also not activate when you put it in gear since there's no real impediment to moving the lower shift cable into either FWD or REV.......in or out of water.


When the prop is loaded (in the water), there is considerable torque on the shift dogs and they're "under-cut" such that torque holds them together with considerable force.

(OMC even had a recall 80's to replace the shift dogs with units that even a "steeper" undercut to increase the force required because they thought there wasn't enough to hold them together!)


When you attempt to push or pull the lower shift cable out of gear, the force required is then sufficient to overcome the mechanical advantage and springs on the shift plate and micro-switches operating the ESA.

The ESA then provides "stumbling" which briefly reduces torque enough to separate the "dogs"



Cheers,


Rick

 

[stevea661]

Re: OMC transom shift cable & ESA

The engineer that thought the system up must have been into geometry and physics and was trying to impress someone. The way merc did it just seems way less complicated. I was getting ready to run wires from the esa up the the controll and manually engauge it when required, while shifting gears. We will see how it works, I may still do this. Rick, apparently you also are familiar with these drives. If you have one I suppose you have to be, because no one else likes to work on them

 

[sea wolf]

Re: OMC transom shift cable & ESA

The engineer that thought the system up must have been into geometry and physics and was trying to impress someone. The way merc did it just seems way less complicated. I was getting ready to run wires from the esa up the the controll and manually engauge it when required, while shifting gears. We will see how it works, I may still do this. Rick, apparently you also are familiar with these drives. If you have one I suppose you have to be, because no one else likes to work on them

You got that right. That's what put OMC into bankruptcy. No one wants to work on them because the shift adjustments are too complicated & time consuming. And if the shop gets it wrong, then they're on the hook. Where I live there's only 1 shop within a 40-50 mile radius that will work on an OMC. The rest of the shops just don't want to be bothered. They don't want the liability.

 

[HT32BSX115]

Re: OMC transom shift cable & ESA

Rick, apparently you also are familiar with these drives. If you have one I suppose you have to be, because no one else likes to work on them

Nah.....my signature says it all!

87 Four Winns 211 Liberator 97 454/Bravo III (with closed cooling)
I use SAE xx zzzzz oil and have never had a problem!!!
Formerly PLAGUED by a 1987 OMC 460 King Kobra

The engineer that thought the system up must have been into geometry and physics and was trying to impress someone.....

Well, I don't know.....I am an Electrical Engineer by training and I was somewhat impressed........

The clutch dogs do a very specific "thing" because of the undercut (at a degree that OMC initially thought was inadequate), are undercut SPECIFICALLY to prevent then from inadvertently coming apart (because when they do something frequently breaks!)

The ESA was a pretty good idea. Merc clutch dogs, I suspect, are either not cut at such an extreme angle and/or are a little "longer" to help them stay together...... so a simple ignition-interrupt switch seems adequate.

The best "fix" is the Cone-clutch that Volvo and Mercruiser (Bravo) now uses. Very little "out-of-gear" force is required to get them apart......

After I removed the Cobra from my Liberator, one of the first things I sold was the ESA! followed by the non-existent Drive Coupler!!

All totaled, I got $3400 for everything OMC from that boat!!


If you're going to work on yours.....make sure you have the right-year(OEM) OMC service manual.

 

[stevea661]

Re: OMC transom shift cable & ESA

The manual I have is the omc manual for my 86. the question I have is that it shows the old style engine mounted shift assembly, kw-ar. It has been upgraded to the gd-rg style as on 1990 and up models. I do not have the up date in the manual. My manual stated the measurment on the engine end of the transom shift cable, in neutral, with the belcrank at 90 degrees is 6 1/2" from the center of the trunnion to the center of the shift pin hole. The only dimension Mr hasting gives is 7 5/8" from the shift pin hole to the edge of the cable crimp. I used both measurements. Does anyone know why the new procedure does not give a measurement from the center of the trunnion to the center of the shift pin hole? Am I missing something? This seems critical. I just don't want to have to pull the drive off again because I missed something. Although I'm getting really good at it. Thanks in advance.

 

[HT32BSX115]

Re: OMC transom shift cable & ESA

Mine was an 87 and I never had any problems getting it into and out of gear.

It was not upgraded to a newer shift plate but it did have the red cable (as all of them should have now)

You're probably going to have to do some searching to locate the newer shift-cable "movement" dimensions.

The bottom line of what I got out of the Hastings stuff was, that the (lower shift) cable movement from neutral to FWD and/or neutral to REV, must be approx the same.


I am glad that thing is gone.......


Where do you go boating from Tehachapi? (I used to live in Taft)

 

[stevea661]

Re: OMC transom shift cable & ESA

Ok Rick, I'll bolt the drive on without the gasket and see what the throw is from neutral to foward and neutral to reverse. If it works out I will remove and reinstall with a gasket and water test it. We launch out of marina del ray, and oxnard mostly, sometimes down to sandiego. It just depends. Some times to lake pyramid for testing repairs, it's the closest. like always thanks for the input Rick.