OMC Fwd/Rev Gear Replacment

[dlktdr]

I am replacing the lower forward, reverse, clutch dog and pinion gear in the OMC cobra I have. I bought a heavy duty gear set from GLM. I need to properly shim the pinion gear so the gears properly mesh. OMC has a special jig to do this.
Does anyone know what the exact distance from the thrust plate to the pinion gear is supposed to be? And where they are measuring from on the pinion.. I really don't want to have to wait for the local shop and pay them as much as buying the jig myself...

Or any other method to figure this out??

 

[Don S]

Re: OMC Fwd/Rev Gear Replacment

There are special tools needed (Along with an OEM service manual) needed to properly shim any outdrive. Without them, it's impossible to do. That is why they made the special tools to begin with.

 

[a70eliminator]

Re: OMC Fwd/Rev Gear Replacment

I don't know specifics on the special OMC tools needed for setting up a gearset, but I wouldn't consider it impossible, Some special tools are simply geared to the flat rate mechanic, he sticks the tool in there and tightens a nut and he's done, time is money. I believe a talented individual that understands mechanics of a gearset may just be able to accomplish it without "the tool", maybe have to use several other tools, take 3 times as long but end up with the same backlash, same endplay, ect.
I've seen some special OMC tools that to me are nothing but a guage that can be substituted by other devices if you understand what the the end result needs to be. On the other hand I've not had the challenge of setting up an OMC gearset, Don more than likely has and knows exactly what it takes, I shouldn't even be questioning it, Sorry Don..

 

[dlktdr]

Re: OMC Fwd/Rev Gear Replacment

I understand there is a special tool for this, but the special tool is just a holder. I do have the OMC manual and they give every other dimension for measurement except this one.

I have more equipment available to me than most and most of the "special tools" are rather easy to build on your own.

The tool, from what I can see is just a mount. you place a gauge bar on the bottom and measure the distance to the rear of the pinion.. I went ahead and did it anyway making an assumption the old pinion was shimmed properly at the factory and I used that as a reference. It was easy enough to mount in my lathe and accurately measure. It should be damn close.

I would be easy enough to build this jig and with the hard to find service and parts I hope someone who owns one can measure it one day.