OMC drive coupling alternatives

[mrlassi1]

I'm restoring a 1976 AMF Crestliner with an OMC 190 Striger drive. The drive coupling that mounts to the flywheel/crank is worn badly as well as the intermediate drive shaft splines.

Are you aware of alternative couplings or mods that can be made to these or is my best option to find replacements on e-bay? I like the design of Mercrusier's coupling with its shock insert and grease fitting.

Thank you.

 

[Bt Doctur]

Re: OMC drive coupling alternatives

Now, is it a Stringer or a Cobra?. Intermediate splines?
you mention the merc coupler .

 

[mrlassi1]

Re: OMC drive coupling alternatives

Thanks Bt Doctur - Definately a "stringer" drive. I mention the Merc coupler due to its design.

 

[WizeOne]

Re: OMC drive coupling alternatives

Get the later hydro mechanical or full mechanical shaft and coupler. There are fewer splines but they are beefier. You'll either need to get the shaft with the bearings on it or have yours pressed off then on to the new one.

Make sure you grab the right coupler for your motor. Ford and chevs are different.

 

[mrlassi1]

Re: OMC drive coupling alternatives

Thank you for your posts. I ended up buying a mated coupler and shaft on e-bay. This coupler was an improved design with a cap on the engine side and an 0-ring on the outdrive side. It should hold grease better than the earlier design that relied only on the spline band on the shaft and was open on the engine side.

 

[mrlassi1]

Re: OMC drive coupling alternatives

Ouch! I was warned that due to the many variations OMC made on these shafts to be sure the spline and length were correct for my application. I was so pleased with the near-perfect condition and reasonable price of the used parts I bought off e-bay I never bothered to verify the shaft length. Since I bought a mated coupling and drive shaft I knew the splines would match.

Upon assembly I learned that the length was wrong. The "like new" shaft was ~1" too short and would not even engage the drive coupler when the intermediate drive was mounted on the rear of the engine. If he were still living my dad would have said, "son, there are some lessons you just have to buy". How true, how true...

I will go forward with the old shaft and coupling (cleaned and well greased with new seals).

Hmmm, now I have something to sell....

 

[Howard Sterndrive]

Re: OMC drive coupling alternatives

never seen this before-the parts listing shows two different parts based on model suffix:

0908680 COUPLING,Driveshaft. MODELS WITH "ALL" SUFFIX ONLY 1 $584.90 USD Limited

0980993 COUPLING ASSY. MODELS WITH "M" SUFFIX ONLY 1
$287.44 USD Available

 

[mrlassi1]

Re: OMC drive coupling alternatives

Howard,

My drive info is as follows: Model # 980709 Serial# W 75210

What part of this is considered the suffix information?

Thank you.

 

[Howard Sterndrive]

Re: OMC drive coupling alternatives

suffix usually appears on a tag on the engine somewhere I think.

 

[mrlassi1]

Re: OMC drive coupling alternatives

My worn drive coupling and shaft splines worked for a while. Last weekend I lost power and could hear the coupling slipping in the intermediate drive. I've pulled the engine and intermediate drive and am going to adapt the shorter intermediate driveshaft I already have on hand by making a spacer to go between the coupler and the engine crankshaft.

The overall shaft is ~1" shorter than the original and has 20 splines instead of 25 as were on the original. I'm planning to make the spacer from the flywheel end of an old Ford 302 crankshaft. A local machine shop will make the modifications needed for the spacer. I'll also use longer bolts. From the looks of the opening in the front of the intermediate drive there should be plenty of room for the "spaced out" coupler.

I'll make some pictures and let you know how it works.

 

[Howard Sterndrive]

Re: OMC drive coupling alternatives

guess you'll have to use rolling torque to shim the seal/cover to get the proper bearing preload (freeload?)
seem to recall a special tool for that, but an optional rolling method as long as engine is out. And it's best not to mix and match bearing cups and cones, so you'll want to press the old cups off the old shaft or buy new bearings.

 

[metalwizard]

Re: OMC drive coupling alternatives

Ouch! I was warned that due to the many variations OMC made on these shafts to be sure the spline and length were correct for my application. I was so pleased with the near-perfect condition and reasonable price of the used parts I bought off e-bay I never bothered to verify the shaft length. Since I bought a mated coupling and drive shaft I knew the splines would match.

Upon assembly I learned that the length was wrong. The "like new" shaft was ~1" too short and would not even engage the drive coupler when the intermediate drive was mounted on the rear of the engine. If he were still living my dad would have said, "son, there are some lessons you just have to buy". How true, how true...

I will go forward with the old shaft and coupling (cleaned and well greased with new seals).

Hmmm, now I have something to sell....

YOu ought to PM me with what you have. I am in need of an intermediate housing. I bought one and ended up with one with the WRONG splines.. (to many variances on these things)

Maybe what I have you can use. and visa verse. The one I bought supposedly came off of a V8 ford.

 

[mrlassi1]

Re: OMC drive coupling alternatives

Liberty's intermediate drive shaft and coupling replacement was a success. Here are a few photos of the spacer I had made in order to use the newer shaft and coupling. A local machine shop turned the spacer from a peice of Ford 302 crankshaft I brought to him.

 

[mrlassi1]

Re: OMC drive coupling alternatives

And a couple more photos of the spacer and shaft installed.

 

[zbnutcase]

Re: OMC drive coupling alternatives

Should work fine. I had a spacer made once to use a Merc coupler in a 2pc main seal 5.7 Cobra, as that coupler was on terminal backorder from OMC at the time. I used studs instead of bolts.