Mercruiser drive plate

[dazid1]

This is yet another question in the long sage of my Wildcat. Hopefully I am getting closer.
Whilst making an alignment tool I realised that the coupler on the engine I got with the boat was slightly different to the engine I got to replace it. The engine I have fitted in the boat is mounted on a largr rectangular flex plate. The origonal is a cast ally unit with the rubber bush and splines in the middle of it, the unit is mounted by 6 or 8 bolts all close together in the middle of the flywheel. Does anyone know if these having been interchanged will cause me to be having problems lining up the drive? I thought that perhaps one sat further away from the transum and that was why My splines were not going fully home. If they are interchangable there is no problem.

 

[WillyBWright]

Re: Mercruiser drive plate

The larger one is typically used on a V-8, but if it'll fit the flywheel, there should be no problem.

Newer drives use a longer splined shaft than older models. I've never measured, but a couple inches? They fit the same U-joint coupler on the drive, so sometimes you have to put an old shaft on a new drive or vice versa to fit the application. Might that be your problem?

 

[Bondo]

Re: Mercruiser drive plate

Need More Info,......
I Think you're headed for a Bigger Problem..........
It Sounds like you have, or Had a Mod.1 drive, Pre-Alpha......
And,......
It Sounds like you're installing a motor rigged for an Alpha,......
The difference in the Coupler is only the tip of the Problems.......

 

[dazid1]

Re: Mercruiser drive plate

The drive is pre alpha yes, 1972 ish I think. The engine I have just bought is a 1984, it had a flywheel housing that had the rear mounts too close together so I put the origonal flywheel housing onto the new engine but left the splined coupler on the engine, it has a trianguler flex plate that bolts to the flywheel. I am having big problems lining up the drive, it looks spot on, but am told I will never align it by sight. I was removing the coupling off the old engine to aid in the making of an alignment tool when I realised that they were different. Will I need to pull the engine again and put the origonal one back on?

 

[Bondo]

Re: Mercruiser drive plate

Will I need to pull the engine again and put the origonal one back on?

I Believe that might be So......
The Alpha style coupler is, I Think, Longer.....
The Splines are the Same though....
Atleast your donor motor is of the proper Vintage, So you Can use the old coupler......
I'm glad you found the other Issue I was thinking of......The Rear Motor Mount....