New Engine Alignment Problems

[dougd59]

I have replaced the 1991 4.3L in my OMC sterndive. The replacement block came out of a 1995 S-10 truck. All other parts came off of the original marine engine. I of course, had to add an electric fuel pump for the carb, but other than that, everything is stock.
I am having a pretty serious alignment issue with the engine. It seems as though the rear engine mounts aren't allowing the coupler to drop low enough to even begin aligning. It is at least 3/16" too high. The rear mounts are sitting properly.
Is there a chance that something changed in these two blocks, as far as centerline position of the crank? I'm stumped. (Yes, I have the A -tool)

 

[Bt Doctur]

Re: New Engine Alignment Problems

4.3`s are all the same.Have you tried raising the front mounts

 

[dougd59]

Re: New Engine Alignment Problems

Yes, it gets the coupler a little closer, but won't allow for the tool to fully seat. It seems like the rear mounts are just too high.
I did replace the gimbal bearing too, and I saw on one thread that someone recommended "aligning" the gimbal bearing with the tool before trying to insert it into the coupler. I'm new to this, but I've never heard of that.

 

[Bt Doctur]

Re: New Engine Alignment Problems

When you drive the gimbal bearing in ,it may not be aligned with the coupler. It "gimbals" (can be moved in any direction within the tolerance ring) so you tap the end of the alignment bar to move it slightly up,down,left,right .Then try adjusting the mounts for a perfect fit.

 

[dougd59]

Re: New Engine Alignment Problems

Doc,
Thanks for the info - it worked. I think when my son can come by and help me adjust the front while I try the alignment tool, we can get it correct. At least the tool starts to go in now. THANKS!