How to move a 6CTA for alignment?

LMBoat

Well-Known Member
Oct 4, 2006
748
Ft Lauderdale
Boat Info
1999 450 EB
Engines
Cummins 6CTA's
Hi All,

I need some help. I’m trying to finish a prop shaft/coupler alignment on my boat (’99 450EB w/ Cummins 6CTA’s, and they are v-drives).

I’ve determined that the front end (fan belt end) of the strb engine needs to move inboard, probably just 1/8” or so. I have all the engine mount bolts loose, but can’t figure out how to scoootch over a 2,000 lbs engine. The best Idea I have at the moment is to use a “come along” device attached to the port engine to pull the strb over. But I’m afraid that I will pull the port engine out of alignment that way.

I know several people on the form have dealt with alignment issues. What is the best way to move the strb engine? Ideas?

Thanks, as always.

Larry
 
I’m sure there are experienced on here that will eventually post. But in case not I only moved one of my engines. Had to move it outward, not inward. I put a scissors jack against the other engines stringer and cut a 2x4 to the right length to contact the engine. Then I just cranked the jack until it moved as far as I needed it to. So, I had considered what if I overshoot and have to bring it back. My plan was to clamp a big c-clamp to the same stringer (with 1x4s to protect the stringer from the clamp and to spread the force) and then attach a come along to the clamp and to the engine. Have no idea if a good or bad idea because I didn’t overshoot.
 
Yes I can probably help a bit.
Porta-Power with the jaws attachment. Harbor Freight has a cheap version that will work just fine. Put the jaws between the mount bracket and stringer as close as possible to the top of the stringer. Move only the engine end furthest from the coupler for coupler alignment. The engine end at the coupler is moved only to center the shaft in the log.
As a hint when you move the engine the motor mount will flex with it so move just a bit and tap on the top nut of the mount so it will shift also rather than flex. Itty bitty movements only.
 
Thanks for the comments, and I followed the advice (TT, I've read all your info on alignment. Great stuff, thanks). I went to the boat yesterday after a stop at Harbor Freight. I bought a come-along and some c-clamps for less than $40. I put the big c-clamp w/ a 2x4 on the inboard port stringer, a smaller c-clamp on the strb inboard engine mount, connected the come-along and racketed away. I could see the engine move. I used a 5 lbs sledge to scoot the mounts over. I could see that the things were moving. I checked coupler clearance, did some more, etc. after about 4 tweaks, I could not get the engine to move any more. It's not perfect, better than it was, and good enough for now.

My issue is engine mounts. The ones under the SW pump are rusty and have limited adjustment. They need to be replaced. And if I'm changing those 2, why not change all? This will be a project for the future, but if anyone has experience on doing this, please share. Local mechanic wants $4K per engine to do this.

Thanks for the comments & advice.

Larry
 
Thanks for the comments, and I followed the advice (TT, I've read all your info on alignment. Great stuff, thanks). I went to the boat yesterday after a stop at Harbor Freight. I bought a come-along and some c-clamps for less than $40. I put the big c-clamp w/ a 2x4 on the inboard port stringer, a smaller c-clamp on the strb inboard engine mount, connected the come-along and racketed away. I could see the engine move. I used a 5 lbs sledge to scoot the mounts over. I could see that the things were moving. I checked coupler clearance, did some more, etc. after about 4 tweaks, I could not get the engine to move any more. It's not perfect, better than it was, and good enough for now.

My issue is engine mounts. The ones under the SW pump are rusty and have limited adjustment. They need to be replaced. And if I'm changing those 2, why not change all? This will be a project for the future, but if anyone has experience on doing this, please share. Local mechanic wants $4K per engine to do this.

Thanks for the comments & advice.

Larry
Get that mount soaked down with Corrosion X and after a couple of days and wire brushing you should be able to get the threads cleaned up and the nuts and washers able to move the full thread height.
 

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