MH-30 on it's Pan, and lead ingots(?)

[neildeb2]

Merry Christmas all! It's been stormy, snowy, icy, and now it's pouring rain. Not normal for the PNW this early in the winter. I feel like we're on New England...

I have a Hat 58 LRC, 1975.

My 4-71Ns have Allison MH-30 transmissions. Ever since I've owned the boat, the aft edge of the transmissions have been very close to the bottom of the fiberglass pans that lay under and surround the engines to catch oil spills, coolant spills, etc.. These pans appear to be original.

While replacing the output side oil seals I realized the port engine is actually sitting on the fiberglass "pan" under the engine. I jacked the (new in 2020) mounts up and found the tranny had worn a hole in the pan. I lowered everything, lined up the transmission output flange with the shaft coupling, and sure enough - to align it the engine has to be low enough the transmission sits on the fiberglass pan. The mounts are new, the shafts are straight, I have no vibration or runout.

Question 1: Any idea if this is normal? To raise the engine up enough that the transmission doesn't rub I'd have to change the angle of the struts and shaft log.

Question 2: Does anyone else have fiberglass pans built in under their engines?

Question 3: I removed a portion of the fiberglass pan so the transmission doesn't rub. I intended to re-glass in a lowered section of the pan. To my surprise I found like 20 large lead ingots(!). They're laying loosely in stacks under the engine. Is this common? Do others have lead under their engines?

Thanks for any insights, Merry Christmas, and stay warm!

 

[Sadey]

I can’t answer the original question but I too found about a dozen lead bars in the farthest aft port side compartment. Wish they were gold bars.

 

[Pascal]

No idea about the pans, maybe they were added

It is somewhat common to add lead to correct a list BUT it should never be loose. They are usually glassed in. Also, putting them in the engine bilge sounds like a bad idea as it will make cleaning much harder. And possibly limit the bilge capacity.

 

[dsharp]

The next time you haul out check to see if the shaft is centered in the shaft log. The original mounts will settle over time. You could always move the engine forward to raise it.

 

[zigzag930]

Neil,

No pans on my 58LRC. I use oilzorbs under them, because at the moment I have a small drip from the pump, which I have not sent for repair yet.

No lead (or gold) bars either.

In all the photos I've collected of 58LRC's in the past few years, I don't recall seeing any that had pans under the xmissions.

Jim

 

[Glory]

Is it possible the engines could go forward? That would also raise them, the space between the last strut and the prop will answer this.

 

[Captain Ralph]

I looked over a 58 LRC years ago. Should of purchaser her. Kick, kick, kick myself.
6-71s and nice glass pans under them. Looking back, think they were TD clutches.

I luved that full beam engine room.

Thru the years I have discovered factory lead in many boats. Mostly used in displacement or semi-displacement hulls, just a few bars here or there can really make a difference in a few different ways.

Moved some around a few times. Sometimes to the better.

 

[SKYCHENEY]

The pans are not OEM. They were added. As was the lead. Hatteras added lead bars to correct list but never under the engines.

 

[Captain Ralph]

The pans are not OEM. They were added. As was the lead. Hatteras added lead bars to correct list but never under the engines.

So, somebody pulled the engines up and put a pan in?
Why knot ad lead under the engines?

Anybody asked the factory on this?
Think somebody still answers the phones.

 

[SKYCHENEY]

So, somebody pulled the engines up and put a pan in?
Why knot ad lead under the engines?

Anybody asked the factory on this?
Think somebody still answers the phones.

Yes, apparently so.

Lead can be added but it would be in the engine sump area unless you added a pan above that area fist.

 

[rsmith]

The only reason I’ve heard lead added is to correct list. If your going to do that you want it to be as far away from the center of roll as possible certainly not under the engines. People get way too spastic over this alignment thing. First with a 2/1 reduction gear the shafts are spinning mostly 500-1000 rpm ain’t all that fast. Second and it’s really obvious on a Ochit yacht but these hulls no matter how well built flex and move underway. Same with the shafts. When I went to one piece shafts 13’”9 x2” I was surprised how much the shaft bowed when we pulled it out of my truck and were carrying it. Thirdly for those of you who haven’t given your admiral’s early retirement can attest everything sags over time. Given the weight of the shafts and flex of the hull when you break the coupling the shaft can drop 3/8” or more. If you keep adjusting the engine mounts down to compensate sooner or later you will hit rock bottom. And as the exspurts will tell you all this is subject to change when the boat is in the water.

 

[madhatter1]

On our 34 with Cummins installed 24 years ago the isolation mounts collapsed over the years. Shafts sat low in the logs but no vibration ever. Also a few years back I pulled up engine hatch to check something while we were running in very choppy water. Both engines were dancing around. I was shocked but learned it’s normal. Remember, fiberglass is plastic after all.

 

[neildeb2]

Thanks all, for your input. I went ahead and removed a portion of the pan underneath the transmission, and then refiberglassed under it. Now I have about an inch of room below the transmission. I also secured the lead weights as best I could. Yes, I could move the engine forward and that would raise it up off the pan even more. Until I have the boat out of the water I don't know if that's possible due to spacing between the prop and the first strut, as you mentioned.. It would take a pretty good come along to slide everything forward. Then I would also have to drill new mounting holes. As it is, I can now move the engine up or down to mate it with the prop shaft coupling.