Engine/Drive shaft alignment

[Justin_C]

So if you've seen any of my other posts, I'm sure you can put together, I have a lemon. So the most recent problem is that the transmission blew (probably clutch plates or oil pump). What I'm thinking though is that this has something (or everything) to do with last year's problem when the oil pan went through a bolt on a tracking fin. I'm thinking that the engine alignment isn't right, after all, a boat with under 400 hours shouldn't have to have the transmission rebuilt. The thing is that the people at the shop, when they put the engine back in after the oil pan fiasco assure me that things were aligned right at the coupling. The engine still sits so low that the brass clamp on the hose coming out of the oil pan is digging into the hull. Any ideas as to how to realign things right so that maybe we might be able to get out of this mess before I end up on the streets?

 

Thanks

 

P.S.

Boat: '97 MB Sports Boss LS200

Engine/Transmission: PCM GT-40 EFI 1:1 (Ford 351)

 

 

[Justin_C]

Here's where the oil pan sits and where the right angle is digging into the hull

 

[Justin_C]

And what that right angle looks like when the engine is out. It's worn that bolt right down.

 

[BruceEmery]

If the engine alignment is off there would be a noticeable vibration. Does it seem different from before the engine was removed?

[Justin_C]

We bought the boat last year second hand. Can only assume it was this way when we bought it and just didn't notice. It runs fine, no vibration, which is why I find it so odd that the engine is now sitting so low. My thoughts are the the strut is bent or the strut bushing is worn funny causing the drive shaft to come through the boat at a different angle?

 

[Jody_Seal]

Checking alignment and proper thru hull positioning of the propeller shaft is quite easy. Loosen the band clamps on the shaft log seal hose where it attaches to the the shaft log, Then pull the seal assy forward on the shaft exposing the shaft log barb. If the shaft is not running through the log right square in the middle of log then their is some sort of issue!

[Justin_C]

Thanks, I'll have a look once things are back in. When you say that though, we noticed this spring that the drive shaft doesn't go right square through the middle of the packing nut, would that have anything to do with it?

 

[A_B]

Jody, could they move the engine forward an inch or so to elevate higher on mounts? I don't know if the shaft can be pushed forward to meet it, but it might be one way to creat some space.

[Jody_Seal]

Dont know if they could move the motor forward in that boat, if they could it would require a new shaft. If the shaft is not going through the log correctly and naturally wants to run low on the bottom of the log/insert I would be more inclined to shim or machine the strut about a 1/4 of a degree to get the front of the motor up and make sure the shaft is running true through the middle of the log/insert. only looking for about a half to three quarters of an inch for clearance under the oil pan. Moving the engine forward could upset the CG of the boat, just to many unknowns.

[Justin_C]

I am just baffled as to how the engine is sitting so low now, yet it's apparently still in line

[Waternut]

There is no way the engine is aligned if that brass piece has dug into the hull. It MAY have been aligned prior to that piece digging into the hull but not anymore since the weight of the engine in a shop can't dig into the hull like that. Just because you don't have any vibrations, doesn't mean it's not aligned. You should be able to move the prop with ease using one finger certainly when the strut bearings are wet.

 

Here is an excellent video on how to check alignment.

[Justin_C]

My thoughts exactly! I've seen this video. Kind of tempted to send it to the mechanic who is working on it who just keeps telling me that it must be the previous owners who must have replaced those bolts and what not cause he insists that it is in alignment...

[Waternut]

It really takes quite a bit of time to PROPERLY align an engine that has been pulled out. Unless you're going to shop that is notorious for excellent work, I'm guessing they subscribe to the mentally of, "pull the mounts with the engine and you won't have to realign anything" or "if it bolts up without binding, it's aligned".

 

Feeler gauges are cheap. Go get some and start tinkering. My alignment was actually off for about 2 years before I realized it and the couplers had worn themselves into a happy spot. So it took me many hours and a couple days to figure out exactly how the couplers had to be aligned with each other and with everything else.

[Justin_C]

he says he uses feeler gauges and he deals with a couple other ski boats as well that I'm sure he's had to realign. I just don't know whether to trust him, or my gut feeling and everyone saying that it's not aligned

 

[Justin_C]

thanks for your advice though! I am certainly going to challenge him on this and make sure it's aligned properly

[Waternut]

One or more of a few things had to happen...

 

1. He aligned it using the proper method and just missed the fact that the engine was digging into the hull. If this is the case, the engine is no longer aligned since the engine has clearly dropped down as it dug into the hull.

 

2. He winged it, neglected to properly align it, and just eye balled it. If this is the case, the engine isn't aligned and likely never was.

 

3. He purposely chopped into your hull/engine hardware to get the engine properly aligned. If this is the case, the engine may still be aligned properly but yikes...

 

4. He aligned it based on where the driveshaft sits naturally due to gravity instead of getting it centered in the shaft log. If this is the case, the engine is way lower than it's supposed to be and it's not aligned because the shaft is tweaked in the strut.

 

I would talk to the guys about it and see if they'll make it right. I personally wouldn't be rude at first. If they aren't willing to help you out, then you can get rude but I'd try to be civil first.

[colo_skier]

My first thought to this is that the brass colored part that is worn is the wrong coupling for the oil drain. In the first picture the bottom of the oil pan seems to be just clearing the nut on the hull that I assume is a tracking fin. If you had a shorter coupling then it wouldn't gouge the hull. The alignment is really easy to verify via guages. Maybe the strut support(? don't know the correct term) on the outside is 2 short. Either way something is not right. Maybe the previous owners did an engine swap and the pan is to deep?

[Justin_C]

That picture that looks like the oil pan is just clearing, isn't. It's actually up through the oil pan. It's a picture from last year's issues that clearly weren't fixed right. The oil pan is original as we found out when we were looking into how to go about fixing the hole in it last year and the engine is original as we have all of the paperwork and everything from when it was new. Like you suggest though, I have wondered about the strut. Thanks for the help!

[Justin_C]

As for waternut, thanks for all of the suggestions and advice. Thoughts 1,3 and 4, or a combination of all of them I think is probably what has happened. Great thoughts, I really appreciate it!

[BraceMaker]

@Justin_c - I think you have to realize that the shaft's natural alignment is dictated by the strut.

 

If your strut is bent or not sitting flush for some odd reason the angle of the shaft into the boat will be low - dictating a low position of the engine/transmission to reach alignment.

 

Really no way forwards other than to pull the prop - split the coupling, move it back far enough to separate the coupling, and check out the "up/down" play - center that and see if it aligns with the coupling, then check the feeler gauge gap to see how aligned it is.

 

If that is good and it isn't immediately apparent that the trans couplings axis is too low (in which case I would raise the engine and blame alignment) then you have to delve further.

 

For instance - alignment appears perfect, but shaft seems low - verify that the shaft is going through the log fairly centrally, if it is low I would atleast try loosening the strut , shimming under the rear of it to see if you can get the shaft to go through centrally, or even a bit high. And if so you should be able to then raise the engine.

 

 

 

In a worst case scenario you might need to shim the strut, grind out the log, glass in a few layers to elevate the log and then reglass the log into place. which would both raise the engine, raise the log and angle the strut... Seems like quite a task.

[Waternut]

I agree with @Bracemaker that you may need to shim your strut if it doesn't work out otherwise. If you do need to shim the back of the strut a little bit to get the engine off the hull, be very careful of your prop to rudder clearance. There are a lot of little angles and adjustments that can go a long way in the wrong direction. It's all a big puzzle and a bit of a dark art when things start restricting which ways you can move. Typically they can be compensated for with something else but you have to pay attention to them.

[Justin_C]

Thanks guys. Now when you talk about where it goes through the log, do you mean where it goes through at the packing nut or farther down the shaft where it actually goes out through the hull? And if we have to shim, what would we use? I'm assuming you would put some sort of caulking around it after...?

[BraceMaker]

If its me - I pull the nut and look at the log - from below the boat should give you some idea, but it might look like it is entering high if it is exiting into the boat low.

 

I'd use stainless auto shim stock, once I got the thickness I wanted I would caulk it to the hull, then run a bead of 3M around the strut and install to loose torque, then retorque the nuts after it set up.

 

Waternut nailed it the whole thing is multi-faceted. You may even have enough play in the holes through the engine/trans mounts to slide the whole thing forwards if you had strut clearance issues with the rudder. My boat doesn't come that close.

[Jody_Seal]

Shimmed many a strut while in the engineering Dept at Correct Craft. Never used shim stock but utilized 3/8" SS flat washers and sealant..... However that was for temporary testing! for permanent application the preference is to have the strut base machined on a milling machine to accomplish the needed strut angle. looking to get a half a degree or less will require minimal material removal and will not compromise the structural integrity of the part.

[BraceMaker]

Interesting. Did you find that to be a difficult set up?

 

That's where I'd enlist an antique metal shaper - I hate trying to mill a flat surface.

[Jody_Seal]

fit it up in a Bridgeport and fly cut It ! To achieve what Justin needs with his boat is probably no more then an experienced Tech to properly adjust the alignment.

 

Some may remember the bump on the bottom of the early TSC hull's under the oil pan. Reason was for relief clearance of the oil drain kit. Their was one maybe two years an oil drain kit was unavailable until we put the relief in the molds. even after that we were adjusting a few struts in the Bridgeport to achieve clearance under the pan.

[BraceMaker]

A Bridgeport!

 

My knee mill is an old baby gorton - with a fixed head, means lots of angle plates and such for that sorta jazz.

[JC McCavit]

@Jody_Seal - It's very nice of you to share your expertise on this forum with us Ballers.