Transmission Slipping?

[TayMC197]

I have the shaft that Kyle is speaking of. It came off my 92 190. The shaft is straight and true but where the strut was are some grooves where the strut rubbed it. I later found out that it would be perfectly fine for use. I sold that boat though. I bent my strut and it was twisted on the shaft. I'm willing to part ways with it sicne I was going to turn it and the old strut into a flag holder.

[Kyle]

Originally Posted by Table Rocker

Kyle, awesome job in this thread. Above and beyond the call of duty, as you always do.

Thank you very much for the complement I really appreciate that.

[1redTA]

as far as the grooves, a welder can fill the worn spots and any machinist worth the tools he is using can get it back to specs. Atleast this was the case when I worked at Whistler Machine Works. The guy I bought my boat from needed a new shaft so they just made him another from a bigger shaft turned down.

[Scot]

Originally Posted by Table Rocker

Kyle, awesome job in this thread. Above and beyond the call of duty, as you always do.

Agreed.

The shaft sounds about the same as mine as far as the strut grooves, so maybe mine is OK too?

Never hurts to have a spare though, are the measurments the same as mine? 1 1/8" x 42" single taper.

[TayMC197]

Mine is true. I had it spun and checked. I was told no need filling the grooves, it would be just fine.

[TRBenj]

I agree that rebuilding these transmissions is unlikely to be the equivalent of rocket surgery... pretty sure the guys Ive had rebuild mine arent members of Mensa (I could be wrong!).

My point was that it seems experience counts for a lot on these things. Ive seen many smart guys f it up. The price difference between buying the components yourself and paying for a professional rebuild is not very much (I pay $600-700 for my rebuilds and Im pretty sure the OP is in the same ballpark). The guys who do this for a living have a bunch of cores and other hard parts lying around so if it turns out your pump is bad, they'll throw a good one in (usually without an extra charge) rather than charge you full retail for a new one. They also tend to know which part kits are higher quality and which small adjustments to make, as theyre usually warrantied and they dont want them coming back. Just something to think about.

Originally Posted by Kyle

Get the tranny back in and hooked up. If you have not fooled with any adjustments on the mounts then I bet you will start alignment in somewhat of a good ballpark figure. Get the mounts tightened to the stringer and tranny ready to roll. Start the boat and see if the tranny shifts correctly. After verifying correct tranny rebuild then fool with the strut.

If something freaky happened when you rebuilt the tranny and it has to be taken out again then the strut steps and pre alignment was all done for no reason and will have to be done again.

I think we disagree again here. There is no need to install the tranny before doing the first half of the alignment, as it is completely independent of powertrain location.

1. Align strut to the log
2. Align powertrain to the shaft

Both halves require you to feel for the spot where the shaft rotates freely in the bore of the strut, and align the components to that point. It is definitely a LOT easier to do the first half of the alignment with no powertrain in the boat whatsoever, if thats an option. Definitely no need to have the tranny in place either way.

Regarding repairing the shaft, that sounds like a fool's errand to me. Not sure what it would cost to repair, but I bet the difference in price between the repair and a new ARE ($380 for a 1-1/8" from SkiDIM) is less than the cost of a new prop... which is exactly what you'd be buying if the shaft breaks. Shafts can and do break- Ive seen it. Especially considering the fact that youve got the torque of a 1.5 reduction tranny twisting it, mated to a big frickin prop. Theres a reason MC went to the 1-1/8" shaft, remember.

[Scot]

Well, everybody's input is certainly helpful. Of course I am taking bits and pieces of it all and adapting it my situation.

Kyle, unfortunately nothing was ever lined up right since my stringer replacement. I trusted my local shop which was a mistake. I had them pull the motor before I did the stringers and drop it in and "align" it at the end. Took 2 hands to turn the prop. Its taken me until now to see the whole picture. So I am starting from scratch.

Here is my plan, and I will be doing a lot of research after this post so this may change, any input is welcome.

First step is to align strut to the log. My plan is to get a piece of pipe that fits into the log and centers the shaft as much as possible. I will find the strut position that centers it to the shaft as good as possible and put it there whether it requires grinding, spacers or fiberglass (epoxy). Now my shaft and strut are centered to the hull.

Next step is tranny install. Before this I plan on lifting the motor up by removing the two big locknuts on the jackscrews and taking a big wrench and some liquid wrench to the sliding eye bolts to make alignment much easier. The ones on the tranny were frozen in place and when I rock the motor right now it only rotates on the bushings, not the swivels like it should (and yes, the locknuts are loosened.)

Next step will be the standard motor/tranny to shaft alignment with feeler gauges at the coupler and adjusting jack screws and side to side. Now everything should be aligned to the center of the shaft log.

Am I thinking right here Kyle, TRBenj, or any other experts?

[Scot]

Also, I think I am going to run my current shaft this season. Its straight at least. If it vibrates a lot I will replace it. If mild grooves at the strut bearing are "normal" then so is mine.

TRBenj, as far as shops go in my town we have three. One only works on jets, one only works on v-drives but only does it as a side job, and then there is the main shop that does everything. I was quoted 1800 for a tranny rebuild by them and trust their quality of work less than half of my own. I could drive a few hours to Phoenix or San Diego and get better work, but I'd rather go it on my own.

If I didn't spend so much damn money to be an optometrist I would open a marine shop in this town!

[Kyle]

If you are starting blind on alignment then I say you have a good plan.

I dont think that it really matters who's way is better. The glass is half full either way. It doesn't matter the way you do it as long as it gets done.

I just personally would verify a good tranny rebuild first. Removing the strut and re installing it won't matter if the tranny is in or not. The strut or tranny won't be in the way either way.

I don't see it being easier or harder either way. It's work that needs to be done and it won't matter the order.

I just personally would finish fixing one problem before fixing another out of personal preference. Not because one way is right or wrong, better or worse, faster or slower.

[TRBenj]

Kyle, there are 3 problems, not 2.

1. Transmission rebuild
2. Strut to log alignment
3. Powertrain to shaft alignment

Agreed that working on #3 without verifying #1 is fixed is probably a waste, as you need to perform a powertrain alignment every time things come apart. Working on #2 is completely independent of the other things, and certainly wont need to be redone every time the tranny comes out. The fewer things in the way, the better (so Id do it now while the tranny is out) but it can certainly be done anytime.

Scot, it sounds like youve got the basic concept down. Use the old shaft for all of your strut to log alignment checks (dry fits). Once you finalize your strut mounting scheme (shims, grinding, whatever) then go ahead and bed it down in 5200... and check the alignment again with the old shaft. The strut can move around enough in the bolt holes to cause the shaft to hit the log. I'd snug up the strut hardware, check the alignment, and adjust the strut position with a BFH if necessary (it usually is) to get it perfectly centered again.

Remember that the point youre aligning to is where the shaft spins freely in the strut. There is come clearance and squish in the shaft bushing that will allow the front end of the shaft to sag under its own weight- make sure you dont align to this point.

I would not agree that grooving in the shaft at the strut bushing to be "normal". Smooth and polished, yes. But if you can catch a groove with your finger nail, its junk.