Growl/vibration in the floor
 

so my old alpha 1 died a horrible death, ran it low on oil and broke everthing in the upper. I bought a brand new SEI entire drive and bolted it on, but not before having the local marina replace my Gimble bearing. I did not ask if they aligned it but I was assuming that would be part of a gimble install. Anyway, with the new drive and new gimble, I have a hell of a vibration or growl in the floor that gets worse with higher RPM. I know the SEI drives make a little whine, but this is a vibration. I am planning on pulling the drive this weekend, and will try an alignment, but is this even a symptom of a misaligned drive? I dont' know why the alignment would have changed from the old drive, and it never made this vibration......... ideas? Hub? Outdrive? Alignment?
THanks
tom

anyone?

Use good synthetic oil in that SEI and it'll give you no trouble. I changed mine at 5 hrs and again at ten, and the whine went away. Just gotta get those gears ran in. I had a vibration in my floor too, and it ended up being the drive couplers. Lost both in one outing. PITA, but I'd rather do both at the same time instead of having the other fail about halfway in to the next season.

When I called SEI they told me they would be suspicious of the coupler too. They said that old drive coming apart like it did may have been hard on the coupler. I stuck my hand down on the driveshaft right out of the coupler while the engine was idling and it just had a very slight bump up and down if any, but might be a different story once some power is applied. I obviously have to pull the engine to replace the coupler right? I'm sure its the original thats on there now. I guess I just run it till it goes out, but I HATE getting towed back home! Especially on the river! its tough towing in the current. I guess i'll just take it easy this weekend, then Sunday I'll pull the drive, have the Marina check the alignment, or buy an alignment tool on Ebay for $60, then go for the coupler.

The only bad thing about waiting for the coupler letting go is the mess it creates and the potential for additional damage, not to mention that you'll be nowhere near where you need to be when that thing gives up. Yes, you'll have to pull the motor most likely to get to it.

the gimble bearing will cause a vibration in the floor if they installed it wrong and damaged it, when you pull the drive grab the gimble and feel it for smoothness, there should be no nochiness at all, and check the u-joints for binding, its very rare for a coupler to cause a vibration, they just go away, but if they installed a new input shaft in an old coupler, that could create a problem.

I agree that it could be the gimbal bearing or u-joints too, but, assuming it was installed correctly, and knowing that "complete" SEI drives are complete from input shaft to output shaft, my assumption was that the alignment may not have been done, which would put the coupler in a bad way and cause vibration/premature failure, and also, the failure of the previous drive could have seriously tweaked the coupler and caused it to begin the process of self-destruction. Any of which would cause the vibration he mentioned. I basically assumed that all the new parts are still intact. Both of my drive couplers failed within roughly three hours of each other. One was giving a slight vibration like a tire out of balance for about two days of boating. When it was ready to go, it got bad quickly and failed. The other one started vibrating as we were making the slow trek back 20 miles to the dock at low throttle and began the same vibration deal. I found a ramp about halfway back, tied off, and called some friends to come and get me. The second coupler puked while I was loading back on the trailer. If his other drive gave up voilently, or the alignment wasn't done or done right, my money would be on the coupler being the problem.

PS----I would definitely check all the things hoozurdaddy said to before I pulled my motor though. It would be a real pain to do all that work and it be one of your "new" parts that is the problem...

I did check the gimble after they installed it and it spun smooth as silk. An alignment problem won't cause a vibration? If not, it's got to be the drive or the coupler. I will pull it and see what I can find. I think I'll buy an alignment tool so I can feel it for myself. I hate trusting the shop to do anything on any of my vehilcles. What about greasing the coupler? I doubt it has ever been greased before. I just had the engine out 2 years ago and replaced it with a 383. Guess I should have changed the coupler then huh! Its not really that bad pulling the engines on these things, but I'd like to be sure it was the coupler before I do.......
Thanks for the advice guys.... If I don't figure it out, I'm going to run it wide open til something gives!

Yep, alignment alone can cause the vibration, and wear out your splines on your new input shaft, and kill your drive coupler, and kill your new gimbal bearing, etc, etc. Sucks, but thats the deal. You could use your old input shaft for an alignment tool, but it won't be as easy as using one with no splines. They work like more of a go/no go fit.

Thanks
Just ordered an alignment tool off ebay. i have actually used an old input shaft before for an alignment tool, but didn't this time because I assumed the shop did when they put in the gimble. You know what ASSUME stands for though! Well, I think I'll just stay near the marina this weekend and pull it Sunday or early next week. Maybe I'll get lucky and an alignment will be all it needs.
Thanks!

when you pull the drive, take a flash light and look at the coupler splines, they should not have sharp edges on the splines, they should look like the ones on the input shaft, If they come to a sharp point, change the coupler NOW or it will leave you in a bad place. If you purchase a tool, it should glide in with little effort and turn the same, use a good high pressure spline grease when you go back together. Good Luck

Yup! Couldn't agree more.

OK guys. I got my alignment tool and pulled my outdrive. The alignment tool went right in and turned fairly easy. Not with 2 fingers or anything but if I wrapped my whole hand around the knurled end i could definatly turn it without much effort. I looked at the splines and they are perfect, not sharp or worn at all. I bumped the engine and it seemed to line up about the same, then I pulled my coil wire and had a buddy crank on the engine with the alignment tool still installed, and it did wobble a little. I had the marinas mechanic look while I cranked it too, and he wasn't too worried about the wobble?? The owner of the marina said maybe the coupler/flywheel bolts were loose? Not sure about that without pulling the motor, but I do know that the gimble bearing felt perfect, the u-joints look and feel perfect, the upper gears in the outdrive look like new with the hint of a wear pattern starting very uniformly on the gears, and the gear oil was right at the top plug where it should be. I put the outdrive back on and drove it all weekend. I ran it several times wide open and it actually seems to smooth out at higher RPMs, but under a load especially with a full boat load of people and the trim all the way down, it definately has a vibration. Maybe I'm just paranoid, and I think it has gotten a bit quieter as the drive has broken in, but I'm telling you, there is something not quite right! I should try to see if the Marina will lend me an entire outdrive to see if it is the drive or not. Doubt they will though..........

Any wobble in that coupler is bad news. My moneys still on that being the culprit.

I've been thinking though, and maybe everybody's over-thinking this, including me. Have you tried a simple prop swap? Maybe you've got a bad prop.

prop swap----exactly----process of elimination from simple to more involved----good point. takes only a few minutes and you will know right away if it feels better----it also seems the age of the coupler was never told----you mentioned that the engine was swapped a few years ago but same coupler used----which would be no problem as long as it was in good shape and not getting dry-rotted or fatigued-----i just blew my coupler last saturday and although i have oinly owned the boat a very short time i bought it from the original owner who was very meticulous about keeping up with this checkmate----however, and im not sure, the way mine blew instantly when i snagged on something led me to believe it was either original (22 yrs old)---or at least old and fatigued----either way a new one from mercruiser is on the way and i hope to be putting it in on thursday---i recommend doing the same and buying an OEM coupler as ive gotten feedback that aftermarket ones may not be as sturdy-----good luck with it.

a prop swap is a good idea, but there should be no woble it the coupler, any woble there goes right to the gimble and then to the u-joints, and will cause your vibration, when you cranked the engine over with the bar in place, it should have been straight as an arrow, my guess is coupler.

I have tried the prop swap yes, not the problem. I sure thought that wobble looked bad as well. I know the coupler is mostly rubber so I thought maybe (especially after the marina mechanic blew that off) that was acceptable. As far as the age of the coupler, the boat is an 84 and I have no reason to think it has ever been replaced. I did replace the motor 2 years ago, but I put the original coupler back on. Not sure why this vibration just started this year with the new outdrive, but blowing the old outdrive the way I did certainly could have driven the coupler over the edge. Hell, it only takes an hour to pull the motor on this thing once I find a picker........last time my bro-in-law who flies our local copper chopper, let me pull into the police hangar and use the electric chain hoist they use for pulling chopper rotors and blades which worked great, but he was a little paranoid about his superiors catching on so i'm a little hesitant to ask him again. If I get the drive pulled and unbolt the motor mounts, wire harness, and transom water hose, i could be in and out of there in an hour easy...... what the hell, I'll ask him. Thanks guys!

I had a freind who bought a new SEI drive, and he said it growled for the first twenty hours or so, then it was fine after that. I believe these are actually built overseas, and I'm sure the tolerances aren't as good as Merc's. I haven't heard of one blowing though. I guess they just have to break in.

my buddy jeff and i did my coupler job on thursday in only a couple of hours as well---not a bad job at all---i was able to get a brand new mercruiser coupler out of nj on ebay for 209 bucks plus shipping-----i thought that was a pretty good deal---and it was here in a few days-----hoping to put it out on the water today and run the boat----lets hope no vibrations or other problems. let us know how you make out once that engine coupler is replaced in your boat k???