problem with 3.0 OMC Stern Drive

[citation]

hey everybody. i'm new to the site and new to the boating world. three weeks ago my brother purchased a 1983 Thundercraft Citation from my uncle and he appointed me engineer. it has a 3.0 OMC stern drive as noted in the topic. here's the problem; whenever you lower the transom (i hope that's the correct word), there's a lot of grinding sounds coming from between the motor and the stern drive. when it's raised, the engine runs and revs fine. we've taken the boat out a few times with no problems untill this past tuesday. i was not there so i don't know exactly what happened.

i was doing some research online yesterday (mainly here) and found a lot of information about cobra drives and the cable problems but from my understanding, this stern unit is not a cobra. i'm very mechanically inclined as i am an automotive mechanic in my professional life, but boats are new to me. i just want to get a few ideas before i get elbows deep in this.



thank in advance

 

[PINESOL]

Re: problem with 3.0 OMC Stern Drive

welcome to iboats ....
what you have been appointed is considered a stringer drive , it was before the cobra.. if you search under stringer tilt problems you will find all you need to know ...

 

[citation]

Re: problem with 3.0 OMC Stern Drive

thanks for the suggestion! searching now.

 

[Maclin]

Re: problem with 3.0 OMC Stern Drive

On those you cannot have the engine running with the drive tilted very much at all or the ball gears take a beating. Lots of threads and postings about that.

 

[chiefalen]

Re: problem with 3.0 OMC Stern Drive

Welcome. So you have a stringer, I'm chuckling to myself.

Your gonna love her or hate her when your done fixing her, but you will get to know her.

You have to get a manual. Factory original the best, seloc second best is what i have. Wish I took the time and extra few bucks to get the factory. What you need is up to 1985 stendrive. Claymore just toilet paper.

Heres a old post let us know how you made out.

http://forums.iboats.com/showthread.php?p=1740770#post1740770

 

[citation]

Re: problem with 3.0 OMC Stern Drive

i checked out a lot of stuff on the tilt problems but i honestly do not believe this is a tilt problem, unless i'm not understanding the problem correctly.

i must not of been very clear in my first post. the lower unit moves up and down just fine. when the lower unit is all the way down, there is a bunch of grinding sounds coming from it. they are not coming from the engine. i asked my brother a few more questions last night and good some more information.

he said he was in gear and moving forward at a steady pace, about to plane, when the noise started and the boat stopped moving. i've told him to order a shop manual. i'm also trying to get ahold of my uncle as every bolt head on the lower unit is missing it's paint, so it's obviously been taken apart before.

 

[QC]

Re: problem with 3.0 OMC Stern Drive

Sounds like the ball gears are completely worn or wearing all the way off. When you raise it I could imagine that they stop making contact . . . Tilt up and look for these round gear things. I bet things will be clearer after that . . .

 

[citation]

Re: problem with 3.0 OMC Stern Drive

Sounds like the ball gears are completely worn or wearing all the way off. When you raise it I could imagine that they stop making contact . . . Tilt up and look for these round gear things. I bet things will be clearer after that . . .

thanks for the tip! i was hoping someone could point me in some direction. i probably won't get to it until sunday, but i'll try to keep people posted. thanks!!

 

[chiefalen]

Re: problem with 3.0 OMC Stern Drive

If it was me having to replace the ball gear, you will have to take off the drive to do it, i would also

1- Install a new impeller.

2- Check the splines on the impeller shaft. You have to take it out anyway.
Maybe stripped out.

3- Check all the gears.

Depends if your uncle ever rebuilt the lower and upper unit. But I would bet, you have water in the upper, maybe the lower and maybe in the intermediate.

While your at it, check the clutch housing.

 

[lionhearted_xx]

Re: problem with 3.0 OMC Stern Drive

Hello, I have a 1983 thundercraft with a 400 series omc out drive and a month ago mine made a loud pop in drive, the motor would not turn over, so I bought a manual and took the lower unit off and there is a plate on top of the upper unit that has a worm gear for the steering, it was in peices and them peices fell down into my upper unit and tore the gears up in it. The upper unit was my main problem and finding a good used one is really hard and they are not cheap to rebuild. If you do find a used one, make sure you check the stering out. the only upper unit i could find wast the right gear ratio and worked good other than my steering was backwards (easy fix) lol but now I have other issues good luck and I'm sure we will chat sometime

 

[citation]

Re: problem with 3.0 OMC Stern Drive

i just want to start off by thanking everybody for the suggestions and tips.

i went over to my brother's house today and took a peek under the skirt of the sterndrive. Sure enough the ball gears lost their... uh, balls. completely worn down. i took pix and will try to get them on a computer soon if anybody is interested. we ordered a manual for it and should be here thursday. looks like i'm going to get to know a sterndrive better than i ever wanted to.

chiefalen,

i really don't know what all my uncle has done to this boat. i know what he says he's done, but that's not always correct. i checked the fluid levels in all three areas a couple weeks ago and all seemed good. he told me that he had just changed out the oil in it but i wasnt sure as he also said he changed the plugs in the motor, but i swear i pulled out 10+ year plugs.



i'm going to try to get cracking on this asap as we just bought the boat and want to get as much use out of it as we can. i saw there are ball gear kits available threw links from this site. what all is suggested that you replace when doing these? i.e. sealing kits, bolt kits, gaskets, etc etc.




thanks again everybody.. great site. a week ago i didn't know what a ball gear was.

 

[chiefalen]

Re: problem with 3.0 OMC Stern Drive

You have to remove the drive anyway to do the ball gears no way around that.

Look on ebay for the kit around 125-150 for the whole kit. You will have to do both.

You will have to take off the cables inside the boat to get the cable out of the outdrive. Be very very careful with the cables. Hard to get and expensive.

I would do a leak test before I take it apart, with the oil in it. That way you'll know if you have to buy a seal kit for the upper,lower or intermediate housings.

When you have it apart or run into a problem post and there's alot of people here who will help.