outdrive reinstallation questions. OMC Cobra 5.0 V8

Hi everyone. My father, grandfather, and I are in the processes of replacing the engine in a 1988 Bayliner Capri with a 5.0L V8 Chevy 305 with a Cobra outdrive with mechanical shift.

We got the boat with a hole in the water jacket last summer. After trying to JB weld the piece of block back onto the engine block (which only held at idle) we decided to buy new replacement block. Sorry I dont know the exact terms but it already had the pistons and valves in it, we just need to replace the upper exhaust and what not.

The engine swap went without a problem, until today. It was time to place the stern drive back on to the transom. We used the GM/OMC Alignment tool to make sure that everything was aligned before we tried to slide the drive shaft into the unit. However, we cant seem to get the outdrive to slide back onto the transom. Its almost like we are hitting something inside the boot that the gimble bearings slide into.... We tried to turn the engine manually with a breaker bar/wrench, thinking maybe we were up against the splines in the coupler but you can still slide a piece of plastic in between them. So maybe the gimble bearins are hanging up inside that boot thing.

Second problem:

We tried to place the out drive in gear by pushing up on the shift connector on the back side of the outdrive, it moves up into gear, but we cant turn the prob at all. We placed a very large screw driver in between the gimble bearings and tried to turn the shaft, but no go. Where are we hanging up? its almost like there is a pin or something stopping it from turning over. We can place the gears back into the neutral position and the prop will spin freely.

Attached are some pictures of the engine/outdrive and transom.

Thanks for any help! sorry if this post is confusing or doesn't make sense.

-Jared Bennett, Oregon

Here is a picture of the Original engine with the hole in the water jacket


This is a picture of the new block.


Transom/outdrive 1


Transom/outdrive 2

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

If it spins in neutral then you need to take off the top cover of the drive and check for damage.Jerry

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

What is the history of the outdrive? Did it turn freely when you got it? Has it been stored with oil in it? Sounds like it has seized up.
Are you able to get the alignment tool to slide freely into the engine coupler? If so, the drive should go on. That fact that it is seized is probably making it hard (impossible) for the splines to mate. It can be tough to get the u-joints to go through the bellows. It helps to warm up the rubber bellows by putting a droplight into it for a while.
Now for some parts clarifcation. The gimbal bearing is up inside the transom assembly where you inserted the alignment tool. The two things in which you stuck the large screwdriver between (when you attempted to turn the drive) are U-joints.
The gimbal bearing, u-joints , and bellows are all regular maintenance items that need attention now while you have it apart. If you dont know when they where last replaced then it's probably time, At the very least, they should be inspected, greased, etc.
Good luck

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

Yes, when we first got the boat the outdrive worked perfectly. We never tested to make sure it worked prior to starting the engine swap.

Sorry about the mixed up in language in the first post. Yes the U-joints, not gimble bearings!


The boat sat all winter inside a garage with a hole in the block. The outdrive was not drained of fluid, so this could be our problem that it is seized.

So my question is, how does one un-seize an outdrive? and if it will need to be taken to a professional boat mechanic on average what would someone pay to get it fixed?

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

Take cover off first. Then speculate. The drive can be had on e-bay from time to time. Craigs list.
After inspection get back to us.Jerry

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

With the drive in neutral, can you stick a screwdriver thru the u-joints and turn it freely?

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

BennettOZ said:

The outdrive was not drained of fluid, so this could be our problem that it is seized.

Click to expand...

No. Setting it up with NO oil could cause it to seize.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

bruceb58 said:

With the drive in neutral, can you stick a screwdriver thru the u-joints and turn it freely?

Click to expand...

No, I can manually set the gears so the prop will freely spin. thats the only thing that will spin.

marada1 said:

No. Setting it up with NO oil could cause it to seize.

Click to expand...

OK, Maybe it leaked! More investigations will tell.

jerryjerry05 said:

Take cover off first. Then speculate. The drive can be had on e-bay from time to time. Craigs list.
After inspection get back to us.Jerry

Click to expand...

I will check the outdrive some time next weekend. the boat and engine are in my Grandfathers shop about an hours drive from me. My family is heading up there this coming friday as I will be graduating from College this coming saturday. So either my dad will take a look or I will on sunday.

What should I be looking for when I take off the cover?


Thanks again everyone I will keep you all posted.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

BennettOZ said:

No, I can manually set the gears so the prop will freely spin. thats the only thing that will spin.

Click to expand...

Be aware that turning the u-joints also turns the water pump impeller so it may be near impossible to turn the drive shaft in the opposite direction that the water pump turns, especially since it has been sitting awhile.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

Check & double check the alignment. If it's not dead on you will fight & fight with that drive to get it back on. More than likely, that's the problem. OMC's are notorious for this. Been there, done that.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

sea wolf said:

Check & double check the alignment. If it's not dead on you will fight & fight with that drive to get it back on. More than likely, that's the problem. OMC's are notorious for this. Been there, done that.

Click to expand...

Thanks Seawolf.... During the week I don't have the time to work on the boat, so during the weekends I do, I will check this coming up weekend, most likely sunday because I graduate this saturday.

I just hope its something fixable.. without having to get a entire new outdrive.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

Try lifting the shift rod to engage the drive & then turn the u-joint shaft. The prop should turn, if it doesn't you have a problem.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

sea wolf said:

Try lifting the shift rod to engage the drive & then turn the u-joint shaft. The prop should turn, if it doesn't you have a problem.

Click to expand...

Yeah, already tried this! We are gonna take a look at it this weekend again, and see if we can find anything.

I will keep ya'll posted!

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

You need to figure out if there is a problem in the drive first, like sea wolf said, if you move the shift rod up and down, you should be able to shift it into gear, but you may want to have some one turn the drive shaft clockwise as you face it while you are trying to shift it, that may make it easier to see if it goes in gear.

As far as getting it on, there is a big difference between the old style bellows for the drive shaft and the new style, the new style has much more clearance inside for the ujoints. Also, did you oil the 2 o rings on the drive shaft? Make sure the splines are greased with spline grease as well.

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

BAD NEWS!!!!!!!

We took a look at the outdrive a little closer today, and we went to drain it, and water came out of the drain hole, about 1/4 of a cup probably, but no oil! So its basically toast and explains why we cant turn anything, because its seized up!

So now we are on the look out for a used Cobra outdrive! if anyone know of a place to get something for a decent price. let me know! thanks!

Jared

Re: outdrive reinstallation questions. OMC Cobra 5.0 V8

Its back on the water!

We recently finished up the boat. We had the out drive taken apart professionally and it in fact needed to be rebuilt as well. The outdrive however looked brand new and all the gears where in perfect shape. We had to however replace all the bearings and one lower unit shaft that had some rust on it.

We also have a few more things to tweak before its perfect, the gear shifting is a little stiff in the handle just a matter of linkage adjustment there though...

Oh yeah.. Our Trim indicator on the dash doesn't work know. not sure what thats about yet either.

Here are some pictures of our recent trip to the lake.. Green Peter Lake. Oregon.