91 Conbrio Drive Train

[No Paddle]

We are happy new owners of a 91 Conbrio.

Second day out and we run into a patch of rocks and it takes out the prop, drive shaft, strut, and rudder. Fortunately everything else looks ok and after replacing said parts the boat will be like new again.

Thanks to this forum I have found where to go to get the parts, (let me just say that Richard at Skidim was great) have the confidence to do it myself, and now in the process of taking out the old parts.

So far so good except for a few snags.




Am I going to need to take out the gas tank to replace the rudder assembly? It is tight quarters but I think I can get back in there. Is there something that I am missing so that I should just plan on taking out the fuel tank now rather than wasting my time trying to reach in such a small place?


How in the heck do I get the bracket off the drive shaft that connects to the transmission? So far I have removed the shaft from the transmission, removed the bolt that connects to the shaft inside that gold looking bracket and created this ingenious way to get the bracket off the shaft by taking longer bolts and attaching the shaft back to the transmission only this time I placed a bolt between the drive shaft and the transmission so that when tightening the shaft bracket onto the transmission it would force the bracket off (see picture). Any way, long story short, after lots of wrenching and striped threads on the longer bolts the bracket did not budge an inch (not even a millimeter for that matter) and is still locked onto the drive shaft. Is there something that I am supposed to do with that little notch on the side of the drive shaft? Does the bracket twist off? I am at a loss.

Any help would be appreciated.

Thanks,

[DKJBama92Mariah]

For the getting the shaft loose from the coupler (the gold thing) you may have to take a multifaceted approach. Im assuming you got a new coupler too b/c this one will probably be destroyed by the time you're through with it. You'll have to combine the bolt trick you've already tried with two other things. First, you can apply heat to the coupler with a blow torch. The heat will make it expand and help it slip off the shaft. If you still cant get it off; still using the bolt trick, heat it again, and then beat the hell out of it with a hammer. Thats what it took to get mine off. One other thing, if you didnt notice it, there is a nut on the end of the shaft that secures the coupler. I was just assuming that you had already taken this off.

As far as the rudder is concerned, it is a bitch. You probably wont be able to change it without moving the gas tank because you need room to work to get the tiller arm off the rudder shaft. NOTE, you have to completely remove the clamping bolt from the tiller arm, not just loosen it, to get it to come off the rudder shaft I couldnt get my tank all the way out. I kinda had to just rig something up. I siphoned all the gas i could get out of the tank (dont do this by mouth, and dont ask me how i know.). I unbolted the tank and wrapped ropes around each end. Pulling the ropes over the side of the boat lifts the tank about 12" and i tied them off to the trailer.

For the strut, i have one piece of advice i can share from experience. Make for sure that the strut is lined up with the stuffing box before you crank down on the bolts. The 1st time, i just mounted mine and when i went to put the shaft in the next day, the shaft was waaayy out of line. I ended up remounting. I put the shaft through the stut and through the stuffing box before i cranked down on the bolts and it lined up perfectly.

Good luck and keep us posted. Fire away with any questions if you run into any snags along the way.

Cheers,
DKJ

[DKJBama92Mariah]

Just looked at your pic and i have one more comment. Those bolts you are using to break the coupler loose from the shaft suck. They look like $0.10 pieces from a hardware store. Go to lowe's or home depot and get some grade 5 or 8 fine thread bolts. They wont break like these cheapos did and the fine threads will give you more clamping power than coarse threads. They shouldnt cost you more than a couple bucks.

[No Paddle]

I will invest in a torch and try the heat approach tonight with new screws. Perhaps a new rubber mallet is in my future as well. Hopefully my efforts will not damage the coupler since I will need to reuse it with my new OEM replacement shaft. I will keep you posted.

If the tiller arm is the only thing that I need to worry about I may just try to prop the plastic tank up a bit to give me the space I need. Although your comments make me think that I will end up taking it out anyway.

Great info on the strut I will follow your wise counsel when installing the replacement.

[No Paddle]

Just to confirm, do I need to do anything with the notch on the side of the drive shaft coupler?

[DKJBama92Mariah]

I hate to tell you this, but you will likely destroy the coupler trying to get it off the shaft; I know I did. Where did you get the shaft from? Most shafts come with a new coupler. I ordered mine direct from skier's choice and it did; also, the ARE shafts from discount inboard marine come with a coupler. The coupler is made of brass, bronze, or nibral; all of which are pretty soft. If your intention is to reuse the coupler, DO NOT USE A HAMMER, it will destroy it. Any deflection of the face of the coupler will make an attempt at aligning the drivetrain futile. I would just spring for a new coupler since you've already spent so much on the rest of the drivetrain. I think they are only about 30 bucks.

Im just taking a guess at the "notch" you are referring to. There is a notch on the inside of the hole in coupler. There is also a notch in the shaft. There is a hardened steel "key" that looks like a 1/4" x 1/4" peg that fits in these two notches when you put the coupler on. This key keeps the shaft from spinning inside the coupler. This key is identical to the one used on the prop. There isnt much you can do to the key when removing the coupler. I tried to pound it out when i was breaking mine loose and i only succeeded in bending a perfectly good centerpunch.

One blatantly obvious thing that i neglected to mention. A good dose of pentrating lubricant (WD40) could never hurt. I've found that "liquid wrench" is about the best. Just make sure you clean up before going crazy with a blow torch, we dont want your boat turning into the 4th of July.

Cheers,
DKJ

[Salty87]

i've had to do some drive shaft work lately. i put the shaft too far into the coupler when i was installing it....they don't come apart easily, even in the living room! i put the coupler on just playing around to see what the fit was like and had to wrestle it all apart.

what i did, might not work for you....i made a slide hammer out of the shaft and prop nut. i had some 10 lb weights, uh huh...dumbell weights. it fit over the shaft and not over the prop nut. put the weight on the shaft, tighten the prop nut a bit, and start sliding away. you definitely need to secure the coupler and not with the tranny. i wedged a thick piece of rubber between the coupler and the hull so it wouldn't pull back any further.

good luck

[No Paddle]

Went to the store today and picked up about 25.00 worth of new parts and tools. Bolts, Torch, can of WD-40 (no Liquid Wrench) at Loews.

I am happy to report that some WD-40 with some replacement Grade 8 bolts did the trick. I am surprised at the little effort I needed to use after a few squirts of WD-40. The coupler appears to be in great shape since I did not need to do any hammering whatsoever. I was already to spend all night working on the project but it came right off.

Thanks again for your tips. I am sure that it would have never come off without your advice.

I am going to tackle the rudder in the next couple of days. Hopefully I will not need to remove the fuel tank.

I have been able to confirm that the drive shaft was bent by rolling it on kitchen counter and looking for gaps between the counter and the shaft. As it turns out it is bent slightly. Good thing I ordered the shaft last week. I was worried that it was a mistake and that I would be able to reuse the one that was already in the boat.

What do you guys use to tighten the bolts around the packing box? Those babies are 2” or greater! Home Depot and Loews don’t carry any thing that big. I have been using pipe wrenches but they leave big marks in the side of the bolts. There must be something better than what I am using that does not cost a ton of $$.

[Juice75]

I believe that the stuffing box nut doesn't need to be very tight. I think you're supposed to tighten it by hand, then turn it an additional 1/4 turn. I just used a pair of channel lock plyers, and they did the trick. You should get about 2-3 drops of water per minute from the stuffing box nut. Those drops keep the nut cool. If you tighten it too much, it could get hot and freeze on the shaft.

I think all of that is correct, but someone correct me if I'm wrong.

[No Paddle]

Thanks for the info on the stuffing box.

I ended up taking out the fuel tank. There was no way that I was going to be able to get in there to do what needed to be done without removal. The take away from today’s lesson is to wreck the boat on an empty tank. Despite recommendations I did not bother siphoning out ¾ of a tank. Suffered small splashes out of the fuel nozzle entrance but nothing I cannot clean up with little soap and water. End result will be good as new.

Removed the cotter pin on top of the rudder shaft but I cannot seem to get the rudder shaft off of the rudder arm. Spent lots of tonight hammering away to no avail, I will spend more time tomorrow. Too much hammering late at night makes the neighbors and my family grumpy.

[DKJBama92Mariah]

Hehe. When i replaced my rudder, i worked till 4am. It was the night before the 4th of july so i had to get it done or i would have had a boatload of disappointed young ladies. pardon the pun.

Remeber. The bolt on the tiller arm has to be taken ALL THE WAY OUT. It only clamps the tiller on the rudder, but it also locks into a slot on the rudder shaft. Mine was broken at the shaft so i just pulled it out from the inside of the boat with the tiller arm still on it. After that, i just used the vice on my workbench. You could probably get a puller at an auto parts store. Autozone has a loan-a-tool program, and they have several different types of pullers. You just pay a deposit and they refund it when you bring the tool back.

How the HELL did you you get that tank out full of fuel. I drained mine just because it was so heavy. 30 gals x 7lbs/gal = 210 lbs!

Good luck!

Cheers,
DKJ

[No Paddle]

All the new replacement parts are on the boat, gas tank is back in and I was just about to give my self a pat on the back and I look down the center of the boat and realize that the prop and drive shaft are not directly centered down the center of the boat. When looking at the rear of the boat, the center of the prop is not centered with the rudder, it is a little over an inch off of center. Please look at the pictures.

During reassembly, I screwed the drive shaft to the transmission then slid the strut on the shaft and went directly up and screwed the strut to the hull. So the degree of angle would have to be in direct relationship to the tranny and engine. Nothing appears to be crooked and the prop spins freely with no binding or resistance.

Is this offset normal? Do I need to remove the strut and align the engine then reinstall the strut? I am at a loss. Please help. The glue is drying and it will be easier to remove before it fully cures if I need to do something.

Thanks,

[KenG]

You assembly looks OK. The offset is normal for a Supra.

--KG--

[DKJBama92Mariah]

I concur with Ken. Everything looks great. The boat is built with the offset so you can pull the driveshaft without removing the rudder. Good work and congratulations. There is always a great sense of accomplishment when you tackly a project this big and realize you saved yourself $1,000+ in labor charges.

Now, you might consider a depth finder so this disaster doesnt happen again.

Cheers,
DKJ

[Salty87]

nice and shiney looking gear!

[DKJBama92Mariah]

No Paddle,

How did you manage to get the fuel tank out? I needed to pull mine last month and we could not get it through the ski locker opening no matter which way we turned it.