1996 OMC Cobra / Volvo SX gaskets

[Lpgc]

Yes, you need to remove the drive again. This time I would make a cart for the drive. Set up the height so you can trim the drive horizontal and you can raise/lower the front of the trailer so the drive sits on the cart. Then you'll find it's very easy to remove and re-install. On the engine mounts I would try to get both sides at equal height, then adjust both up or down until the alignment tool slides right in. With grease on the end of the alignment tool, if you see deeper spline marks on top of the tool, raise the front mounts. You don't need to mess with the rear mounts.

The nuts on top of the motor mounts are meant to be lock nuts to prevent the lower nut from moving.

Thanks. I'll try to get around to removing the drive again over the next few days. The main reason I'm concerned about the rear mounts is because I removed and refitted this engine a couple of years ago, I remember having some confusion about how the rear mounts fit together.

When I've removed the drive will it be OK to leave it on it's side without dropping the gear oil? I'm thinking too much gear oil might move up to the upper end of the drive but it'll be months before I use the boat again so even if that happens the oil will drop back to where it's supposed to be when I reinstall the drive.

The top nuts on the front mounts are locking nuts, the nut(s) below don't seem to be locking nuts... But there are 2 nuts below on the port side and only 1 nut below on the starboard side - maybe the starboard side dropped if the 2 nuts below are supposed to be torqued together to lock each other?

 

[Lou C]

Agreed Horigan's way is the best way. Build a cart, or modify a motorcycle jack to make the drive R&R easier, then get the alignment right, then you're good and won't have to worry about stressing the coupler due to the alignment being off.

 

[Lpgc]

A cart would be best but I didn't struggle when I used the ratchet strap. I'd need to buy/make the cart so I'll probably try using the ratchet strap again next time. Another thing I like about the ratchet strap is it has a bit of elasticity, making it possible to make minor angle adjustments just by slightly pushing on the drive.

 

[Lpgc]

I removed the drive again, it took some effort to remove it.

The alignment tool still slides in easily and is still giving equal spline witness marks.

I changed the engine coupler when I rebuilt the engine a couple of years ago because 1. I thought the splines in the coupler might've been a bit worn and 2. The rubber in the old coupler wasn't seated against the rear of the unit in one area.

I still have the old coupler and tried putting the end of the alignment tool through it, it's not a tight fit on the alignment tool but witness marks do change a bit if I put some sideways force on it when I push it in and pull it out. Then I tried the old coupler on the drive input shaft splines, that is a much tighter fit. So I'm not convinced that checking alignment using the alignment tool is likely to give accurate results because it doesn't seem tight enough in the coupler splines to give accurate enough results. Even if I put a lot of sideways force on the alignment tool going into / out of the old coupler it's difficult to see much difference in the witness marks.

I read somewhere that it could be possible to have the engine out of alignment but it seem to check OK using the alignment tool because the alignment tool only goes through the gimble bearing and into the coupler (and the gimble bearing axis can move) which is only 2 points, where-as it's different for the drive because the input shaft of the drive also has the rear fixed in one position where the shaft enters the drive at the other side of the Ujoints which is 3 points. Do you think this could be what's happening in my case? I'm thinking maybe it would seem to line up OK using the alignment tool anyway because as the engine moves while I'm adjusting its height the gimble bearing can just tilt to allow the alignment tool to go through it and into the coupler? If so, is there another test I could do such as check the position of the rear of the alignment tool relative to the 6 drive mounting studs?

 

[Lou C]

You raise some very good questions but I don’t know the answers to most of them not having had to adjust the alignment on my boat. I would however, rotate the engine 90* from where you started and continue to where you were at the beginning (0*, 90*, 180*, 270* and 360*) and check again, Do this till you end up where you started checking alignment each time. I would be surprised if it was the same all 4 times it can be checked.
The other thing is that I/Os use what’s called a double cardan u-joint assembly, this allows somewhat more movement than if it were a simple single u-joint driveshaft.