Transmission Lock Nut

[tallnfast]

I have had a problem with the drip nut. I couldn't get at it until now, since I need to remove so much to get at it.

My questions are:

1. How tight to make it?
2. Does it drip from the nut or the black rubber sleeve?
3. I have no idea how to do work on this at all, any advice would be VERY appreciated!
4. Should I replace any of it with something new? ex. the black rubber sleeve?

Thanks in advance for your help, as I already know there are some smart Supra people here!

[DKJBama92Mariah]

The rubber hose part is called the shaft log. It should not drip from there. You have to pull the shaft out of the boat to change it.

The big bronze nut around the driveshaft is called the packing nut. Flax packing rope (or nowadays gore-tex synthetic packing rope) is wrapped around the shaft inside the packing nut. As the packing nut is tightened, it squeezes the rope against the driveshaft to keep water out.

1. Just tight enough to where it doesn't drip with shaft not turning. A few drips a minute is expected while the shaft is turning when using flax packing. It is imperative that you not overtighten the packing nut because it will cause drag and friction against the spinning shaft and heat up the packing, eventually ruining it. If, over time, you must continue to tighten the packing nut to keep the boat dry, then it is time to replace the packing rope. Final packing nut adjustment should be done on the water so you can check immediately after running the boat to make sure the packing nut is not hot.

2.The drips come out of the center of the nut where it meets the driveshaft.

3. That we can help you with

4. I would replace the packing rope with the gore-tex stuff if it is leaking a lot. The shaft log hose itself looks rough, if it were my boat I would replace it. For you, it depends on whether you want to pull the driveshaft. You will need a prop puller and perhaps one other specialty tool to do the job. How long is your boat? 19, 21, or 23.

On a positive note, if you do pull the shaft, it makes it much easier to install the new packing rope.

[tallnfast]

Thanks for the info.
My boat is 19'6" I think, why do you ask?
Is taking the prop shaft out of the boat hard?
Why do I need to pull the prop? Can't I just pull the prop shaft out of the boat?
Also if I plan on replacing the shaft log and packing rope what do i need to know, is it really hard? Just don't want to screw anything up with that part of my boat.....

I suppose I can just call skidim and they can tell me exactly what size shaft log and packing rope I need?

Thanks for your help, it really helps me try new things and avoid big mistakes!

[DKJBama92Mariah]

Thanks for the info.
My boat is 19'6" I think, why do you ask?

On shorter boats, depending on the coupler, you may need an extra -shallow socket to get in between the coupler and transmission output flange to remove the nut that holds the coupler onto the driveshaft.



Is taking the prop shaft out of the boat hard?

Not really.Its harder than changing a car battery, but moderate technical abilities and advice from this forum can get the job done.



Why do I need to pull the prop? Can't I just pull the prop shaft out of the boat?

The rudder is in the way. I don't think it'll come out without the prop hitting the rudder. To be honest, I've never tried though.



Also if I plan on replacing the shaft log and packing rope what do i need to know, is it really hard? Just don't want to screw anything up with that part of my boat.....

As was stated above, it's not hard,just take your time. We can take you through it step by step if needs be. The drive systems on these boats are incredibly simple though.



I suppose I can just call skidim and they can tell me exactly what size shaft log and packing rope I need?

Yes.



Thanks for your help, it really helps me try new things and avoid big mistakes!
Before we get too ahead of ourselves here, how old is this boat? Pictures can be deceiving and that shaft log may still be fine. I don't want to talk you into tearing apart your drivetrain when a simple packing replacement may fix you up fine.

[docdrs]

sounds like maybe he just needs to repack it........ looks like a DD so 1/4"


Replacing and Adjusting the Shaft Packing.
- Replace the shaft packing. Be sure to install two or three pieces.
- Loosen the jam nut on the shaft-packing gland.
- Back the gland nut off the packing gland assembly.
- Dig out all the old packing material.
- For a one inch shaft, cut two to three pieces of 1/4"dia. packing material strips so they are 4 1/8". Place one of the packing strips into the packing nut. The end should butt together. Place another piece in the packing nut, this time orienting the seam 180 degrees from the seam of the first piece.
- Slide the packing nut up the shaft.
- Slide the shaft through the Packing gland assembly and into the strut.
- Screw the packing nut onto the packing gland assembly. Tighten it up as much as possible by hand. Then using a wrench, turn the nut a 1/2 a turn forward and a 1/4 turn back. Then turn the nut a 1/2 a turn forward and a 1/4 turn back. Then turn the nut a ½ a turn forward and a 1/4 turn back. This will pack the packing fairly tight.
- Back the packing nut off the assembly again. Then thread it back on. Tighten it only as tight as you can get it using your hands. This should be almost the perfect tightness for the packing gland so that it does not leak, yet not too tight so that the packing burns up.
- Tighten the Lock Nut up to the Packing Gland Nut.

If you want to add the third piece of packing, do so when you back the nut off after you packed the packing. Then tighten the nut only as tight as you can get it using your hands. This should be almost the perfect tightness for the packing gland so that it does not leak, yet not too tight so that the packing burns up.

3/16” PACKING FOR V DRIVE
¼” PACKING FOR DIRECT DRIVE

Ideally, you want 1 drop of water every 30-45 seconds when the boat is in gear at idle. (Be sure the boat is in the water)