Alfa 1 gen 2 shift Lower Shift Shaft seal change

[ulster1]

Winterized the drives and found milky oil in star drive, removed the drive drained and refilled with engine oil until I get a chance to work on it, Plan to do a pressure test but I believe it is leaking at the shift shaft seal, when I confirm this I will separate the top and bottom drive and remove the seal speedo assy and exchange with new, My question is this ----- do I just lock the prop shaft in the forward position which means the angle on the shift shaft is straight out, then loosen the seal assy and pull the shift shaft out? (without the prop shaft moving) then reassemble by pushing the shift, shaft back in to the exact same position.
Great forum great advice.

 

[ENSIGN]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

I wish it were that easy,when you pull the shift shaft out the clutch dog is going to pop out of place and the shaft will not go back in place.you're going to have to remove the prop shaft first to relieve the spring tension.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Lower Shift Shaft Stuff
So I guess this link is wrong??
If I follow the info on this link correctly it is saying to clamp the lower drive in a vice and clamp the prop shaft so it cannot move then remove the bolts for the shift shaft seal and pull the assy straight out, Replace the assy with the new and reinstall.
You are saying that the clutch dog will pop out of place even with this method.

 

[Don S]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

I've replaced many of the shift shaft bushing assemblies and never had any problem with the clutch dog moving.
I had the lower unit in a drive stand setting level. Unbolted the bushing, lifted the assembly up, and put it all back no problems.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Thanks Don, I feel better now !! I will be tackling this once I get home from my vacation and will post the progress when complete.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

I've replaced many of the shift shaft bushing assemblies and never had any problem with the clutch dog moving.
I had the lower unit in a drive stand setting level. Unbolted the bushing, lifted the assembly up, and put it all back no problems.

Alfa 1 gen 2
Now I am stumped I set up the pressure test at 10psi and for the last 3 hours no pressure drop?
I was sure it was the shift seal but after spraying it with soapy water no bubbles?
I am unable to see the seal below the water pump but if the pressure is not dropping where is the water getting in?
I am going to leave it overnight and see if it maintains pressure if it still has the pressure what would be my next move?
In reading the threads I see that a vacuum test is not really necessary.

 

[Don S]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Winterized the drives and found milky oil in star drive, removed the drive drained and refilled with engine oil until I get a chance to work on it, Plan to do a pressure test but I believe it is leaking at the shift shaft seal,

You drained the engine oil out of the drive before you did the pressure check didn't you?

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

You drained the engine oil out of the drive before you did the pressure check didn't you?

Yes Don I did.

 

[Don S]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Did you turn the shafts and shift gears while pressurized? It may leak when actually running.

PS: you can do a vacuum check, but it may not hold full vacuum because the ujoint shaft seal will leak.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Did you turn the shafts and shift gears while pressurized? It may leak when actually running.

PS: you can do a vacuum check, but it may not hold full vacuum because the ujoint shaft seal will leak.

Yes with the 10psi in the drive I rotated the input shaft several times and then put the drive in reverse and continued rotating with no drop in pressure. I am rotating the splined shaft by hand.
I also pulled and pushed on the prop shaft thinking that if it moved it could be pulled off the seal area, I did like wise with the shift shaft pushed pulled and twisted with no change in pressure.
I am now doubting myself that the gaskets for the filler and vent plugs could be the problem but I change them each year as I check the oil for water, so I doubt it could be that?
Not sure what my next move is?

 

[tazrig]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

I had a similar experience to what you're going through. Try taking out the filler and drain plug gaskets and making sure the metal that the gaskets sit on is COMPLETELY free of any gook. Believe it or not it doesn't take much foreign matter in there to mess things up. I had checked everything you mentioned above and passed the pressure test as well. I too replaced my little gaskets every year but still had milky oil. A mechanic suggested cleaning in back of the gaskets before installing the new ones. I thought he was crazy but I had tried everything else. After doing that the milky oil went away.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

I had a similar experience to what you're going through. Try taking out the filler and drain plug gaskets and making sure the metal that the gaskets sit on is COMPLETELY free of any gook. Believe it or not it doesn't take much foreign matter in there to mess things up. I had checked everything you mentioned above and passed the pressure test as well. I too replaced my little gaskets every year but still had milky oil. A mechanic suggested cleaning in back of the gaskets before installing the new ones. I thought he was crazy but I had tried everything else. After doing that the milky oil went away.

Thanks Tarzig for the reply I can only hope it is as simple as that, I just checked this am and the pressure is still holding so here is my plan. I will clean the area in the back of the gaskets and replace the gaskets on the vent and drain plugs re fill with engine oil for storage until close to launch in April (This way I can be sure all the moisture has been removed because it will have been my second oil change and flush with engine oil) Just before launch I will drain and refill with gear oil and hope it is good for the season as I have no way of checking until she comes out of the water in the fall. (Unless I go to the marina and have her lifted out to check)

 

[tazrig]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Thanks Tarzig for the reply I can only hope it is as simple as that, I just checked this am and the pressure is still holding so here is my plan. I will clean the area in the back of the gaskets and replace the gaskets on the vent and drain plugs re fill with engine oil for storage until close to launch in April (This way I can be sure all the moisture has been removed because it will have been my second oil change and flush with engine oil) Just before launch I will drain and refill with gear oil and hope it is good for the season as I have no way of checking until she comes out of the water in the fall. (Unless I go to the marina and have her lifted out to check)

On the Alpha 1 Gen 2 drives there is a dipstick screw on the top of the drive (same size as the fill and vent screw with the same size gasket) You can check the oil level and color from that, assuming the top of your drive sits above the water line.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

On the Alpha 1 Gen 2 drives there is a dipstick screw on the top of the drive (same size as the fill and vent screw with the same size gasket) You can check the oil level and color from that, assuming the top of your drive sits above the water line.

My drive has the oil reservoir on the top of the motor with the alarm if the oil level drops to low, so I do not have the dip stick. It is now 48 hrs and still no drop in pressure so I am going to assume it is OK and follow my previous post.
My drives sits low in the water and I have a large swim platform so no excess until it is out of the water.
Thanks for the info.

 

[Don S]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Make sure you use new gaskets on the fill, vent, and dipstick. They have caused many leaks because people keep reusing them. The one where you attached your pump may have been the one leaking.

 

[ulster1]

Re: Alfa 1 gen 2 shift Lower Shift Shaft seal change

Make sure you use new gaskets on the fill, vent, and dipstick. They have caused many leaks because people keep reusing them. The one where you attached your pump may have been the one leaking.

After 48 hrs no drop in pressure so I am going with the gasket leaking on the vent, I will be extra careful with these from now on.
Thanks for the input.
Regards
Ulster1