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After impellar replacement problem getting lower unit to go in gear alpha1 gen2

G

gthoman

New member
Hello All,

I have a 1996 SeaRay 175 bowrider that has a mercruiser 3.0 alpha1 gen2 I/O. I disconnected the lower unit to replace the impellar. I followed directions to have it in forward gear before removing it and made sure to add bungies to keep the prop from moving. I put it back in and can tell its not in gear, prop will spin both ways in forward, actually seems to be wherever the handle is?? So have pulled it off again and trying to make sure they are both in the same gear(upper and lower) I pushed the handle all the way forward inside the boat, and had read somewhere that to make sure the lower unit is in forward gear, turn the prop counterclockwise while turning the shift shaft clockwise and when the prop locks in place it's in forward gear. Mine prop never locks in place, I can continue to turn the prop counter clockwise. Did I miss something? Is this the correct way to make sure the lower unit is in forward? Any help would be greatly appreciated
Gene
 
I am experiencing similar problems. I paired to 300 Chevy inline 6 with two alpha one gen one stern drives. Had to replace the top bearing in the upper gear case and gimbal bearing. When I put your gearcase back on and put foot back on I can't get the shifter cables to move freely. Really need some help with this. It's not just one outdrives it's both...the foots are sierra marine and new. Years old but no use. Shift shaft appears to working right. When I tighten last thread putting foot on it binds. Maybe I'm not putting it in right with the upper gear case bolts to gimbal housing.
 
ready2bnwtr said:
I am experiencing similar problems. I paired to 300 Chevy inline 6 with two alpha one gen one stern drives. Had to replace the top bearing in the upper gear case and gimbal bearing. When I put your gearcase back on and put foot back on I can't get the shifter cables to move freely. Really need some help with this. It's not just one outdrives it's both...the foots are sierra marine and new. Years old but no use. Shift shaft appears to working right. When I tighten last thread putting foot on it binds. Maybe I'm not putting it in right with the upper gear case bolts to gimbal housing.
Click to expand...
Ayuh,.... You might have several issues going on,.....
Are you using the original transom assemblies, aka: the Mod. 1s,..??
If so, did you change to the shorter input shaft on the upper unit,..??

When you put the lower unit onto the upper unit, did you securely hold the prop shaft, so it couldn't slip into neutral,..??

Merc's have to be put together in forward gear, or it won't work,.....
 
Make sure the washer was left on the lower unit's shift shaft or, if it was removed, it was reinstalled. Did you do anything to the oil seal for that shift shaft (it's the short, stubby one with splines)?

If that stainless washer wasn't used, the Bronze part that mates with the upper shift shaft will drop down onto the rubber washer and it will be too low to engage with the 'foot'.
 
Yes I used the original transom assy's.i didn't remove any of that. When I purchased the boat it had 300 six cylinders that weren't marine engines. Well the engines were locked up. I managed to get them freed up and got the engines running beautifully .launched the boat (1974 Stamas 24') .starboard engine had whole through the where the thermostat housing bolts to the head and the first cylinder. Long story short the starboard motor went down. I ran on the port engine to get back to the harbor.the port engine had a hole in the pan or rear seal leak not sure which.these engines are tightly squeezed in to the engine compartment.so it was hard to tell which it was. So I went and bought a 250 inline six and went about swapping the starboard engine. I changed the lube in the outdrive when I got the 250 up and running. Well I didn't have the right amount of gear oil in the outdrive. So when I went to test the engine the upper bearing in the gear case locked up.(I'm sorry for such a long story but this has been a battle.)I love the old boat. It's not only antique but it's a fine boat. I started out with only 500$ in it. So I swapped the outdrives just to try and get one completely up and going.i had no problems with the shifting at this point. Checked all adjustments everything was perfect. When the outdrive burned up and locked up it burned the coupler up.well while I had went back to the drawing board ,as they say, I found two marine 292's 200hp inline six's with the original MII outdrives. They only paired these 292's with the outdrives two years. 1969 and 1970. The motors has been gone through and had 26 hours on them. It was a great buy bc of how much just one of the 292's cost by themselves. They also had closed coolant with sea water heat exchangers. So no sea water had ever been inside the engines. Then I swapped the flywheels and bell housing's that were originally in the boat when I bought it. Installed the engines and they are beautiful. Run like champs. In comes the outdrive issues.i replaced the gimbal bearing. Replaced the bearing in the upper gear casing. Changed the water pumps(in the foots). These engines also have sea water pumps on the engines. When I put the strength drives back on the gimbal housing I wasnt sure about how that connects with the shifter cable. I have bought a manual. I've worked on boats and cars my whole life. I don't consider myself a mechanic bc I don't do it for a living. But I could if I wanted to. I'm not an amateur by any means. I've have the issue where when I tighten the foot to the upper gear case the last thread when I tighten it the shifter won't move .if I loosen it a thread it will work. Now I do have a stainless washer on the shift shaft.but it's kind of concave.is it supposed to be flat? And is it just a stainless washer? I'm asking bc I will replace it with a new one I just didn't know if it was just a washer. Look guys I really do appreciate your help. Nothing would make me happier then to be sitting at the oil rigs thirty miles out in the Gulf with two Chevy six cylinders. Not outboards.
 
ready2bnwtr said:
Yes I used the original transom assy's.i didn't remove any of that. When I purchased the boat it had 300 six cylinders that weren't marine engines. Well the engines were locked up. I managed to get them freed up and got the engines running beautifully .launched the boat (1974 Stamas 24') .starboard engine had whole through the where the thermostat housing bolts to the head and the first cylinder. Long story short the starboard motor went down. I ran on the port engine to get back to the harbor.the port engine had a hole in the pan or rear seal leak not sure which.these engines are tightly squeezed in to the engine compartment.so it was hard to tell which it was. So I went and bought a 250 inline six and went about swapping the starboard engine. I changed the lube in the outdrive when I got the 250 up and running. Well I didn't have the right amount of gear oil in the outdrive. So when I went to test the engine the upper bearing in the gear case locked up.(I'm sorry for such a long story but this has been a battle.)I love the old boat. It's not only antique but it's a fine boat. I started out with only 500$ in it. So I swapped the outdrives just to try and get one completely up and going.i had no problems with the shifting at this point. Checked all adjustments everything was perfect. When the outdrive burned up and locked up it burned the coupler up.well while I had went back to the drawing board ,as they say, I found two marine 292's 200hp inline six's with the original MII outdrives. They only paired these 292's with the outdrives two years. 1969 and 1970. The motors has been gone through and had 26 hours on them. It was a great buy bc of how much just one of the 292's cost by themselves. They also had closed coolant with sea water heat exchangers. So no sea water had ever been inside the engines. Then I swapped the flywheels and bell housing's that were originally in the boat when I bought it. Installed the engines and they are beautiful. Run like champs. In comes the outdrive issues.i replaced the gimbal bearing. Replaced the bearing in the upper gear casing. Changed the water pumps(in the foots). These engines also have sea water pumps on the engines. When I put the strength drives back on the gimbal housing I wasnt sure about how that connects with the shifter cable. I have bought a manual. I've worked on boats and cars my whole life. I don't consider myself a mechanic bc I don't do it for a living. But I could if I wanted to. I'm not an amateur by any means. I've have the issue where when I tighten the foot to the upper gear case the last thread when I tighten it the shifter won't move .if I loosen it a thread it will work. Now I do have a stainless washer on the shift shaft.but it's kind of concave.is it supposed to be flat? And is it just a stainless washer? I'm asking bc I will replace it with a new one I just didn't know if it was just a washer. Look guys I really do appreciate your help. Nothing would make me happier then to be sitting at the oil rigs thirty miles out in the Gulf with two Chevy six cylinders. Not outboards.
Click to expand...
The parts list shows the diameter, thickness and hole size for the washer and yes, it's supposed to be flat- it doesn't need to be perfect, it's only there to prevent the intermediate shift shaft going into the recess of the seal below and to prevent bronze on Aluminum contact/wear.

Assuming you'll remove the lower gearcase again, lift the short, stubby shift shaft out and rotate it, checking to see if it goes farther into the splined hole of the Bronze part (intermediate shift shaft) when that's in the forward position (straight ahead). Once you find the position, reinsert the short shift shaft into the shift crank with the gearcase in forward gear. I would bet that allows the upper to mate without pressing on the washer.
 
Lets get your descriptions so we all understand.

1. Lower gear housing (has impeller housing assembly) NOT LEG
2. Upper gear housing (has Ujoint assembly)

When you say you have interference with shifting when installing lower to upper when tightening all the way. Correct?
Is the upper already installed to the gimbal housing?

1. Shift control must be in forward (best to put in full wide open throttle position to be sure for now.
2. The Shift arm (Bronze piece that floats in upper housing) Must be facing forward to line up with Shift shaft in gimbal with outdrive in forward gear.
3. This Bronze shift arm can be 180* out of position so be sure the top flat surface is extending/pointing forward towards transom and it MUST be at 12:00 oclock.
4. Make sure Bronze arm splines are clean and it slides all the way on the lower gear case shift shaft splines easily.

The stainless steel washer that sits on the shift shaft bushing in .062" thick (1/16"). It should be flat, Not concave/bent. If the washer is to thick it can cause an interference with gimbal shift shaft it engages with. It is not uncommon that people in the past who service the water pump assembly have lost or forgotten the washer. The someone puts one on that is to thick that fits over the splined shaft

Maybe some picture would be helpful??
 
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I will check for the washer. The information y'all have given me is good stuff. The upper gear casing is already bolted in. I don't have a problem disassembling any of it. They are actually pretty easy to work on. I have been putting the shift shaft and the brass piece above it at 12 o'clock. Bc I did assemble it 180° out..
I also have a question about the sea water cooling. I know the water pump in the foot cooled the engines before. With this heat exchanger type set up will it be able to flow enough water to cool the closed coolant part of it or am I going to have to install aea water intakes in the bottom of my boat?the sea water pump on the side of the engine is a 1 1/4" hose. I connected it to the 3/4" connection coming out the gimbal housing at the transom? Again thanks for a there help you guys are giving me. Bc I know y'all are busy and the fact y'all are taking the time to help me is very much appreciated. I will also get some pictures.
 
Stick with your shift problem only, for now. Once that is resolved then start asking about other concerns. If you have to many questions the answers will be all over the place.

Yes, the impeller system on Alpha One Gen 1 will supply plenty of raw water to the closed cooling system heat exchanger.
 
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