Alpha1 Gen1 water pump replacement problem

I have a Alpha 1 Gen1 and i ch

I have a Alpha 1 Gen1 and i changed the Impeller in it. I was putting the lower unit back on and I had trubble putting it on. we got it on and we tightened all the nuts. Once it was back on the prop would not spin freely in nutral. we took the nuts back off and the unit would come apart again. any ideas???

"Make sure the lower half is l

"Make sure the lower half is locked in forward ( spin the prop in the forward direction while turning the gear shift in the forward position, it should lock and spin the gear shaft)Also make sure that the gear shift lever in the front is in the forward position. As long as both are in the forward position when you put them together the gear shifter on the lower unit and the boat should line up straight and the boat will thus have neutral. If it isn't lined up just right, the lower end will lock in reverse."

The problem is the lower unit

The problem is the lower unit is on and it is stuck on and it cant come off. i turned the prop and it just keeps clicking. and i just need to know how to take the lower unit off becuase it is stuck on.

OH!
Sorry.
The only thing yo

OH!
Sorry.
The only thing you can really do is get two people together and force it off. it probably just seated very good.

the problem is i put the lower

the problem is i put the lower unit back on after impeller change. then it wont come back off because the lower unit is in a different gear then the boat. do u know what i mean?

take the drive off the boat.

take the drive off the boat.

"Sounds like a dumb question,

"Sounds like a dumb question, but are you sure you have all the bolts removed?
There's 7 total.
Even if the shift linkage were jammed, it should come apart. maybe bar the engine over a little in each direction to loosen any strain off of the vertical shaft splines.
If you start using a pry bar, be very careful and don't apply a ton of force to one spot.... maybe try prying on both ends or both sides evenly. Be careful of the little oil seal area."

"max- put one of the bolts in

"max- put one of the bolts in with the nut to keep the upper and lower from separating (you don't need them tight, just get them started). Make sure all of the bolts are out and the nut at the front, near the shift shaft. You have a splined shift shaft and if yo got it to go in when it wasn't in forward, it's jammed so you will need to pry the two halves apart but don't use a metal prybar. The gear cases are aluminum and steel will damage them. Start with a couple of pieces of hardwood and pry the two halves gently- the cavitation plate can break if you pry too hard. Also, try to rotate the rear of the lower gear case as you pull down and maybe it will come off.

Does it go into forward and reverse when you shift? To check forward, you rotate the prop in the same direction as when it's in reverse and you check reverse by rotating the prop in the forward direction."

Troy... What do u mean by &#34

Troy... What do u mean by "bar the engine over"? the shifter is just binding up alot. it will move from drive to nutral to reverse but nothing happends to the lower unit. and once i get the lower unit off will i have to replace the shifter splines?

"He may mean that you should u

"He may mean that you should use a breaker bar with a socket to turn the motor. If you need to do this, remove the spark plugs- it'll turn a LOT easier.

The splines won't wear off or be flattened- they're stainless. It could just be one spline off and binding from that. Either way, there's not an easy way to grab the lower case and pull it off of the upper but you might call a Mercruiser dealer and ask if they have had to do this.

The main thing is, never use the bolts to make things go together. If it doesn't want to go normally, don't force it. It should slide together without much persuation. Also the input shaft where it slides into the coupler needs to be greased with marine grease or spline grease annually. If you didn't remove this and have suspicions about previous maintenance, get the drive seal and grease it, and check the universal joints for grease fittings. If it has them, grease those, too."

"I do mean to turn the engine.

"I do mean to turn the engine... not a whole lot, just wiggle it back and forth a bit so that if the splines on the vertical drive shaft, (from the lower unit), are hanging up inside the driven gear (in the upper unit), it may free it up. Jim has a good point to loosely put a nut and bolt on the two halves, so the lower unit doesn't drop off and hit the driveway if you try this.
It's surprising that you can move the shift lever at all. Are the two parts of the shift shaft lined up? You can see where the two parts of shift shaft come together, that part is outside of the casings on the front end of the drive."

Troy i can get to the shift cu

Troy i can get to the shift cuppler while the unit is still on a wiggle it loose?

"1)Trim the drive all the

"1)Trim the drive all the way up (trailer position), or as far up as it will go without causing any more damage. It should be in this position for removing the lower unit anyway.
2) Look at the front (leading edge) of where the lower unit mates to the upper unit. Just above the joint there is a cavity. Inside the cavity you will see a small tube for the speedometer... disconnect it and pull it back out of the way. Behind it, you will see where the two parts of the shift lever come together. The lower section coming out of the lower unit has a 90° bend which, when lined up, slips into the upper part, which has a plastic recepticle.
Are those two peices together? or aren't they?
If they aren't, it doesn't makes sense that the shift lever,inside the boat, could be moved through its full travel of forward to neutral to reverse like you mentioned above. If they are lined up, the binding is being caused by soemthing inside the drive.
One posibility for this binding is the vertical drive shaft splined end is stuck inside the driven gear in the upper unit. That driven gear, through a drive gear, another drive shaft, a couple of u-joints, yet another length of drive shaft, the engine coupling and the crank shaft, is connected to the vibration damper on the front of the engine.
3) Wiggle that back and forth (a quarter turn each way)... you'll need a socket and a breaker bar. Pull the spark plugs if you feel so compelled but I don't think you really need to. It's not like you're going to make several revolutions. If you want to go for it. This will, maybe, loosen any tension between the vertical drive shaft and the driven gear, and the lower unit will fall off."

"Troy, I am trying to re-insta

"Troy, I am trying to re-install my lower unit and cant get it all the way in. Will it help me to "rock" the engine also?

Thanks"

"Maybe just turn it a few degr

"Maybe just turn it a few degrees to help the splines line up. You can also rotate the prop, clockwise, with the shift lever in forward.
A little grease on the splines helps too.... also helps when it comes time to pull it off again."

"Mercruiser has a tool for rot

"Mercruiser has a tool for rotating the propshaft backward for rotating the drive shaft and since it doesn't need to rotate far, it won't do anything bad to the impeller. With the drive in Forward, rotate the prop shaft backward a little and the splines will line up.

The impeller should be lubricated, anyway. Otherwise, it'll be dry when it first starts. The splines are definitely supposed to be greased.

WIth 15 splines, the shaft only needs to rotate a little bit in order to get it to line up. Bumping the starter will go past the point of lining up and coincidence is the only thing that would let it go it.

The other thing that could be keeping the lower case from going on is the tube from the raw water pump output. Trim the drive up all the way and you'll be able to see this and you can then make it go together."

Any problem with using standar

Any problem with using standard gear oil instead of marine?

one more question for u troy.

one more question for u troy. i have a alpha 1 gen 1 i dont think it has the speedometer on the lower unit it has it on the transom. would that change anything?

"The speedo could still be use

"The speedo could still be used, coming from the lower gear case. Look in the area of the front bolt and shift shaft. You'll probably see a black tube with a plug in the end, tie wrapped in a loop."

"I recently replaced water pum

"I recently replaced water pump in lower unit on a Mercruiser 5.0 Alpha 1 and the water tube was not allowing the units to slide together. What my problem is after getting everything back together the gear shift lever goes into forward okay but the throttle is hard to push forward, like its in a bind. Why would this happen?}"

"Since your on this subject, I

"Since your on this subject, I just put a water pump in my alpha one and I can't get it to shift into reverse after its all together. I can shift into forward but not reverse its like its binding up. I have done the water pump before but now I don't get it. I had the whole drive off and put it back together, then took the lower off thinking it wasn't in full forward when I put them back together but that didn't do it. the shift lever is in the right position. I guess I'll take the whole unit off again and see if there is something wrong with the shift cable

Thanks for any help."

"Ok Figured it out, I thought

"Ok Figured it out, I thought the lower unit was in forward but it was in reverse.

That's why you should use that service manual you have! lol"