1988 Alpha One lower impeller change progress, remote shift in forward?

[petergordon]

I have a Doral Classic 200 with a 4.3L Alpha One. Recently, my first water trip this year, the temperature indication started to rise at idle. Had nerer seen that before. At speed, cooled nicely. I suspected the impeller so I'm changing it.
Couldn't get it to slip up the shaft, so I cut it off with a dremel. 7/8's through, then split it with a flathead screwdriver twist. Vanes are curved and have set up. I would have thought that the impeller was offset from the cut it runs in, but guess not.
So, I left the upper on the boat. Is it suffice to put the remote control shift lever in fwd when reassembling? I have the manual, but I didn't drop the upper half to get at the shift shaft.
BTW, I don't think the impeller was the issue, I'll replace the t-stat next.

Peter

 

[fishingdan]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

Per the manual, the shifter needs to be in forward to drop and reinstall the lower unit.

You are right, it doesn't sound like an impeller issue. Good to change it anyway.

 

[petergordon]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

I left he drive shaft housing attached to the boat, and did not need to put the shifter in forward to drop the gear housing. I'll put it in fwd for the re-install though.
The drive shaft in the gear housing has some up-down play. I didn't touch anything with the drive shaft, is the play ok?

 

[petergordon]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

I have replaced the impeller. I'm having trouble reassembling the lower half to the upper half. The shifter is fine, but it is bottoming out. After removal, it appears that the drive shaft is grabbing the lower oil seal and dragging it up. I have read where people have chosen not to reinstall the o-ring. Perhaps it is this that is dragging the lower seal up?

Peter

 

[petergordon]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

I pulled the lower oil seal out. Mainly to have a look and replace. Glad I did. Looks torn up. Spring was still intact. I'll get a new one and install from below. Does this seal go inside what looks like a cup, larger than the female drive shaft? Does it completely fill the void inbetween the edges of the female splines and the "cup"? I measured the distances, and the o-ring on the drive shaft would have to push up and past this oil seal to sit proper.

 

[ziggy]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

the pic looks about like where i dropped my seal off at. i think there's a proper driver to install it. but i've been led to believe i can drop it off wherever, within reason. reason i say that is because i'd guess you'll be able to see exactly where the seal was at by looking at the drive shaft. seal wear. if you have it. you need to determine if the drive shaft is serviceable. i've droped the seal off in a slightly different location on one drive i've got, another i speedy sleeved the wear.

what oring. the one on the drive shaft. i'd have thought a alpha1 wouldn't have the oring on the driveshaft.

for ease of install, put the remote in fwd. the drive in fwd. use a bungee to help load the prop ccw to keep it in fwd.

i've had my share of griefe putting my lower back on too. best i can tell. it's the water pipe and water tube guide that give me trouble. i've found it works best to have the waterpipe in the water pocket cover, and the guide in the water pump housing. if it really gives ya a hard time. take the upper off. you'll be amazed at how easy the upper and lower are to reassemble on the bench. by yourself.

Vanes are curved and have set up. I would have thought that the impeller was offset from the cut it runs in, but guess not.

i don't understand that statement. the impeller is a circle, the impeller housing is a circle. to make it pump, the impeller is offset inside the housing. some vane are real bent over, some are strighted out oppisite the real bent over ones. the real striaght vanes bring water in. as the vanes get bent over, the squish the water out and send it off towards the engine under pressure.

 

[petergordon]

Re: 1988 Alpha One lower impeller change progress, remote shift in forward?

Thanks for the help Ziggy.

I'm handy, but not used to this type of work. What I was looking at was the metal part left in the housing after I pulled the spring and rubber out of the oil seal. Knowing that, I'll pull out the old metal oil seal ring, buy a new one, and pressit in so that it's flush with the housing. Because of the "lip up" install of the lower oil seal, I'm NOT going to put the o-ring on the drive shaft. It looks like it'll pull the lower oil seal apart during re-install rather than just slide past.

Thanks for all the help. I think I'm on my way!

Peter