Alpha 1 Gen 2 seals.

[Simoniz]

Im trying to decide if my Alpha 1 Gen 2 drive unit is pressure tight or not.

Ive made a pressure test rig out of a few bits of pipe, a tyre valve and a plastic threaded fitting but Im not sure if the threaded fitting is sealing against the drive. Bond O kindly advised putting an o ring against the shoulder of the screw in part but there is hardly any shoulder there so the o ring just ends up squashed out of the way when I tighten the threaded part into the drive.

During the summer I had to add an inch of drive oil to the reservoir but seemingly all at once, ie there was no steady drop in the oil level so it could be that there was an air bubble that worked its way out after the oil was filled at the beginning of the summer.

On the other hand, it could be that the drive oil is leaking out. when I drained the oil at the end of the year, it was dark but no signs of water in the oil. Having pulled the drive from the bellhousing theres no sign of oil leakage at the driveshaft and theres no sign of any oil leakage at the propellor shaft which leaves me to suspect the 2 sealing points in the middle (bottom of drive shaft housing and top of gear housing).

I may as well split the drive unit as it wouldnt hurt to replace the impellor but the question is, is it possible to replace the seals when the upper and lower units are separated for access to the water pump? I think the seals at the top of the lower unit are accessible as they sit in the carrier assembly (part no 807929A1), but how about the seals in the upper unit?

Also, the parts diagram shows 2 possible types of seal. For both the upper and lower units there is the possiblity to have 2 seals, part number 26-66302 or 1 seal, part no 26-864319, depending on the serial number of the drive, serial no OM 400410 and below, 2 off 26-66302 are used and for serial no OM 400412 and up, 1 off 26-864319 is used.

I dont know the serial number of the drive but the engine number is OL 634881. The boat is a 2001 model, if that helps.

Any advice about the ease of replacing the seals (and the probablity that they are shot after 10 years) and the seals which my drive uses would bee very welcome.

 

[Bondo]

Re: Alpha 1 Gen 2 seals.

During the summer I had to add an inch of drive oil to the reservoir but seemingly all at once, ie there was no steady drop in the oil level so it could be that there was an air bubble that worked its way out after the oil was filled at the beginning of the summer.

On the other hand, it could be that the drive oil is leaking out. when I drained the oil at the end of the year, it was dark but no signs of water in the oil. Having pulled the drive from the bellhousing theres no sign of oil leakage at the driveshaft and theres no sign of any oil leakage at the propellor shaft

Ayuh,... I think you're chasing a ghost that doesn't exist....

 

[Simoniz]

Re: Alpha 1 Gen 2 seals.

Hmm Maybe, Ill have to get the pressure testing sorted out so I know for definite if its sealed or not.

If I do end up replacing the oil seals, are the seals easily replacable just with the upper and lower units separated?

Also, when pressure testing the drive, is it necessary to pinch closed the oil pipe that runs between the reservoir and drive to make it airtight?

 

[cr2k]

Re: Alpha 1 Gen 2 seals.

No those seals go in form the top of the upper housing so you have to pull everything out first. If you do this I would advise to clean the housing real well, put the seals in one up one down and run a thin bead of superglue around the edge to help hold the seals in. They can be upset easily by not being careful enough when putting the lower back in, as they are plastic seals and have no metal band to help them stay put. One of the poor redesign issues on the gen II. But I am sure it made for cheaper casting and/or assembly.