How/why is an Alpha 1, Gen 1 Sterndrive, better than an MC1?

[Joelk]

I need to repair or replace my MC1 upper unit and have been told that the A1G1 upper and lower units will interchange with the MC1 units(not the individual parts, but the entire units can be swapped)

It seems that used MC1 units are generally a good bit cheaper than the corresponding used A1G1 units. Some of the price difference may be due to the fact that the MC1 units are older, but I assume some of it is because the A1G1 units are better/more reliable.

What about an A1G1 upper unit is better?

What about an A1G1 lower unit is better?

Thanks, Joel

 

[Bondo]

Re: How/why is an Alpha 1, Gen 1 Sterndrive, better than an MC1?

I need to repair or replace my MC1 upper unit and have been told that the A1G1 upper and lower units will interchange with the MC1 units(not the individual parts, but the entire units can be swapped)

It seems that used MC1 units are generally a good bit cheaper than the corresponding used A1G1 units. Some of the price difference may be due to the fact that the MC1 units are older, but I assume some of it is because the A1G1 units are better/more reliable.

What about an A1G1 upper unit is better?

What about an A1G1 lower unit is better?

Thanks, Joel

Ayuh,... Who says it's Better,..??

If ya want Cheap, MC-1 is Better...

Most of the Improvements only affect ya when yer workin' on it...

 

[Joelk]

Re: How/why is an Alpha 1, Gen 1 Sterndrive, better than an MC1?

If the A1G1 units, are not "better", what changes were made that Mercruiser called improvements?

 

[ziggy]

Re: How/why is an Alpha 1, Gen 1 Sterndrive, better than an MC1?

first, there is no alpha1 gen1. it's mc-1, 1-r (revised), 1-mr (major revised), alpha1, then alpha1 genII which is not interchangeable with the previous 4 versions.
anyways.

the way i understand it, and i'm a laymen, shadetree even, is.

one of the major improvements is the removal of the pre load pin in the lower drive shaft. the way i get it is that the pre load pin loads the driven gear in the lower so it maintains mesh with the driven gears. when they removed the pre load pin, they (merc) created a way to have a solid surface for the driven gear to maintain mesh. the gears wanna walk away from ea. other, the pre load pin keeps them in mesh, or a solid boss or the likes keeps them in mesh. this must be an improvement. if i'm incorrect, one your you marine techs please let me (us) in on the facts.

another improvement would be the lack of an oring groove in the lower drive shaft, just below the spines. apparently the o ring wasn't necessary + when the groove is present it creates a weak spot on the drive shaft. a strike with a solid object may break the prop or it may break the drive shaft, right at the groove. w/o the groove, the drive shaft would be less likely to break. let the prop take the strike.

both these improvements i believe to be in the lower. i don't know of any in the upper. don't mean there isn't though.
i recon (surely) there's more but them are some that i 'think' i'm aware of...