Upper Alpha one Gen 2 Replacement

[Rlwelch90]

Recently destroyed my upper Alpha 1 Gen 2 1.81ratio on my 93 Manta Ray. I believe it was the original apparently had some slack in it and jumped a tooth or something. Anyways it’s gone. So I ordered a used one off eBay. I know should have went SEI but I didn’t so I’m here now. The upper I ordered was off a 2011 unknowing to me the driveshafts are different. I see two ways to fix this. 1. Change the shafts out. The u-joints look different so that may not even be an option. 2. Could I change the Gimble bearing to a 98 and up Gimble? Is this a reasonable solution? Or am I just screwed?

 

[dubs283]

For some reason I'm thinking the issue you're describing with driveshaft length/u joint style only affects bravo drives. Im thinking gen 2 alpha drives all have the same shaft length regardless of u joint style/gear ratio

Been a minute since I've had to focus on that situation, could be mistaken about the bravo only comment

 

[Rlwelch90]

For some reason I'm thinking the issue you're describing with driveshaft length/u joint style only affects bravo drives. Im thinking gen 2 alpha drives all have the same shaft length regardless of u joint style/gear ratio

Been a minute since I've had to focus on that situation, could be mistaken about the bravo only comment

The length seems to be the same. It is actually the diameter of it. My original is labeled C and the “new” one is labeled D. I tried to install it and it would not go in. Splines were lined up because I verified by spinning the motor by hand and the splines turned with it.

 

[dubs283]

The stamped C and D represent the oem ratio of the drive. Based on the serial number of the drives you can verify with an oem manual the ratio. This is of course considering no one has changed the driveshaft(s)

Have you measured the diameter of each shaft and compared?

 

[Rlwelch90]

Visually they definitely look different. I haven’t actually measured so I will do that tomorrow. The “new” one visually looks bigger. It doesn’t taper off as slow as my old one. Good information on the stamped letters tho. Thank you for that.

 

[dubs283]

If you can still read them post the serial numbers of both drives and some pictures.

 

[Rlwelch90]

If you can still read them post the serial numbers of both drives and some pictures.

Old unit is- 00663273
New unit is- 1A292940
Old is without the top.

 

[alldodge]

The length seems to be the same. It is actually the diameter of it. My original is labeled C and the “new” one is labeled D. I tried to install it and it would not go in. Splines were lined up because I verified by spinning the motor by hand and the splines turned with it.

Merc hasn't changed the coupler splines from Gen 1 thru Gen 2. The shaft is a bit larger and uses a O ring to make a better contact with the gimbal bearing. Bearings also have not changed other then greasable and sealed

My guess is the motor needs to be aligned. Do you have a alignment bar? If not need to get one

 

[nola mike]

Merc hasn't changed the coupler splines from Gen 1 thru Gen 2. The shaft is a bit larger and uses a O ring to make a better contact with the gimbal bearing. Bearings also have not changed other then greasable and sealed

My guess is the motor needs to be aligned. Do you have a alignment bar? If not need to get one

Ujoints are also different in the pics--new one has internal clips. Wonder if the knuckle/input shaft is different to accommodate? If I wasn't on the phone I'd compare some part numbers...

 

[Rlwelch90]

Ujoints are also different in the pics--new one has internal clips. Wonder if the knuckle/input shaft is different to accommodate? If I wasn't on the phone I'd compare some part numbers...

I noticed the same. Knuckle definitely looks beefier.

 

[Rlwelch90]

Ujoints are also different in the pics--new one has internal clips. Wonder if the knuckle/input shaft is different to accommodate? If I wasn't on the phone I'd compare some part numbers...

Merc hasn't changed the coupler splines from Gen 1 thru Gen 2. The shaft is a bit larger and uses a O ring to make a better contact with the gimbal bearing. Bearings also have not changed other then greasable and sealed

My guess is the motor needs to be aligned. Do you have an alignment bar? If not need to get one

Thanks for that information. I have the alignment tool and aligned it yesterday when I was trying to stab the upper yesterday. I will re do it today.

 

[Scott06]

Could I change the Gimble bearing to a 98 and up Gimble? Is this a reasonable solution? Or am I just screwed?

I suspect this is what you need to do
the earlier drive has a gimbal bearing part number of 30-879194A02, newer drive is 30-862540A3

no idea if gimbal housing is diff size where bearing sits...

 

[Bondo]

I suspect this is what you need to do
the earlier drive has a gimbal bearing part number of 30-879194A02, newer drive is 30-862540A3

no idea if gimbal housing is diff size where bearing sits...

Ayuh,..... Welcome Aboard,...... Measure it,..... I believe they're the same,.....

I'm thinkin' it's bad alignment,..... or poor technique,....
Sometimes the double cardan joints wobble the wrong way, 'n it's a fight,....

The shafts appear to be the same, where it matters,.....
One has an o-ring to help hold grease in the coupler, 'n one don't,....
They both have o-rings for the gimbel bearing,....

 

[Rlwelch90]

Alignment and some persuasion and it finally went in there. Thanks for all the help y’all!