Mercruiser Alpha One, R and MR Serial Numbers 6225577 THRU 0D469858
Driveshaft Housing and Driveshaft
Insist on ONLY Original Factory Parts
The Upper Driveshaft Housing Assembly contains the two upper gears which determine the drive ratio.
before ordering parts for your Upper Driveshaft Housing Assembly there are a few things that you should know.
1. Not all upper gears and bearings are the same. You need to I.D. your drive and ratio. 2. Thin shims are used behind the bearing races to get the proper gear and bearing clearances. 3.Special tools are required to rebuild or reseal an Upper Driveshaft Housing Assembly. 4. There are fine measurements which must be adhered to and you will need a good micrometer, small torque wrench (0-30 inch)
and standard torque wrench (20-150 lb). 5. You will need a Shop Manual. 6. You will need a clean workbench and working area. 7. You will need a parts washer and a hydraulic press. 8. You will need a way to pressure test the unit to 15 PSI when complete.
If you are not willing to invest in the tools required to build an Upper Driveshaft Housing then don't do it.
Even with the special tools building an upper drive is a challenge.
Every clearance, every bearing, every shim and every seal must be installed exactly to specification or the drive will fail.
We can review your failure.
Do a partial or complete disassembly (where possible), clean the parts and perform an inspection.
Take a few photos of the failed components and email them to us.
Our advice is free and it might save you money and aggravation.
Know your options.