Finally the first PSRU with a reduction of 3.12 to 1. Pictured is the basic box which is heavily based on Tracy’s PSRU but with the larger reduction and 2 oil lubricated thrust bearings on the prop shaft instead of a single sealed roller bearing in Tracy’s. This psru will mount directly in place of Tracy's 2.85 reduction PSRU with no modification.
Now to put to test to see if the practice matches the theory. Already found one fault. The “O” ring seal that seals the main body of the PSRU to the base that attaches to the mounting plate is outside all the attachment bolts, which means that the oil can wick down the bolts and make a lovely mess of your pride and joy. Now looking for more faults as this is easily fixed. Unlike Tracy's , this PSRU is totally sealed with O rings to ease dismantling with no clean up of whatever gasket sealer you have had to use.
Now the terrible part and still undecided as I am yet to cost a damper on the drive. Sadly it also is not cheap and may yet cost near $500 for a ”bit of rubber”. Then comes a mounting plate as made by Geoff Doddridge which he sells for around $400 USD. There is no point in me trying to compete with Geoff as he does a magnificent job at a cheap price. Freight is always a horrible price so he makes the plate and there is no freight from Aust to be added.
The total cost in Aust dollars (including Geoff’s plate) will be around the $5000 which equates to $3500 USD. Then freight of possibly $200. Currently looking at further reduction in price if you source the gear set locally saving on freight both ways to Aust and back. I will have to alter the way it is constructed so that all the mods can be done by you the builder. Still looking!
So far the progress. Neil.