Flo-Torq II Hub: Are there different thickness Forward Thrust Washers?

[kbeckman]

I picked up a used Mercury Mirage + prop, 48-18278A45. This uses the Flo-Torq II hub system. I installed it on a 1996 Alpha 1, Gen 2 drive. I used a new Flo-Torq II kit, which came with the Bronze Forward Thrust Washer (48-835467Q01). I can hear and feel the prop touching the case behind the prop. It's not touching by much, but it is touching. I tried a number of different 835467 washers, and they all rub. My old Aluminum prop is fine with the 835467 washers.

I found a stainless steel one stamped 77987, and it no longer rubs. I looked up the 77987, and it subs directly to the 835467, but one is Stainless and the other Bronze.

Am I harming anything by using this Stainless washer?

 

[Fun Times]

My first thought was maybe the plastic sleeve isn't seated all the way in/down. If it isn't seated, it may rub the gear housing. Just in case you may want to watch this video by forum member achris for possible installation tips, https://www.youtube.com/watch?v=ebWHIKRBKpQ

The forward thrust washer part number you had 48-835467Q01 but it should be 12-835467Q01 ?.

The 77987 in your photo should work just the same as that is an older part number of all the newer ones...12-835467-1 - 12-835467Q01 - 77987A1 , http://www.ebay.com/itm/NEW-Mercury-...-/170798119435

^ this could just be me but even though i never actually measured, I do tend to sort of recall just having the older silver type and later brass type in each hand, the silver one just seemed a bit more heavier duty with a thicker feel to it....You the same? Think Chris mentions a little something too regarding the two.

What type of boat are you going to run this Mirage + on an Alpha drive?
Just an fyi of why I asked what boat, depending on boat size, weight, design, etc., "sometimes" the Mirage + diameter can be just a bit lager than the diameter of the Alpha gear case in turn affecting certain performance aspects on some smaller performing boat hulls running an alpha as in a possibility that all the ranges that you are looking for might be there but at certain points the boat might feel just a little bit sluggish vs smaller diameter props....But if the boat is bigger, heavier more of a cruiser type boat, then the bigger diameter can be really be helpful.

 

[kbeckman]

You are right on the part # prefix, I didn't pay attention. The SS 77987 Thrust Washer does seem thicker, but I didn't measure it. The sleeve is seated, but wouldn't that have the opposite effect? It seems like the prop is in maybe .001" too far, and a poorly seated sleeve would push it out farther?

Boat is a 22' 1996 cabin cruiser, 5.7LX Mercruiser (Roller Cam crate motor, likely 270HP at 4800 RPM), 1.47 ratio Stern Alpha One, Gen 2. Boat is speced at 3480 lbs, but have never weighed it and I suspect it's heavier than this.

I switch between an Aluminum prop when I launch, to Stainless prop for the season. The ramp I use is shallow, and not really suited for the size of my boat, but it's close to where I keep it. There are rocks at the ramp, as I have taken out a couple props over the years.

The AL prop is a Mercury Typhoon TA2010X 16 x 16p. Un-trimmed I get 4700 RPM and 39.0 MPH. Trimmed 4950 RPM and 40.8 MPH. Doing the math that equates to a whopping 20% slip. The TA2010X has a rougher finish than the QA2010X and I wonder if that has anything to do with the slip.

With the 15 1/2 x 17p Mirage +, Un-trimmed I get 4210 RPM and 40.5 MPH. Trimmed 4400 RPM and 43.0 MPH, with only 10% slip.