PSS Clearance Issues Part 2

After last week's disappointing PSS shaft install I went back to the drawing board thinking that I may have to purchase a different type of shaft seal system, but spent quite a bit of time online posting questions to both the Niagara and Westerbeke Owner's groups on Facebook.  Many Niagara owners had tight fits as well, but made them work.  I can only think that the engine beds in my Niagara were placed a bit forward of where others were, but that's just speculation.  I don't believe the original shaft seal was a PSS or if it was it was an early model that didn't use a vent and made it quite a bit shorter.  

Several people suggested taking the rotor to a machine shop and trimming it down to fit and I started to seriously consider this as an option but decided to call PSS and see if that was a possibility.  I'm glad I did.  It wasn't a surprise that they did not recommend doing that (although they never told me why), but they did say that they have a 'slow speed' stator (the carbon part where the vent normally comes out) that doesn't have a vent and is 3/4" shorter.  The only difference between the 2 is that the slow speed stator needs to be burped from time to time (when you launch for instance) to get the air trapped in the shaft seal out. 

I decided to take a chance on this route and was pleased that PSS said I could send the original stator back and they wouldn't charge me for the new one (except for shipping).  So I pulled the trigger on it and waited for it to ship from Washington state to New Hampshire.  In the meantime, I prepped the area by once again removing the transmission (I lost count after 8 removal/reinstalls) and the PSS.  Just to be sure, I put the transmission back on and checked the shaft alignment without any shaft seal in place.  

The new part finally arrived yesterday and I got to work as soon as it came.  I swapped out the original

New vs Old stators

vented stator with the new slow speed version on the nitrile bellows and installed it on the shaft log. Then I lubed up the rotor with dish soap and slid it onto the shaft up to the bellows.  Then I reinstalled the transmission yet again and installed the IsoFlex GearGuard drive saver on the transmission flange followed by the split shaft coupler.  I had previously painted the coupler with 2 coats of primer and 2 coats of black enamel to keep the rust down.  

With everything in place, I reached down under the transmission and compressed the rotor against the bellows the recommended 3/4" and set the grub screws on the rotor.  Because the access is terrible underneath the transmission, the only way to tell if the clearance is good is to stick a camera down there and take a photo.  I was happy to find that I now had about 3/8" clearance from the bottom of the transmission and I think that it acceptable.  If the shaft wobbles that much then I probably have bigger problems than it hitting the bottom of the transmission. 

I finished up by setting 2 additional grub screws in each of the rotor set screw holes to hold the first ones in place (with blue loctite) and torqued the IsoFlex and shaft coupler to spec.  Once completed, the shaft spun nicely with the transmission in neutral with no 'hard' spots along the rotation.  Just to make sure I could call it complete, I dry installed the MaxProp hub on the outside to make sure I had the proper clearances (I did).  

I really never thought that this job would take soo long to complete, hopefully the other engine install jobs which are up next won't be quite as taxing (raw water, electrical, controls, fuel).