Max Prop - shaft and hub tightness

Jan 9, 2020
55
J J/42 1 New Castle NH
I had my max prop classic reconditioned this winter and re-installing was fairly straightfoward. However, if I tighten the hub bolts more than hand snug, the blades are wicked stiff and don't open when rotating shaft. The prop is greased, and installed correctly I believe. Searched internet and not much info on how tight to make these bolts. The one thing I did notice is that there is 2-3 threads of shaft showing after I tighten the nut, and PSI says two is the max.. so wondering if that could be part of it? Or is it ok to just have the bolts snug tight on the hub and installed witht eh cotters properly?
Thanks in advance for any sage advice
Sean
 
Feb 26, 2011
1,428
Achilles SD-130 Alameda, CA
Two things could be going on here; either you have too much grease in the spinner halves/end cap or the prop was driven further up the shaft upon reinstallation than it previously had been, exposing enough threaded shaft end to to keep the cone gear from seating properly. The bolt tightness should have no affect on the prop's operation. I suggest removing the grease hole plug screws and rotating the prop back and forth to run as much grease out of prop as possible. If that doesn't do the trick, you can remove the end cap and check to see if the cone gear is properly seated. If it does not sit deeply into the spinner halves, you will have to cut more threads off of the shaft end. This was already done when the prop was first installed, so would lose nothing by removing more threads. If you do this, before disassembly be sure to feather the blades fore and aft and mark a spot on spinner halve and end cap so that you can return the prop to the same pitch setting.
 
Jan 9, 2020
55
J J/42 1 New Castle NH
So helpful--thanks! I bit more context.. as part of this project, I ended up with a new shaft made by a local shop, and they said they mated it to my prop (they had the hub), so it's very possible it's a tad too long on the threaded hub end (2-3 threads showing). I greased it per spec as well. I'll try cutting a thread length off the end and re-install. Now that I think about it, I can see how tightening the prop hub bolts down on the cone gear (if compressed against end of shaft) would create too much binding in the gears.
Thanks again!
Sean
 
Nov 6, 2017
76
Catalina 30 5611 Stratford, Ct
I would remove the prop from the shaft and assemble it on the bench. If the prop works without binding, I would have to say the shaft threads need to be trimmed. The company also has excellent customer support through email. On a side note, I just had my classic prop off to reset the pitch and found it very easy to put things in the wrong position. The part I put in wrong was the three-pin thing the blades slide onto. The numbers will not match the housing if you do that and I did have some binding because of that. Rotating that part will allow all the numbers to match.
 
Jan 9, 2020
55
J J/42 1 New Castle NH
Thanks.. thinking before I cut the shaft I'm going to back the nut off a turn or two and re-assemble to confirm. maybe I tightened the nut too much?
 
Jan 9, 2020
55
J J/42 1 New Castle NH
Just a quick update.. shaved off one thread from end of shaft and that fixed the binding problem. Thanks for the guidance.