prop shaft packing

[dpiano]

Is there a common agreement about how often the packing needs to be replaced on the prop shaft, and what material to use? Our R29 is 5 years old, 1000 hrs on the engine. I have adjusted it maybe once/year as needed, but I am having to crank down harder than I used to, to get the correct drip rate. Andrew sent me to Marine Hardware to get the correct material (kevlar 1/4” square) but I’ve seen on youtube a suggestion to use a graphite material and lubricant called syntef. Then saw comments saying don’t use syntef because it blocks dripping and can cause heating.
I’d appreciate your thoughts

 

[sabadd2003]

I just did my 25 classic from what I learned from marinehowto.co. He explains your question very good.

 

[knotflying]

Go with what was recommended by Andrew. I got about 1,200 hours on my original packing so you are within range. I found that you can find a piece of PVC pipe the same diameter as the shaft and you can pre-cut your packing on a bias and it makes it much easier. Another trick (thanks Gansett Ranger) is to get another piece of PVC pipe that will go over your shaft and cut it in half and slightly longer than the packing nut. You can then place the packing in one piece at a time and either tap it in by hitting the PVC against the packing or squeeze it in using channel locks with one jaw on the back of the nut and the other on the PVC sleeve.

 

[dpiano]

Thanks for the suggestions. I have the 1/4" kevlar packing now, and the PVC pipe is a great idea. Marine Hardware did not recommend Syntef lubricant, said it is not necessary. I've heard some people change the packing while the boat is in the water, but not on my watch! Boat has to come out on the trailer to change anodes anyway. Glad to know that 1000 hrs is not out of line to need new packing.