Jeff R

Jeff R

Well Known Member
I have an IO-320 with a fixed, metal Sensenich prop. I was trying to fit it today to the engine to do some fittings, but I cannot get the prop extension to mate fully with the properller. Even with some lubricant and gentle tapping with a rubber mallet, I can't get the guide pins into the prop holes. Before I start tapping harder I thought I would check to make sure this is indeed a very tight fit that takes a LOT of tapping with a mallet.

Thanks.
 
Mount the extension and the prop to the engine. Use all of the prop bolts. Tighten with your fingers then start tightening with a wrench. Go from one bolt next to a pin tighten a little bit then go to the opposite side and tighten a little then work the other bolts till just tight then repeat the process till all the bolts are tight, no need to torque at this time. Make sure you have the spinner back plate in place when you do this as once the spacer is on it is very difficult to take off.
 
RTM...

Jeff R said:
I have an IO-320 with a fixed, metal Sensenich prop. I was trying to fit it today to the engine to do some fittings, but I cannot get the prop extension to mate fully with the properller. Even with some lubricant and gentle tapping with a rubber mallet, I can't get the guide pins into the prop holes. Before I start tapping harder I thought I would check to make sure this is indeed a very tight fit that takes a LOT of tapping with a mallet.

Thanks.
Click to expand...

Check the Sensenich installation instructions.

http://www.sensenich.com/misc/mpinstal.htm

They specify a 5 pound hammer, so it's not surprising that your rubber mallet didn't really work...:)

They are not kidding with this sentence in the instructions.....

NOTE: THE PINS ARE VERY TIGHT (BY DESIGN) AND IT WILL TAKE SEVERAL HITS TO ATTACH THE SPACER
 
Norman CYYJ said:
Mount the extension and the prop to the engine. Use all of the prop bolts. Tighten with your fingers then start tightening with a wrench. Go from one bolt next to a pin tighten a little bit then go to the opposite side and tighten a little then work the other bolts till just tight then repeat the process till all the bolts are tight, no need to torque at this time. Make sure you have the spinner back plate in place when you do this as once the spacer is on it is very difficult to take off.
Click to expand...

Don't do this! ^^^^

az_gila said:
Check the Sensenich installation instructions.

http://www.sensenich.com/misc/mpinstal.htm

They specify a 5 pound hammer, so it's not surprising that your rubber mallet didn't really work...:)

They are not kidding with this sentence in the instructions.....

NOTE: THE PINS ARE VERY TIGHT (BY DESIGN) AND IT WILL TAKE SEVERAL HITS TO ATTACH THE SPACER
Click to expand...

Yup!
Use Gil's link and follow the instructions that are typically supplied in the box with the new propeller.
As implied, it fits very tight. Using the bolts to pull the prop on to the pins risks damaging them or the crank flange bushings.
 
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Prop fit

I had the same problem and fears. Talked to Ed at Sensenich and advised to either put prop and extension in press or take a 2x4 place it over the extension, support the prop so hub doesn't get scratched up and beat the h*** out of 2x4 alternating between the pins till it's snug against the prop hub. To remove the extension place prop blades on some 2x10 and using a drift drive the pins out with a HEAVY hammer, again alternating between the pins for even removal or insertion. The steel pins actually remove aluminum from the prop hub-this is normal. Unnerving but this is how it is done at the plant. Place blanket or something under hub to catch extension when it falls out.
Mike H 9A/8A
 
Well, I did it today and it took a lot of blows but it did go in. I used just an ordinary carpenters hammer and a block of eak. It is a bit unnerving to get out the ole hammer to bang something into place on a precision-built airplane, but it went on fine.
 
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