44xs lower unit help please.

[Glenno]

Hi all,

I am just wondering what steel you are suposed to use for the pin through the gear on the prop shaft into the prop shaft under the main prop shaft bearing??? 44xs 1 to 1 drive lower unit. I have pressed the new gear on the new prop shaft with the pin holes lined up sweet but dont want to proceed untill I can sort this pin.

Any help would be really apreciated as I was hoping to use the old pin but it is truely stuck in the old shaft and broken gear.

Thanks heaps
Glenno

[foot_doctor]

I've been using BRP (OMC) Monel drive pins that start out at 3/16" diameter. I turn them to .180" and cut to .010" shorter than the hole depth. They drop in, then I press the shaft slightly further into the gear to limit the possibility of the gear getting a running start on shearing off the pin. R.T.

[ZUL8TR]

gear pins

The 20H and early 25ss list the gear pin PN as 17-20937 and the 25xs, 44xs, 30H and 55H list PN 17-813061. What is the difference?

[Guest]

Gear drive pin

At times I have not had the Mercury prop gear drive pin to install after disassembly of a lower unit. What I have found to work very well for me is a cut off pin made from a good quality drill bit. I use a Dramil with a fine cutoff wheel to keep the heat down. After cutting cool it with water. The easy way to get the size you need is to use a drill set to establish the diameter and the buy a new bit. Most times you can get four or so parts from one bit. These make a good hard pin which is also tough for you drive gear installation.

Alan

[foot_doctor]

All of the Quicksilver gear cases that use the 9/16" prop. shaft use the short pin. The 11/16" prop. shafts use the longer one. R.T.

[modhydro]

Gear pin

All that I have ever used is a 3/16 aircraft clevis pin. Harry Brinkman put me on to that years ago. I can't even tell you how many I have done for people with that method and none have every come back with an issue from it.

If you can drill all the way through the other side and run it in double shear as well.

Steve Roskowski

[Dave M]

Drill Bit

At times I have not had the Mercury prop gear drive pin to install after disassembly of a lower unit. What I have found to work very well for me is a cut off pin made from a good quality drill bit. I use a Dramil with a fine cutoff wheel to keep the heat down. After cutting cool it with water. The easy way to get the size you need is to use a drill set to establish the diameter and the buy a new bit. Most times you can get four or so parts from one bit. These make a good hard pin which is also tough for you drive gear installation.

Alan

If you can't get your hands on the original Merc part number, I agree with Alan. I have used drill bits cut off for years and not had any issues.

I am talking pinning the gears, not a shear pin. You are talking of pinning the gear, right ?

[foot_doctor]

MODHYDRO is absolutely correct. Aircraft grade clevis pins have an incredibly high shear strength, yet they are still not so hard that they shatter easily. I would certainly use them if I had not inherited a large quantity of the Monel pins from my Dad who used to work for OMC Research. R.T.

[modhydro]

Pins

I did forget to mention that you don't want to get them hot when you are cutting them to length or you can anneal them and make them too soft.

Steve

[Glenno]

44xs gear case help

Hi all,

Just posting a big thanks to David and Alan from Aeroliner boats for all there help regarding parts and info for the rebuild of my 44xs lower unit. Thanks also to Frank for suplying the new gears. Thanks for everyone else who has given information aswell.

The lower unit was a bit of a challenge for me to rebuild. The caged roller bearing in the nose of the foot was a bit of a challenge to remove. After fabricating about 4 special tools to do varios things regarding the rebuild I am more confident.

Took the boat out yesterday and she has never gone that fast, looks like the old gears and old lash setting was so bad that the gears where causing so much friction that is was slowing the motor.

Thanks again
Glenno

[A/B Speedliner]

It was our pleasure

Glad we could help, it was and is our intention to do what we can to keep these old warriors going for as long as we can.

David and Alan van Weele
Aeroliner Race Boats, LLC