Rundquist Propeller Tools, Inc.
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Intro to Propeller Repair
Changing Propeller Pitch
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Hub Replacement
How a Pitch Block is Made
How to Pitch the Propeller
How a Propeller Works
Propeller Rake
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Propeller Welding

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Repair Facility Setup
Propeller Repair

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rundquist Propeller Tools, Inc.

Hub Replacement

When replacing spun hubs, care should be taken to prevent injury, as a great deal of pressure is necessary to perform this operation.

Equipment Required

  1. A hydraulic press rated at ten (10) tons or better.
  2. The proper installation funnels, drivers and propeller supports.

Lubricants

Several Lubricants will work, you may use any one of these listed below.

  1. P-80 Rubber Lube, supplied by McDurmon Distributing.
  2. McDurmon 6000 Hub Lube
  3. Propco P-100 Hub Lube
  4. Karo syrup
  5. Liquid dish soap and alchohol, mixed in 1:1 solution.

Whatever lubricant is used, it must be water soluble and should not have an oil base.

 

Suggestions to make installation easier

  1. Soak new hubs in hot water, approximately 180 degrees F for a few minuts. This does not harm the hub and will enable the hub to compress with less pressure.
  2. In cold weather, the prop itself should be soaked in warm water. This prevents cracking the hub bore under pressure.
  3. Any hub with a cast flange on top - bevel the rubber at a 45 degree angle 3/16". This helps prevent the rubber from pinching between the flange and hub bore during installation.
  4. Use our Rehubbing Alignment Fixture - This fixture allows alignment to be maintained throughout the procedure.

Steps in Replacing Rubber Hubs

First, determine if the hub needs to be replaced.
  1. Check for burnt or frayed rubber
  2. If the hub has a cast flange and the rubber is not visible, you will notice bright or worn areas on the hub or the hub bore.
  3. If you are not sure a hub has spun - center punch the hub and the hub bore. Have your customer test the prop on his boat. If the (2) two center punch marks have moved, the hub is bad.
If it is determined that the hub is bad, use the following procedure to press the old hub out.
  1. Place the propeller on the correct funnel (measure hub bore to determine which insertion funnel to use). Use the correct hub driver to push the old hub out of the propeller and into the funnel. If the rubber cannot be pushed out of the propeller, cut the rubber in several segments with a sharp wood chisel. This will make removal easier.
  2. Inspect the propeller bore for cracks or damage. If the bore is out of round, the propeller should be replaced - not the hub.
Now you are ready to press the new hub in. Be sure that the ram is flat and square with the press table. If the ram is not square with the table the hubs will go into the prop off center.
  1. Using the proper support under the propeller, select the correct insertion funnel and hub driver you will need. Coat the insertion funnel and hub with the lubricant and press into the propeller. You will know when the hub is installed correctly when you can rotate the insertion funnel.

Note: Do not press the hub into the propeller with the prop sitting on the diffuser ring or blade tips. Once the hub is installed, do not use the propeller for twenty four hours. All hub replacement should be done at the customers risk. Breakage of the propeller can occur and is usually caused by brittle metal or casting flaws.

Through the years hubs and propellers have been modified by the manufacturers. Changes such as decreasing the outside diameter of the hub bore to allow for better exhaust and manufacturing the hubs using a harder rubber to prevent slippage. A hub is not a slip clutch. Its only purpose is to absorb shock to the drive train when shifting.

List of Corresponding Insertion Funnels and Hub Drivers

As styles change and new items are available, Rundquist will tool up and provide additional insertion funnels and hub drivers.

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Rundquist Propeller Tools, Inc. | Naples, FL 34104