Evinrude RX-4 Propeller and TBX Hub Kits
Posted: Sat Sep 10, 2016 12:22 pm
With the introduction of the Evinrude 74-degree V6 3.441-liter or G2 E-TEC engine, Evinrude also introduced a new line of four-blade stainless steel propellers, called the RX-4. The RX-4 features an adjustable venting system or variable vent port, shown below:
The RX-4 has an exhaust gas outlet with valve regulator at the base of the blades on the propeller hub. The valve allows exhaust gas to escape from the hub and bleed aerated water onto the blades at low speeds. As far as I know, this is the first propeller to have a built-in adjustable valve for this function.
Also seen above is the rather complex and swept back shape of the blades. And the exhaust hub snout continues somewhat longer than most propellers, then gently flares at the opening.
The RX-4 is available in pitches of 16, 18, 20, 22, 24, 25, and 26-pitch, and most pitches are available in both right-hand (standard) and left-hand (counter-rotation) orientation. All RX-4 propellers have a 15-inch diameter. The part numbers for them are as follows:
RX-4 RIGHT-HAND or Standard Rotation
Pitch / Part Number
16 = 177340
18 = 177320
20 = 177322
22 = 177324
24 = 177326
25 = 177328
26 = 177330
RX-4 LEFT-HAND or Counter Rotation
Pitch / Part Number
16 = 177341
18 = 177321
20 = 177323
22 = 177325
24 = 177327
The RX-4 propellers use the Evinrude Torsion Bushing eXtreme or TBX hub kit, which uses a plastic field-replaceable torque bushing, as shown below:
Part numbers for the TBX bushing or hub kit are as follows:
767683 = For production-year 2015 and newer E-TEC G2
177283 = For all Evinrude V6 engines through 2015 including G1 E-TEC
177288 = For non-Evinrude V6 engines from competitors
Evinrude has patented their invention of an "Axial Twist Propeller Hub" under United States Patent 6383042, which can be retrieved from
http://pdfpiw.uspto.gov/.piw?Docid=06383042&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D6383042.PN.%2526OS%3DPN%2F6383042%2526RS%3DPN%2F6383042l&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page
The invention shown in the patent linked above appears to be extremely similar to the TBX bushing or hub kit, as can be seen from this drawing from the patent (to which I have added text callouts instead of numbered callouts):
One of the claims made in the patent is that the patented invention provides for a "limp home mode" of coupling between the propeller shaft and the propeller that will continue to allow operation even if the propeller has struck some underwater object and the plastic coupling has yielded as intended. Details of this are given in the text of the patent. The patent was issued in 2002. I believe that the first time the TBX hub kit was available was c.2007.
The RX-4 has an exhaust gas outlet with valve regulator at the base of the blades on the propeller hub. The valve allows exhaust gas to escape from the hub and bleed aerated water onto the blades at low speeds. As far as I know, this is the first propeller to have a built-in adjustable valve for this function.
Also seen above is the rather complex and swept back shape of the blades. And the exhaust hub snout continues somewhat longer than most propellers, then gently flares at the opening.
The RX-4 is available in pitches of 16, 18, 20, 22, 24, 25, and 26-pitch, and most pitches are available in both right-hand (standard) and left-hand (counter-rotation) orientation. All RX-4 propellers have a 15-inch diameter. The part numbers for them are as follows:
RX-4 RIGHT-HAND or Standard Rotation
Pitch / Part Number
16 = 177340
18 = 177320
20 = 177322
22 = 177324
24 = 177326
25 = 177328
26 = 177330
RX-4 LEFT-HAND or Counter Rotation
Pitch / Part Number
16 = 177341
18 = 177321
20 = 177323
22 = 177325
24 = 177327
The RX-4 propellers use the Evinrude Torsion Bushing eXtreme or TBX hub kit, which uses a plastic field-replaceable torque bushing, as shown below:
Part numbers for the TBX bushing or hub kit are as follows:
767683 = For production-year 2015 and newer E-TEC G2
177283 = For all Evinrude V6 engines through 2015 including G1 E-TEC
177288 = For non-Evinrude V6 engines from competitors
Evinrude has patented their invention of an "Axial Twist Propeller Hub" under United States Patent 6383042, which can be retrieved from
http://pdfpiw.uspto.gov/.piw?Docid=06383042&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D6383042.PN.%2526OS%3DPN%2F6383042%2526RS%3DPN%2F6383042l&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page
The invention shown in the patent linked above appears to be extremely similar to the TBX bushing or hub kit, as can be seen from this drawing from the patent (to which I have added text callouts instead of numbered callouts):
One of the claims made in the patent is that the patented invention provides for a "limp home mode" of coupling between the propeller shaft and the propeller that will continue to allow operation even if the propeller has struck some underwater object and the plastic coupling has yielded as intended. Details of this are given in the text of the patent. The patent was issued in 2002. I believe that the first time the TBX hub kit was available was c.2007.