Marc73

No taffer, I did not forget that the Tamiya publication supports exactly your theory :-) Thought you would like to see the original document and wanted to share it.

Interestingly, I found a publication from 1987, in which Tamiya recommends a normal ball bearing as an upgrade, so I might follow that recommendation in the future and replace the E1/thrust washer combo at the shafts of the propeller joints front and rear, but stick with the one piece thrust bearing (53136) at the end of the output shaft of the rear gearbox.

Thank you for your detailed reply, Nowinaminute! It is totally possible that the results I found in my experiment were due to molding flesh on bevel gears. However, I used my runner that had already a running time of several hours and not a new built gear. Since I don’t know how to remove molding flesh of bevel gears myself and since I have the shaft of the propeller joints on both sides supported by ball bearings, I will stick to the E1/thrust washer combo in both propeller joints front and rear. But, as you pointed out in your post, the third location where the E1/thrust washer combo is used is at the end of the output shaft of the rear gearbox. In this location, the shaft is not supported on both sides by ball bearings. Thus, I repeated my experiment with the rear gearbox by twisting the rear propeller joint and using the above mentioned 5 different setups at the end of the output shaft after tightening the 4 screws of the gearbox cover and thus applying axial pressure. This time, the outcome was totally different to the first experiment: The highest resistance was found using the E1/thrust washer combo and the three piece thrust bearings. The best options in this location with lowest resistance were the 5x11x4 steel ball bearing and the Tamiya 5x11x4 one piece thrust bearing (53136), with a slight advantage for the one piece thrust bearing. Based on this, I will use in my Thunder Shot full ball bearings, stick with the E1/thrust washer combo in the front and rear propeller joint and thanks to Nowinaminute now use the sexy looking Tamiya 5x11x4 one piece thrust bearing at the end of the output shaft of the rear gearbox (53136) :-) Cheers, Marc

Very interesting topic, didn’t even know there were options to replace the E1/thrust washer combo. Thus, I did a little experiment with 5 study groups and 3 outcomes. I took out the entire front gear and twistet the propeller joint to feel the resistance when turning the propeller joint. Study groups were: 1. E1/thrust washer combo 2. steel ball bearing 3. original Tamiya one piece thrust bearing 53136 5mm x 11 mm x 4 mm 4. three piece thrust bearing 5 mm x 11 mm x 4,5 mm 5. three piece thrust bearing 5 mm x 11 mm x 4 mm (similar to the one that was used as an upgrade in the 80s terra scorcher) Outcomes were: low resistance, medium resistance and high resistance. Results: 1. E1/thrust washer combo => low resistance 2. steel ball bearing => high resistance 3. original Tamiya one piece thrust bearing 53136 5mm x 11 mm x 4 mm => high resistance (surprising and disappointing since it looks really sexy :-) 4. three piece thrust bearing 5 mm x 11 mm x 4,5 mm => high resistance (not surprising since 0,5 mm too thick) 5. three piece thrust bearing 5 mm x 11 mm x 4 mm => medium resistance (surprising since closest to 80s upgrade) Conclusion: I will use E1/thrust washer combo only. Cheers, have a nice weekend!