Hi lift tranny bearing question

[vipornstar]

Can anyone tell me why in step #2 of the HI lift Hilux Toyota manual it says NOT to replace the metal bushings with ball bearings in part J7. In the Hi Lift F-350 it says that ball bearings are an upgrade option that should be used. Do the ball bearings cause difficulty shifting?

[Mouton]

Ball bearings do not cause any difficulties shifting. They only reason I can see for not using bearings there would be that common bushings should be easier to glue in place (as it does not matter if you get some glue on the sides of them). If you are somewhat cautious when doing it I would recommend ball bearings.

Glue them one at a time and make sure the bearings move smoothly when the glue sets so you do not glue the bearing itsellf fixed. I see no reason for not using ball bearings there.

As a side note, I recently opened up my gearbox after 1+ year of intensive use. It had started to sound like a rock grinding mill. I thought the gears were worn down or that a bearing had seized. The only thing that had happened was that all grease had been washed away by water since the car has been wading a lot! :LOL:

[Suprachrgd82]

Like the masses, Supra blindly used bearings everywhere.

:thinking:
Supra theorizes that Tamiya insists that the reason not to use bearings is that the particular assembly in question slides on the shaft, and well as rotates. There may be a few reasons behind this.

Bearings, being hardened steel, while sliding on the shaft may not allow the assembly to slide as freely as would the bronze bushings. Bronze is much softer, and has lubricative properties.

Ball bearings do fair well under torsional forces appied to the side. In the even that one fail, the result would be catastrophic. Bearings and bits would be tossed into all of the gears and the tranny would be badly damaged.

Gluing bearings improperly may seize them. Also, glue does not bond well to hardened steel or stainless. A seized bearing would obviously damage the shaft.

[vipornstar]

Well thanks for the replies guys. I went ahead and built it like the manual said. Maybe when I build the next one I will do full ball bearings