Original Bruiser transmission ratios

[Saito2]

Does anybody know the original Bruiser's transmission ratios? Tamiya USA list the re-release versions as 1:54.63 in 1st/4wd, 1:40.49 in 2nd/2Low and 1:27.92 in 3rd/2High. Did Tamiya change the ratios for the new and revised transmission and if so what were the original ones? Thanks.

[WillyChang]

From https://www.tamiyaclub.com/forum/index.php?/topic/36810-hilux-3-speed-gear-ratios/&do=findComment&comment=222054

 

Quote

taken from the FAQ at 

http://www.rcmt.net this is for the bruiser, the tranny itself is the same, different spur and pinion in hilux/blazer though

First I removed the endbell of a motor and marked the armature for reference. I then counted how many turns of the motor it took to get 1 turn on the output shaft. Here is what I got.

Low speed (4x4) - 23:1

Med speed - 11:1

High speed - 5.5:1

I then took the tranny apart and counted teeth to see if my numbers above match the gearing in the tranny. Here is what I got.

52 tooth spur (plastic gear) with a 10 tooth motor pinion. This is the primary reduction and gives you high speed at 52/10 or 5.2:1 ratio. This matches my eyeball measurement above of 5.5:1. The second possible reduction is an 11 tooth gear turning a 23 tooth gear for a 2.09:1 reduction. 2.09 x 5.2 gives you a 10.87 reduction. This too matches my 11:1 eyeball estimate above. The third possible reduction gives you yet another 11 tooth to 23 tooth reduction or 2.09 x 10.87 for a 22.7 reduction. This too matches my eyeball observation of 23:1. So, to sum it up, the stock tranny's ratio's are:

1st gear (low speed, 4x4) - 22.7:1

2nd gear (med speed) - 10.87:1

3rd gear (high speed) - 5.2:1

Keith 

Quote from Dave engle

All of these setting are true if the transmission is stock.

Shifting rod pushed in to the transmission is third gear or "Top Gear." Two wheel drive.

Shifting rod in the middle position is "Second Gear." Two wheel drive.

Shifting rod pulled to the outter position is first gear or "Low gear." 4 wheel drive.

 

 

[Saito2]

Thanks! Wow, if the numbers Tamiya supplies are correct, Tamiya MASSIVELY geared the new transmission down in every ratio. I'm guessing this is to run the less torquey 540 motor in the new version opposed to the big 750 in the original. Every video I watched of the original Bruiser at speed looked far faster than the current day version.

[nde63h]

1 hour ago, Saito2 said:

Thanks! Wow, if the numbers Tamiya supplies are correct, Tamiya MASSIVELY geared the new transmission down in every ratio. I'm guessing this is to run the less torquey 540 motor in the new version opposed to the big 750 in the original. Every video I watched of the original Bruiser at speed looked far faster than the current day version.

not so certain. the original poster wrote "I then counted how many turns of the motor it took to get 1 turn on the output shaft". his counting ended at the output shaft. did he count the gear ratio between the bevel pinion gear and the diff gear?

[Saito2]

True. I don't know if the original poster or Tamiya USA are factoring in the axle ratio or not.

[GooneyBird]

On 25-2-2018 at 3:09 AM, Saito2 said:

True. I don't know if the original poster or Tamiya USA are factoring in the axle ratio or not.

I don't think so. He's looking at the output shaft (of the transmission) and the rotor inside the motor. This is before the output shaft hits the axles. So there's an additional reduction in the axles.

Which would make sense, considering that 3rd gear would otherwise be equivalent of what I'm running in the TRF419, 'cept the Bruiser is on tires that are easily 4x the circumference.

[Saito2]

So you think they're calculated from the same point? I guess my original supposition of massive gear reduction across the 3 ratios might be true. I remember seeing videos of the old Bruiser being faster than the then-new High Lift trucks but that's not the case with the re-re Bruiser.