Tamiya 3 Speed..... Love It or Hate It?

[Claus]

I think we can all agree the Tamiya 3 Speed Transmission is
1)Bulky
2)Sloppy
3)Too Fast (without the use of a gear reduction)
4)Not AWD Without a Separate Transfer Case
5)Plastic Gears, Synchronizers, Transmission Case

but it's also
1)Indestructible (for the most part)
2)Bolts in Easy to a Tamiya Chassis
3)Can Easily add a Gear Reduction to it
4)Has Several Pinion Gear Options
5)Metal Gear Upgrade Available (along with synchronizers and transmission case)

So do you love it or hate it? I'm a fence straddler!

[Cossett]

You forgot to add in the good part - you can also lock the gear box with the black plastic stops that go on the outside of the gear selector rod on the ends of it.

I like it to but after a while the 3 speed just becomes a gimmick and its just as easy having it in one gear and ajusting the throttle with your thumb/s

But like the rest of the drive train the box was made to last as long as your servo settings are correct and your not constantly grinding gears//

Cheers Tracy

[buff69]

Hi where can I get the metal parts (gears) and how do you do a gear reduction also which electric motor to use Sorry I'm new to this and can't make my mind up on a Scania R620 or the merc Actros 6x4 many thanks ��

[Claus]

There are many types of gear reductions. Lots of guys here use one from RC4WD, there is also a Great Planes gearbox that can be used as well as a couple different kinds from garden trucking.com
http://www.tracgear.com/product/rc4wd/custom/gru/v1/1.jpg
http://www.tracgear.com/product/rc4wd/custom/gru/ultra/2.jpg
http://www.gardentrucking.com/pix/Originals/t1225.jpg
http://www.gardentrucking.com/pix/Originals/T1204a.JPG
http://www.gardentrucking.com/pix/Originals/1204t.jpg

[sparkycuda]

Stock Tamiya trans can be modified with a longer shaft to make it AWD. Got mine from Semi Joe a couple of years ago. I used a RC4WD reduction unit between it and the motor. Works great.

Ken

[Claus]

Stock Tamiya trans can be modified with a longer shaft to make it AWD. Got mine from Semi Joe a couple of years ago. I used a RC4WD reduction unit between it and the motor. Works great.

Ken


Just asked Him about those a couple days ago, He told me He had 150 made, all sold out and not making anymore.

[Claus]

Hi where can I get the metal parts (gears) and how do you do a gear reduction also which electric motor to use Sorry I'm new to this and can't make my mind up on a Scania R620 or the merc Actros 6x4 many thanks ��


These pictures are borrowed off of this forum of how a Great Planes gearbox can be used before or after the transmission with some work.

http://img.photobucket.com/albums/v492/monsterbeetleguy/GD600%20Install/gd600006.jpg
http://img.photobucket.com/albums/v492/monsterbeetleguy/GD600%20Install/gd600005.jpg
http://i58.photobucket.com/albums/g276/theonlytamiyacowboy/IM003416.jpg
http://i58.photobucket.com/albums/g276/theonlytamiyacowboy/IM003415.jpg

[mrgrimm]

I like the 3 speed so far. I bought a used 6x6 and it has the shaft mod, just gotta make sure the trans is mounted pretty low to keep a good driveline angle. I also just completed building a stock King Hauler and that tranny has been doing just fine as well.

It is kind of a pain to have to remove the whole setup to take apart the case for a motor change though.

[Radio Control Trucker]

I agree with Tracy. I prefer to lock my 3-speed tranny into 1st gear.
With an overall speed of nearly 35mph, it's just a little too fast for the trucks if you ask me.

- RCT

[Claus]

I forget now, does anybody know the ratios of a Tamiya 3 speed?

[Cossett]

Here you go Claus -
1st - 1.32.49
2nd - 1.17.66
3rd - 1.10.66
With the stock motor and pinion
But that will change if you use after market pinions and motors

Cheers Tracy

[Cre8rc]

I'm not a fan of the 3spd, way to fast for my liking.... I am going to install a gear reduction unit on my Rig and lock it in 1st gear. To me that is way more scale and controlable.

[schmoking]

with a 4:1 reduction im loving the 3 speed, and i use all of them.
no more melting the esc when im hauling the excavator.

[bigpipespete]

I for one hate it.

[Bo Wallen]

I like it a lot........and i say no more........or i do.......let's figure this bugger out. I'm going to show a few different set-ups at Cabin Fever in mid January. After that someone might catch that on a youtube or not. Conclusion is however coming in this forum. To be or not to be.......gearbox or kill it. :cop:

[Cossett]

I just find replacing the 3 speed easier a matching planetry and motor better as it takes up less space, and you can still run a MFU...

Cheers Tracy

[Rimrock]

I find it a bit wired to explain someone new to the hobby that the 'original motor and transmission in this fine scale model is prepared for truck racing competitions, for unknown reasons, but if driving the truck as a real truck hauling goods you have to put in xx-xxx USD additional to upgrade this xxx USD kit. Sorry.' But the 3 speed transmission looks great as a picture on the box, I must admit)

[markturbo]

When I first started looking at the Tamiya Semi's the 3 speed was part of the cool factor of these trucks. Now that I own one I still think they are cool but they are a bit too fast. Does anyone have a picture of one with a gear reduction mounted at the motor, I've been looking at the one rcmart sells.

[Cossett]

When I first started looking at the Tamiya Semi's the 3 speed was part of the cool factor of these trucks. Now that I own one I still think they are cool but they are a bit too fast. Does anyone have a picture of one with a gear reduction mounted at the motor, I've been looking at the one rcmart sells.

Have a look at the carson poison motors ( got then in my two knight haulers ) or similar turn motors like rock crawlers use

Cheers Tracy

[markturbo]

I'll take a look at those. I did try the Tamiya Semi Truck Torque tuned motor and that did slow it down a little, then I tried an RC4WD 45T I think it was but it's like the truck didn't have as much torque which was odd.

[bigford]

Stock motor and a pmd 4:1 pulls like a tractor should

[Northern Farmer]

Stock motor and a pmd 4:1 pulls like a tractor should

Couldn’t agree more. The PMD 4:1 is a must have with the Tamiya 3 speed :cool:

[markturbo]

What's the pmd 4:1 ?

[bigford]

Its a 4:1 gear reduction unit that bolts to the back of
The tamiya 3 speed

[markturbo]

Ahhhhhh ok. I'd need a motor mounted reduction as I modded my 3 speed for an output Shaft on the front as well.

[bigford]

I have the Rc4wd gru unit in this truck.
It's louder then the pmd one for sure
https://youtu.be/DQur5UcZZSg

[markturbo]

Wow, 90 pound load? Was that in first gear at full throttle?

[skeeter]

Ahhhhhh ok. I'd need a motor mounted reduction as I modded my 3 speed for an output Shaft on the front as well.

Do you have photo's of this conversion process? Perhaps you could do a tutorial video for the rest of us to follow? I've seen it posted on SemiJoe's FB page where he converted one, WITHOUT using the "SPECIALLY" made shafts that he once had made. After seeing the pics, & reading about it, I'm still a bit confused of how it's done. I wish there was a video showing the process!

[markturbo]

I saw Joes method too and im unclear as well. All I did with mine was extend the length of the output shaft by building the end up with a mig welder, then shaped it on a bench grinder. A bit hard to see in this pic as its in front of the shift rod.

https://i.imgur.com/ibcSeNqh.jpg

[Lmackattack]

I like the 3 speed but it is very bulky and top gear is way to fast for anything other than empty parking lots and that can lead to a costly roll over. the 4:1 by PMD makes the stock 3 speed much better if you have the space to mount it. Out of the 4 trucks I have only 1 has the 3 speed in it and I used a slow RPM motor with it to keep speed down in 3rd gear. Its a cab over carpet queen with the room for it and tt sees no off road use so I dont mind keeping it. As for the other 3 trucks that pull weight around I found the RC4wd planetary disruptor is geared to about the same 1st gear ratio of the tamiya 3 speed. It does everything I want with around a 35T motor. It has the torque to pull the front axle off the ground on a good hard pull and the slow speed control for the off road. I think the biggest plus with the disruptor is I can mount the unit and motor in a compact space on the lower flange of the frame rails and none of it sticks above the top of the frame rails. this makes mounting stuff under the hood and cab of a day cab tractor very easy.

thats my .02

[Tommy R]

For those who've modified a Tamiya 3 speed for a front output. How much did you lower the trans to get a decent driveline angle for the front shaft? Or did you significantly lower the truck to bring the front axle up? Thanks!