Madcap/king Cab Gear Train

[matisse]

Hi,

as i understand it the madcap/astute/king cab/MR series share the same gear box, is it possible to add the super astute TTC gear train to these, and if so is it worth it?

I'm looking at adding in to a madcap and a king cab/MR if i can get hold of one.

thanks

matisse

[kontemax]

Yes,

you can use TTC on all these cars but keep in mind: TTC gears teeth are smaller so don't know if they live long with the heavy king cab.
Is better if you upgrade original tranny with some thorp hop up in my opinion.

Cheers

Max

[GTodd]

Modern off road cars survive all day long on 64p gears, so dont fear about using the TTC. But if you build the diff correctly and use extra shims to adjust the diff as recommended in the manuals of Astutes/King Cabs then that diff will last. I have never understood why people have complained about these gearboxes the diff in particular. I have owned and race all of tamiya's chassis that have had this design diff (Egress, Astute, and Monster Racer) and have never had a problem with it.

[kontemax]

I used all cars with these ball diffs and with 4wd ones no problems. Also no problems with Astute and Mad Cap ones.
With the King Cab I had a lot of problems cuse the diff cups.
I used a 18x1 turns motor with Monster Beetle tires.
All rear gearbox did became jam, more times. I broke plastic iddle gear mount (replaced with aluminum one) and the iddle gear also. Then I broke two times the second gear of the spur gear, with the iddle gear too. Then I broke the ball diff, grinding it 3 or 4 times, burning the balls and so on. I built my self the alloy diff housing, no more grinding but then I broke two times the iddle gear and the diff gear teeth.

The problem is that it needs a slippery. Then I built by myself a slippery and no more breakages.

TTC tranny: It works great but it needs a lot of manteniance cause the dust. I worn out the iddle and diff gear teeth, cause excessive wearing due the dust. I did often open the tranny and cleaned it.
I think this tranny on the King Cab will do a quickly bad end...

Kontemax

[terry.sc]

I have never understood why people have complained about these gearboxes the diff in particular. I have owned and race all of tamiya's chassis that have had this design diff (Egress, Astute, and Monster Racer) and have never had a problem with it.

Easy answer to this one. Most owners weren't racers, so when Tamiya said use grease they used whatever was available rather than ball diff grease designed for this purpose. Any other grease keeps the balls off the washers and so it slips.

The other reason is that most owners don't understand shimming, they build it with the washers Tamiya says you should fit in the manual and that's it. It can be fixed by adding an extra shim but that thought never happens and they go out and buy a new diff instead.

[kontemax]

Hi Terry,

I can also add that the King Cab/Astute diff housing were made with poor material (at difference with alloy ones on the Egress) and with work and heat they deforme leaving the balls to slip into the diff.
That diff was made to slip a little bit to prevent breakages but slipping and slipping with hot motors the housings lost their shape for the heat.
If you added shims you did solve the problems for some time, then it did come back agan until the end of your shims.
A true aloy housings should be the real solution and only then shimming should make their real job: adding or leaving softness to the diff. But Tamiya neved did the hop ups.

I built myself some alloy diff housings for my King Cab and the diff never slips again. But then I did start to destroy gears on gears...
The only cause of the problem is a slippery not present...


Max

[matisse]

Thanks guys!

thats a lot to think about, perhaps i'll try running it with out fisrt and take it form there.

matisse