The 2mm screw is what most TC cars use and they don't have any more trouble with that than with anything else. If a mod TC car can use that screw, I don't expect you would have any more trouble given you have much less power. Try it and see how you go.

I have to mention here, quite a few people at our track broke that screw in TRF cars and my impression grew that it was something to do with Tamiya and their screw/diff. They then changed it to a "normal" 2mm capscrew you can get at most screw places and problems went away. No reason to buy the Tamiya screw if you don't really like it, and I agree it's expensive for no good reason. But then again such is everything with Tamiya.

The only change is that you may have to use a hex driver to adjust the diff if you don't cut a slot in the screw head.

Not sure I follow the cutting a slot bit.
The M-05 ball diff needs a hex driver for tension. What do you gain by slotting the head for a screwdriver ?

True, I keep forgetting that. In a TC car, the screw comes with a big slot which allows a long thin rod to be inserted through to lock the screw when tightening up the diff. I keep forgetting the M05 balldiff comes with a cap screw and this doesn't exactly line up with the outdrive slot so this may not work on minis.

The reason the screw works on a TC and fails on a Mini has nothing to do with the power the motor is making. In the Mini, the idea is to tighten the diff way tighter than you would in a TC to get it to act more like a limited slip diff. People also use AW grease in the diff to get the same effect. In a TC, you want the diff to be just tight enough that it doesn't slip so you tighten it till it's snug then back it off till you have the right tension on the spring.

I see no reason to cut a slot in the screw. Every one I have seen is tightened with a hex driver.

Andy

The right tension on the spring depends on motor power and grip available at the wheels. The more power and more grip, the more likely the diff will slip unless is tight.

If the screw head doesn't line up with an easily accesible opening there is little reason to slot it (you could space it out if it was long enough). In a TC you actually have an access hole in some cars (Xray, latest tamiya, etc) whereas others are built such that the screw head is accesible through the outdrive slot.

Tim please check your PM thanks

Tiko

I heard that there is an Suzuki swift body of an other brand then Tamiya wich fits on the M03S chassis. (rover mini cooper version short wheelbase).

Does someone know where to get it and of what brand it is?

Power and grip have nothing to do with overly tightening the M05 diff screw. As Woody said, its about making the diff action more like a spool, so you get better drive out of the corners.

I found a good replacement screw. Its made by Losi for their 1/18th MT. Can't remember the part #, but it is gold color(titanium coated), has a slotted head & the shank isn't threaded all the way + it comes with a heavy duty nut. Haven't been able to break that one & my diff is really tight; to the point that the thrust bearing has become. the next weakest link; broke 2 so far & looking for a better replacement

Colt makes a mini Swift in the short wheelbase

And I belive RC-Mart(Dinball on ebay) has these for sale.

Mario / Woodys, I agree totally with your theories. I was trying to not flame Niznai , for once again handing out very questionable (IMO) information.

Basically you need it as tight as possible. As your torque is transmitted through only two tyres, it is critical to limit slippage.
On high grip surfaces , a dedicated spool makes my car wander too much at speed,though exit drive is awesome.

So I'm after a super tight ball diff, for max drive. I now have a Venom ball diff, which i'll look at modifying for durability and uprated clamp load.
Will post results...

Okay--- I'm trying to find Long wheelbase bodies for my new MO 5's--where is the best place to find these? Looking at Ebay---there's a lot of them out there--but shipping from overseas is expensive. Is there anyone here in the states stocking these guys?? I picked up a new MO 5 kit---but the body in it is for a short wheelbase--and I would think--longer is better if these things are a little twitchy!!
So HELP!!!! What's the best answer???
Tim

Just pick up a 06 Mini Cooper from Tamiya....thats a LWB and handles awesome!

And how exactly, may I ask, is what I said above different to what you said?

I am aware of what you're trying to achieve.

Regardless of what your reason is to tighten the diff the same laws apply and the key limiting factor to all of this is friction, be it between wheels and road or balls and ballrace. What you're trying to do is balance the grip available at the wheels against the friction generated by the tension on the spring. You can indeed tighten the screw until your diff is well and truly locked, if there is no grip at the wheels they'll just spin. If there is enough, then come first corner your wheels will fight one another and something has to give. If the diff doesn't slip, then one of the wheels will. Past that point there is nothing to achieve no matter how much you tighten the screw. And I don't think at that point you would have tightened the diff screw more than in a TC car with some real power.

But that's beside the point anyway. The idea is you can get a grade 12 M2 screw at a good nut and bolt place.

:lol: Don't get your knickers in a twist. Other people are entitled to their opinions. Some of the info you post is misleading & we don't want any noobs to Mini to go down the wrong road.