'shot series drive cup wear.

[Wandy]

Ok, I now have my hotshot runner kitted out with shiny new transmission parts....gears, bearings, axles, dogbones, drivecups etc. I've been browsing the site and have read various comments on how the dogbones eat the drivecups & axles for breakfast and there are various ways to slow the wearing process down. I've read all sorts of comments from inserting rubber rings inside the drivecup/axle to not putting any grease at all around the drivecup.

Can someone explain the logic of these and other theories? How do I keep this transmission in the best possible order?

No comments saying "dont run it" please! []

[ukzz4iroc]

Back in the day I used to cut of a 2mm section of nitro fuel pipe. Then I would put that 'o' ring inside the cup or cups if preffered. This then ensures there is minimal longitudal movement and minimises wear. Also don't overdo the grease as the areas are quite exposed to dirt etc and this means the grease traps the dirt and can really abrase it.

Hope this helps?

Felix

[Wandy]

But by minimizing the longitudinal travel isn't that simply going to result in one smaller area of the drive cup slot getting all of the wear rather than spreading it across the whole slot and increasing the life of the part?

[UltegraSTI]

same methods apply today with 1/8 scale buggies and truggys. i still plop a splice of fuel tubing or old shock orings in teh cup to keep the shafts from binding or floating too much.

cut your lengths down to what feels right. not too tight or loose.

good luck

-R

[DJTheo]

Better also not to grease them at all or use few of the newer anti-wear grease from Tamiya.

Cheers

[mud4fun]

I don't bother greasing my drive cups/dogbones any more as it just atracts dirt and acts like grinding paste.

The drive cups/axles on my thundershots are actually the same as the TL01 so I just buy lots of them from my LHS as they are really cheap. I think the hotshot used that same style drive axles too in which case you could use the TL01 drive cups as well.

I'd recommend fitting uJ driveshafts to the front because under hard cornering on maximum lock the suspension can droop so far on one side that the dogbone slides completely out of the drive cup and binds with the steering upright - this leads to bent dogbones and broken uprights.

The little 'O' rings inside the drive cups are to stop the dogbones from moving too far from side to side within the drive cups causing disengagment as above. I found this out recently on my crawler which uses dogbones and cups. If found I need an O ring in each drive cup although Tamiya only reckons they are needed on the inboard cups.

I haven't personally suffered excessive wear on the dogbones or drive cups, at the end of the day they'll wear out eventually like all moving parts but the system is far superior to earlier uJ designs - as proven by the fact that Tamiya still use this system on just about every vehicle they make.

[ideal2k]

Don't put grease in the cups - that attracts dirt and grinds like sandpaper! I can confirm mud4fun on this.

[terry.sc]

On the Hotshot the reason for the o rings in the gearbox joint was purely to stop the driveshaft falling out at full lock, rather than anything to do with wear. Never grease drive cups, it just attracts dirt. Either leave them dry or use a teflon dry lube.

[Wandy]

Staying on Hotshot topic, I recently bought a Hotshot II runner, mainly to strip down and use as spares for my Hotshot runner but also so that I could fit the rear shock absorber set up to replace the mono-shock.

When dismantling the rear wheel bearing carriers from the wishbones I noticed that the screw-pins were very tight and that the thread was stripped on some of the wishbones so that the pins could not be tightened, but put this doen to age and hard use.

Anyway, when refitting everything back together I was suddenly baffled to realise that the wishbones would not line up with the bearing carrier, infact they were miles off and even when trying to force them inline I couldn't do it.

You know what's coming here dontcha? The previous owner had fitted Hotshot wheel bearing carriers to the Hotshot II wishbones!!!!!!! God knows how he did it and even more amazingly how they had managed to stay unbroken on the car. I would loved to have seen how the rear suspension had worked when he had the car running!

[spannerboy]

in the associated rc10b3 the manual says put small springs in the drive cups. this would be a good idea as the springs would keep the dogbone perfectly aligned at all angles