Thanks guys, I picked up the original, vintage TTC in a rather expensive purchase of a Madcap it was fitted to. I have now disassembled that car, started to use the TTC on this car and the chassis is destined for my future build of a mint shelfer Madcap, as its the cleanest chassis I've been able to acquire to date.
Since considering the option of fitting a 2018 Super Astute TTC and then looking at acquiring the parts to build one, it is apparent that it is now near on impossible due to the discontinued parts by Tamiya and the rarity of what's out there now globally amongst both shops and private sellers. So it happened that a nearly complete, unused one popped up on eBay this week (anyone on this forum perhaps?), I struck a deal for it and some other rare Astute parts and now am fitting that to the car instead.
The modern slipper clutch on the TTC is much better in my opinion, sure it doesn't have the nostalgia, but I have that in the original TTC that will now probably go in a shelfer or become a stand-alone piece on the shelf. What it does have is a better design and construction, with much more adjustability.
Fitted the aluminium gear support brace that came with the vintage TTC (these are about £40 delivered to the UK from the US if purchased separately) and this should ensure even more reliable running.
The 2018 TTC purchase didn't come with a polycarbonate gearbox cover, so I picked on up from Revive RC. Very good quality, not quite as detailed as the original vintage cover, but very good and very tough as well.
I pushed the gearbox plate into the cover...
...and cut it out with a sharp blade...
Using the vintage cover as a guide I then marked and cut out the hole for the slipper clutch adjustment nut with a scalpel. I considered drilling this, but it proved a little tricky to find the dead centre of the circular top section where the hole sits. Cutting it out was a bit of a ball ache as the polycarbonate is really quite thick on this repro piece - I consider that a good thing though of course as it should prove very durable I hope.
Beyond the photo above (which shows the rough cut done with the blade) I sanded the hole to shape, periodically testing the fit of the little plastic dust cap that fits in there for running. I was able to shape and centre the hole in the case and then ended up running a 10mm drill through it. Result was a nice snug fit, but it took a bit of time and careful consideration.
Existing Madcap/Astute ball diff gearbox with standard 70T spur before removal. Note the carbon gearbox plate, which is a nice touch on this one.
Cocked up on the pinion for the 2018 TTC though! The vintage TTC is able to take between an 18T- 23T pinion.
As I was originally planning to fit the vintage TTC until I found its shortcomings, I had bought a 19T pinion for the gearbox switch. It wasn't until I fitted the 2018 TTC and offered up with motor and 19T pinion that I realised it wasn't going to work with the 2018 standard 82T spur gear. The 2018 manual states it will take a between a 23T-27T pinion gear, so 19T is well beyond that spectrum.
With the motor rotated right forward it hits the casing...
...and the 19T pinion can't mesh with the spur gear...
Paying a but closer attention or doing a little more research on my part could have flagged this up sooner, but hey ho. There is a lack of steel 0.5 module pinions out there. Although below the 23T limit stated in the manual, I have managed to pick up a 22T one and considering the 19T is almost able meet with the spur gear, going up 3 teeth I hope will enlarge the diameter of the pinion enough to mesh well with the standard spur gear.
@Fruitfly01, do you know where I can source other 3 spur gears for the 2018 TTC that you mentioned in a previous post buddy?
So for now, here she is fitted, with no pinion for the moment of course...
Beyond the pinion hold up, some other minor issues:
*The adjuster lock nut fitted to the end of the slipper clutch shaft was incorrect and when set up at the standard setting (tighten fully and wind back 2 and 3/4 turns) the nyloc part of the nut was pretty much all off the shaft, which would be no good for running. Luckily I had some of the correct nuts, so fitted with no bother.
*As my 2018 TTC purchase didn't come with the polycarbonate cover, it also didn't come with the dust cap for the slipper adjustment hole (part A5). So I have currently fitted the vintage cap. Not ideal as it leaves me without one for the vintage one of course. The part is from the Super Astute A parts tree, which in the past few months seems to have become uber rare (along with most other Super Astute parts), so it's unlikely I'll be able to pick one up. As I know the hole is 10mm, I think I'll look for a 10mm rubber bung for this runner.
*The seal around the clear gearbox casing is pretty poor and I can see dust and dirt will easily get in. I don't think that is an issue with the aftermarket cover, as I've read before that this can be a shortfall with the TTC gearbox. So I am looking at some 0.5mm or maybe 1mm very thin gasket material that I could cut to shape and fit around the edge of the gearbox plate to gain a better deal from the elements. Not sure if that will works, but it's worth a shot I reckon.
Anyway, so currently I await the arrival of what I hope is a suitable pinion to be able to progress to running the buggy again...