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How hard can it be?

I see an unused, new SC10 transmission complete with engine guard and bumper stays going cheap on eBay and after a bit of comparing decide it might worth trying a swap to protect the vintage 6-gear transmissions I'm using with the brushless/lipo power options I'm playing with at the moment. The width of the output shafts is the same as the 6-gear, but they sit a little higher.

I use my beat-up, heavily drilled SWB gold-pan as a test bed for the first try as a few more cuts and holes won't matter.
As the SC10 tranny does not fix directly to the chassis I got hold of the SC10 engine plate and cut a few corners off it to get the transmission to align with the stock RC10 rear arms and hubs. After drilling six extra holes and digging into the parts bin for suitable nuts and screws, the bottom fixings were done.
I then decided to buy the SC10 shock tower and fixing bracket to provide the suspension mounting and turnbuckle points as the stock RC10 bulkhead was not looking usable due to conflict with the rear of the SC10 tranmission..... However, to get this to fit there was a bit of relieving to be done to the fixing bracket and the removal of the two side tangs of the pan which normally tie into the RC10 bulkhead.

So first try got it to fit reasonably well with stock rear arms, mounts, hub, turnbuckles and dog-bones. (I used RPM arms and B4 shocks, but stock should work). My unresolved problem at the moment is that there is nothing to stop the flex of the whole of the rear section and I need to somehow add a brace between the shock tower and the rest of the pan. I may go back to looking at modifying the stock bulkhead/rear tower as this would fix the problem to an extent.

That will be try 2.

Is it stiff enough, or do you need some sort of upper brace between the tranny/tower and the chassis? Also, if it was me, I'd hack off the rear body supports, since putting a wing that far back would only exaggerate the cars rear weight issues.

yellowdatsun wrote:Is it stiff enough, or do you need some sort of upper brace between the tranny/tower and the chassis? Also, if it was me, I'd hack off the rear body supports, since putting a wing that far back would only exaggerate the cars rear weight issues.

Very flexy at the moment, especially as the 'lightened' chassis has holes in just the wrong place. I will eventually apply the end result to a whole, good pan.
Those arms at the back are for the SC10 bumper system. No use in this configuration, but may need to find some suitable wing mounts.

you need an A&L chassis brace. o wait lol never mind just noticed u cut those rear screw mounts where the rear bulkhead was

I really dig that. I put one of those in my T4 as well. The diff is impressive.

Try 2.
Decided I was over-thinking it and went back to sizing up the original RC10 bulkhead. it just about fitted after cutting down the SC10 transmission base plate some more to sit against the bulkhead. The plate only really has value as a location device for the square base of the SC10 transmission and location points for the SC10 engine guard to the rear.
I found that if I fixed through the engine guard/base-plate into the existing transmission mounts via two new holes in the pan the whole thing was a good snug fit. Adding a couple more screws through the existing forward stealth transmission holes into new holes in the SC10 base plate tightened the whole thing up more.
The front of the transmission is bang against the bulkhead so it was just a question of tying it in using a standard servo mount block drilled to take an extra screw to fix horizontally through the battery box.
With the rear arm mounts in their rearward position the dog-bones are angled forward slightly, but no more than they are angled slightly back in the stock configuration.
The whole rear end is very stiff now and I'm happy with the result as it is much simpler and uses more of the stock components including the shock tower. The ride height is just about right even though the outputs are a little higher than stock.
More later when it is up and rolling.

I love how adaptable all these parts are.

Did I see that correctly, that you only needed 2 extra holes to mount this transmission?

I guess the SC tranny is like most other modern ones that you need a square or rectangle hole / recess for the whole unit to sit lower, right?

Chewbacca wrote:Did I see that correctly, that you only needed 2 extra holes to mount this transmission?

I guess the SC tranny is like most other modern ones that you need a square or rectangle hole / recess for the whole usnit to sit lower, right?

Yes. Two new holes in the pan and one in the bulkhead. And yes, to get it to sit lower you would have to cut a square hole in the pan. (Seems OK though sitting a little higher than stock)

Pretty awesome!

did you ever run her yet?

No. Got her all ready to go then had an ESC problem. That plus the holiday season means the bench has seen little activity of late, but hope to give her a good shakedown soon.
I'll report back!

Well, got it all together with a new Turnigy 9.5T brushless sensored motor, a SkyRC Toro TS50 ESC, Absimma radio gear and a 2s 5200mAh lipo.

It went as good as it should with the stock SC10 spur and a 20t pinion. Very fast off the line with care needed not to loop it, and no obvious issues emerging.
The tranny is just great with the only problem being an occasional popped dog-bone when the rear shocks are tested to their full extension over the really rough stuff. This is because I think the raised level of the outputs within the stock suspension geometry is just asking a little too much. I'm guessing some extension limiter in the shocks or a higher top mounting will sort this. Otherwise, success!

Just looking back at this I'm pleased that the end result is a competent and well-running buggy made up of a parts-bin mix of components spanning at least 30 years. Astonishing that the RC10 can still give you this in these days of ever-changing technologies and throwaway consumerism. Excellent fun.

Finaly added a Mirage body and vintage wing. (A non-Associated black wing is on the way, just put the vintage one on for snaps)

Final tweaks: New wing, carbon shock tower and Team Car shocks. Black wheels and tyres from the 'The Box'.
Happy.