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What do you do when you have 89.7% of a complete truck?

You build another one..... a runner !


After all was said and done it turned out I had a bunch of leftover parts including some pretty fancy ones at that. All I had to do was order another Factory Works conversion and a pair of slash rear arms.

Since this will a runner I swapped out the worst chassis of the bunch. This is what I started with.




I was never going to use these blue bits but why not do a Pro TRX-ish build, and I must say so far it's turning out much better than I thought it would

RC10th wrote: ↑Wed Dec 11, 2024 8:57 am After all was said and done it turned out I had a bunch of leftover parts including some pretty fancy ones at that.

Uh oh.... 'pretty fancy' parts doesn't sound like making a runner. I think these leftover parts have some rabbit DNA in them. They know how to multiply their numbers.

Looks like a nice start! Maybe too nice for a runner.

Frankentruck wrote: ↑Wed Dec 11, 2024 9:07 am Looks like a nice start! Maybe too nice for a runner.

The RJ Curse strikes again, hey @RC10th

These SRT’s are pretty cool, and this one is looking very nice so far. So is this number 3?

RC10th wrote: ↑Wed Dec 11, 2024 8:57 am What do you do when you have 89.7% of a complete truck?

You build another one..... a runner !

Vintage RC mania knows no bounds!

Incredible_Serious wrote: ↑Wed Dec 11, 2024 2:54 pm

Frankentruck wrote: ↑Wed Dec 11, 2024 9:07 am Looks like a nice start! Maybe too nice for a runner.

The RJ Curse strikes again, hey @RC10th

I have many curses

mtbkym01 wrote: ↑Wed Dec 11, 2024 3:24 pm These SRT’s are pretty cool, and this one is looking very nice so far. So is this number 3?

Thanks, this one makes #4. I didn't plan on it, it just kinda happened

Frankentruck wrote: ↑Wed Dec 11, 2024 9:07 am

RC10th wrote: ↑Wed Dec 11, 2024 8:57 am After all was said and done it turned out I had a bunch of leftover parts including some pretty fancy ones at that.

Uh oh.... 'pretty fancy' parts doesn't sound like making a runner. I think these leftover parts have some rabbit DNA in them. They know how to multiply their numbers.


Looks like a nice start! Maybe too nice for a runner.

They do seem to be like rabbits, I wasn't going to use the blue parts anyways so I guess it doesn't matter, but if it turns out great it will be all that much harder to get dirty and scratched.

TRX-1-3 wrote: ↑Wed Dec 11, 2024 4:39 pm

RC10th wrote: ↑Wed Dec 11, 2024 8:57 am What do you do when you have 89.7% of a complete truck?

You build another one..... a runner !

Vintage RC mania knows no bounds!

Absolutely !!

RC10th wrote: ↑Wed Dec 11, 2024 7:20 pm

Incredible_Serious wrote: ↑Wed Dec 11, 2024 2:54 pm The RJ Curse strikes again, hey @RC10th

I say so many curses

Fixed it for you, mate....

Shock towers, rear bulkhead, turnbuckles and the likes....

No fancy titanium turnbuckles but the Traxxas ones look pretty good on there and suit the build.

This is where the build starts to stray a bit from my other ones..... The gearbox....


Since I went big when I planned to race these things I bought three sealed gear diffs so I could have different oils in them ready to swap out at the track..... until I found out they were over twice the weight of a ball diff. I would still rather a ball diff as I'm not a fan of gear diffs, and since this is made of parts I'd never use otherwise it makes sense to use it now. I do have a third planetary gear set somewhere, I couldn't find it for the photo.




After reading just about every post I could find on sealed gear diffs for Traxxas and discarding 98% of them from the rubbish posted by bashers and know it all's I thought I'd give 20,000wt a try from info by the other 2%. The diffs are planetary which require a much thicker oil than bevel gear diffs. The diff feels pretty good, I used green slime and didn’t overfill it, which I think is the problem most people have. It's surprisingly smooth ! Anything is better than the stock unsealed gear diff.

I had a complete RPM gearbox so I cut the ears off just like I do for the Hot Racing cases.


The RPM case is said to eat idler gears but when I tried to research it further I'm not so sure it's as big of a deal as claimed. I'll give it a try and make my own opinion. I went with the stock internals.


I chose the original slipper design to keep it somewhat old school. I'll have to fill the spare slipper peg holes with more pegs..... The pegs weren't fantastic then and I'm sure they aren't fantastic now


I cut the case to make it look less Traxxas-ish. I would have liked to cut it back a fair bit further but due to RPM's strange gear cover bracket a new design bracket would have to be made and I didn't want to ruin this case just yet.

Looking good so far,

Now I do have some suggestions if you don’t mind, especially for a runner, if this build doesn’t become too nice for that.

First of all, why’d you cut off the ears on the tranny case? I am sure you are aware yourself, those use a longer screw from the arm mounts to attach to. It should work with either the RPM mount or the Traxxas Nitro rustler mounts. Perhaps some shaving or shimming required.

Secondly, if you use a Kimborough spur gear for a Rustler I believe there are 2 concentric rings of holes that just barely fit under the original slipper plates, if you fill all of these holes with the pegs, you more than double the friction surface and might actually get a half way decent slipper out of it. I am going to try that on one of my radiators hopefully soon.

Now, make the suspension symmetrical you should use the RPM mounts in the rear and the wider RPM front arms.

Throw on some modern offset wheels, and you have a WOIN-ish Quadra Symmetric SRT.

I have something along those lines in the pipeline, should I ever get around to it.

Chewbacca wrote: ↑Thu Dec 12, 2024 11:59 am Now, make the suspension symmetrical you should use the RPM mounts in the rear and the wider RPM front arms.

Throw on some modern offset wheels, and you have a WOIN-ish Quadra Symmetric SRT.

He used Slash rear arms, which should make the width nearly even.

When using the wide offset Traxxas wheels all around, the width should be correct.

With the wide front arms and Rustler rears, you need narrow offset (electric rear) for the correct width ( it'd be tight around the steering blocks). Unless, you are intentionally building a wide track vehicle (I have two, using the Pro-line wide arms).

I believe that modern wheels fall into somewhere in the middle, which may still be acceptable. Or maybe too wide.

juicedcoupe wrote: ↑Thu Dec 12, 2024 1:07 pm
He used Slash rear arms, which should make the width nearly even.

Sorry to side track this topic a bit, but since you mentioned it, where do the slash arms fall in width wise? I have Rustler rears and Nitro Rustler rears. Are the Slash like the Nitro Rustlers or somewhere in between?

Thanks, Tony

Chewbacca wrote: ↑Thu Dec 12, 2024 1:19 pm

juicedcoupe wrote: ↑Thu Dec 12, 2024 1:07 pm
He used Slash rear arms, which should make the width nearly even.

Sorry to side track this topic a bit, but since you mentioned it, where do the slash arms fall in width wise? I have Rustler rears and Nitro Rustler rears. Are the Slash like the Nitro Rustlers or somewhere in between?

Thanks, Tony

Just measured:

RPM Slash rears: 82mm, pin to pin.

RPM/Factory Rustler rears: 92mm pin to pin.

I believe that Slash arms have some toe-in made into them, while the Rustler arms don't.

The RPM wide front arms copy the length of the (discontinued) Pro-Line ProTrac arms, which are 10mm longer than factory.

The Pro-line ProTrac arms were originally used on their Pro-2 truck and buggy, as well as a long arm conversion for the Slash. It had SC wheels with 10mm more offset than standard.