4wd Corr/Pro-4 Truck REDESIGN POSTED 12/23/09
 

Just this past weekend I acquired a Stampede rolling chassis, but knew the 'Pede isn't for me, especially since the new rage is the Slash. I tend to not like conventional/stock things, though. Right away the thought of a 4wd Slash (non-Slayer) was running through my mind, since I have a Rustler I can steal stuff from. But even a simple 4wd Slash would be too easy considering I made a 4wd Stampede ("4x4 'Pede") several years ago.

Then I read about a member's dislike for the Slash's lack of solid-axle rear suspension. This led me to the ultimate RC Corr truck - a 4wd independent front and solid axle 4-link rear suspension truck. I've been working with solid axle/4-link suspension on crawlers for well over a year now so I have plenty of parts to work with and a pretty good understanding to go off of.

Right now I am stuck on what exactly to do with the rear - use a Wheely King or AX10 axle like you would normally see, or go with a Slash rear end, modified to have locked suspension arms and with an added 4-link? The former option would more than likely require a chassis-mounted motor/gearbox along with a motor in the front transmission. The latter option would decrease ground clearance and would probably increase complexity (because the Stampede/Rustler/Bandit/Slash tranny is not at all designed with 4-link suspension in mind).

What do you guys think?

Sounds very interesting. I've loved solid axle since my TXT1 but parts were too expensive back then . Though the motor/transmission would be a bit of an obstacle IMO. But hey we all know you always find a way to fit things no matter how hard it is :lol:

Hope to see more into this project :yes:

Something like a tamiya pajero/wrangler? Can't remember the chassis number, but it has independent front suspension, with a live axle rear and awd. Hopefully you can make it a bit simpler than that chassis...

How about a flat chassis with the rustler tranny in the center, with one output going to a real live axle, and the other output going to a front diff, like a crt.5, or touring car diff. Finding the correct diff to match the rear gearing may be fun...

Use rpm rustler rear arms and traxxas rustler sliders all around, with the rpm bearing carries and hubs. That way you can run 12mm hexes and 2.2 wheels/tires.

You could raise the center tranny up for more clearance if you like. Not sure what to use for center drives...

A buggy front end, centre diff and motor mount and a solid rear axle would be sweet. I would use the strongest axle you can find that is closes to the width of the buggy front end. I'm not much of a fan of dual motor set ups. Dual motors could give some interesting power delivery though.

Different diff ratios front and rear would make for some interesting torque split options front to rear. It would make the centre diff work hard but it would be interesting especially if you could change the ratios easily.

A std buggy front end and a narrowed xtm x-factor rear axle would be the ticket. Both use 13/43 gear sets, and plenty of people have narrowed the xtm axle.

Unfortunately the X-Factor parts are discontinued and difficult to obtain even for a guy like me who works at Hobby People... Not to mention I've heard of differential problems with the stock nitro motor.

But even then the X-Factor axle would be difficult to narrow without sacrificing a lot of strength, and with the use of a 1/8 buggy front end the whole truck would be quite a bit heavier than what I'm shooting for.

You guys are providing great ideas, and have made me think more about this. Previously I had not considered the front/rear differential ratio issue. Here's another idea - Wheely King or Axial rear axle, and MT2 front end. This setup can be made to take a lot of abuse, is much closer to the weight I am shooting for, and the front/rear end would have the same differential ratio.

Thoughts?

Sounds good, both have the same diff ratio? Whatcha think about my pede tranny in the center idea?

I have built a few crawlers that use the pede tranny for the center trans. Question is, do you know where to scare up a locker for the pede diff? I once saw one on ebay that had a solid center shaft that connected to a piece of al that replace the cover of the diff. It eliminated the spider gears and outputs. Wish I could find that item agin, my slash has terrible diffing out problems.

I like the idea of the stampede tranny, How about a goliath axle case? you should be able to use TC3 diffs and use a TC3 front case

Buggy front end , Axial rear with 4 link and SS or any aftermarket lockers , straight axle conversion and go with a Ae stealth tranny .

The Wheely King and AX10 use the same differential gear ratio as the MT2, 38/13. And now that I think about it, I could unbuild my not-quite-so-successful "direct-drive to diff" MT2 18SS for its front end and hardened differential gears.

As for the Stampede tranny idea, it'd work if I were planning something more conventional... Which just isn't me. When I can help it I don't use transmissions for 4wd (of all my 4wd vehicles my Dark Impact has the closest thing resembling a transmission).
But if I were to use one and lock the diff, I'd go straight for JB Weld. One time I locked a 'Pede diff using JB Weld and left a little grease in there. When I went to remove the JB Weld "locker" it pulled right out, thanks to the grease.

On the topic of what will go on the center, what are your guys' thoughts on direct-drive to diff? I ran the numbers and it looks like a 2826/05 (900 kv) would work almost perfectly with 4s2p A123, giving a top speed of 40-45mph. This would be super lightweight, with great overall efficiency (which as we all know means longer runtimes).

I haven't looked into the Goliath axle, do you have any specs on it? But to me it seems like plastic TC3 diff gears might not hold up to the abuse of almost 4.5" tall tires.

Buggy front end, as in 1/8 buggy? If I went that route the front end would be under-driven which wouldn't be easy on the front or rear end (3.31:1 vs. 3.92:1). The AX10 axle in the rear is currently a possibility, depending on its track width, since I want to match the Slash's track width to fit the Slash body (actually the Proline Hardcorr). I commented on the center tranny idea above.

The MT2 front end option is becoming more viable... Turns out the track width of the MT2 front end is almost EXACTLY the same as that of the Slash's. If anything it's no more than about 1/8" narrower than the Slash. PERFECT.

Onto the rear solid axle: The AX10 axle is WAY to narrow, it needs to be about 2 1/4" wider. I'm gonna find out the comparable width of the Wheely King axle soon.

I really like this idea. I have a fondness for scale type builds. Have you ever poked around on scale4x4rc? There are lots of good builds there on prerunner type trucks, with live rear on 4 links, and IFS.

I have this tamiya cc-01 touareg that I have modded pretty heavily. I've had thoughts of building a 4wd corr truck using that and 1/8 buggy front end. Again, the diff ratio's are what always held me off....

Sounds awesome :). I'll keep an eye on this one...

Actually I have never been on Scale4x4RC. When I get some more time I'll see what the members there have done.

The Wheely King axle is about 3in. narrower than the Slash rear end. There are some axle widener things for the WK that I will check out when I go into work tomorrow.

Since you're solid in the rear, and IFS up front, you could also probably use 1/2" offset rims in the back, and no offset up front. That'll get you an inch closer....