Saving your Axles ! literally

[rustybeard]

If you drive your KB in loose impediments aka loose soil, loose sand (bad idea), loose gravel it is a good idea to remove the tunnel protecting your Main Drive shaft for a cleaning. Once clean re-assemble protection! I had the unfortunate experience of getting a smell pebble down there and every time throttle was given the shaft spun and either scraps, picks up or can even wedge its self so that damage is great. Removal is simple, WD-40 the shaft so that theres some slippery protection and you will be good to go hope this helps ppl.


IMo sand = sand paper to plastic parts !

[oreellyfool]

I def would agree with this. I have a small back yard track we use for our 1/18 scale stuff but some times jack up my KB and rally it. However it has very loose soil on it and have had small pebbles and sand stuck by my drive shaft and it starts grinding like crazy. Not a good situation.

[prototyp]

My Rally has literally ground to a halt each time it's been run in decomposed granite or soft dirt. I have no doubts about the power of the VXL motor as it's literally lathed sections out of the center drives, the result of little rocks and other pulverized stuff getting in through openings in the underbelly skid:






Secondary issue is dust and dirt working its way into the rear diff housing (this was only a couple offroad sessions after a full rebuild):



Solution: some self adhesive foam rubber weatherstripping to block off the openings; up front around the transmission output and aft near the rear diff input shaft.




Seems to be working...

[rustybeard]

very good idea, I so going out and doing this, loose impediments are killing me

[rustybeard]

anyone know a place to share images etc for here ? Got new Upgrades from www.Thetoyz.com hooked me up with a great prices on a heat sink and fan some aluminum tie rods fronts and rears, went with the green. Car is tight and the heat sink allowed me to use duel lipos on a parallel connector for like 35 mins before temps got up. FYI it was like 100* in Connecticut where i live today. It really works the fan sucks heat out from the motor has two large openings for air flow as well as having a shield for your esc side if you install it the right way

[QYKSLVR]

And there is why I dont run mine in dirt. lol

[prototyp]

Thought I'd share one more thing in the pursuit of saving center drives. QYK, you'd be happy to know the latest round of stones up in the center bay were collected on-road, so this could well happen to you.

The one last gaping point of access for rocks and things lurks under the motor. One would think there's little room here to do much, but turns out there's plenty of air:


Obviously my center drive has seen quite a bit of action (the black sticker around the motor is torn up on the underside as well):


Blanking panel prototypes:




And final version, cut from a thin flat part of a clear plastic container (strawberries or something), scored and shaped for a tight fit, and held down with double-side automotive trim tape. If you run a big spur gear, you'll probably need to be careful about thickness and shaping in that area:




Going to do some off-road running for the first time in a while tomorrow, will report back how all these mods are working.

[prototyp]

Ran the car hard Rallycross style and the under-motor shield worked great.





Still getting small abrasive bits in around the transmission output, so added a little more foam tape, should seal the center drive off almost completely now:

[prototyp]

Center drives and diff housings seem to happy and well-protected from the abuse, but I had to stop a bunch of times to pick stones out of the motor pinion and big spur gears (and sticks out of everywhere else).

I'm thinking one of those 'showercap' overguards is the only answer for really dirty driving.

[1979chevy.]

Man, you need a T-maxx for the way your beating that rally





God answers prayer,pray,believe,NEVER GIVE UP!!!

[prototyp]

Nah, gives it character. It'll be a Group B rally car when it grows up.

[Angrytetsuo]

I like the corrugated plastic pan you have in that second pic! Have you tried that with some speed runs? tell us more?!

[prototyp]

Yea, Stratocore splitter, belly, full rear diffuser. Works very well at speed.

I'm going to do a proper post about this setup soon... I had to buy the materials all in bulk. Just about done finalizing the design.

[Angrytetsuo]

Well it looks too cool!

[prototyp]

Since this thread sort of aggregates some of my off-roading cleverness, figured I'd add a couple more things to the list:

When running in decomposed granite, I noticed my steering block would get locked up:



This is likely due to the wheels throwing rocks directly at the steering works when they're steered. So, perhaps a shield of some kind will deflect some of the most direct shots.


Fabricated these from some flat plastic - think it was a tray from a fancy package of sliced cheese - and attached with some double-sided carpet tape:




Also, I had sticks and such get stuck in the spokes of the wheels, not to mention my outer wheel bearings getting all nasty with dirt, and soaked when running in the rain. Took some inspiration from the aerodynamic backing panels on F1 and prototype sports cars and made some hub-shields to snap onto RPM hubs. Also from nearly indestructible "cheese tray" plastic:



Rather difficult to make as they have to be cut very precisely. But the outer wheel bearings don't get wet (from splashing) even in the most aggro wet-road driving. They stay pretty clean in the dirt, and of course no sticks are jamming into the wheel spokes. Fwiw, also noticed these sharpened steering response with my aero rig installed, so they have an effect there as well.

[End0ver]

http://buy.traxxas.com/product_info....td44s29nnru407

Maybe this will help too

[dmata101]

Prototyp, what kind of off-road rims and tires are you using? They look pretty nice.

[prototyp]

Rims are HPI TE37; prolly too nice for off-roading but have some flex and have been super durable. Preferred off-roading tires are "Performance Touring" from R2 Hobbies. I was using worn HPI X Patterns for a while but something gnarlier works better... These R2's grip pretty well.

[FOXX]

Though it may seem counter productive, you might consider drilling relief holes in the under plate allowing debris to exit easier than it enters...

[scott_sms]

I just sealed mines.There was already a small stone inside the shaft, thankfully it doesnt need replaced yet. Good design by traxxas if they are trying to sell spare parts :L Thanks for the thread rusty

[reod12x2]

Rather difficult to make as they have to be cut very precisely. But the outer wheel bearings don't get wet (from splashing) even in the most aggro wet-road driving. They stay pretty clean in the dirt, and of course no sticks are jamming into the wheel spokes. Fwiw, also noticed these sharpened steering response with my aero rig installed, so they have an effect there as well.

actualy i found it quiet easy to make these although i cut them lop sided. other then that i have to try them next week or two

oh and the dirt deflection does it cut down on how much grim the larger bearing gets in the axel carrier?

[prototyp]

Good, good. I challenged a few #11 blades cutting mine. The slippy plastic and intricate cuts had me a little worried about my fingertips, too.

The big inboard bearings still get grimey, unfortunately. Maybe a bit less-so since dirt isn't being pulled under the car from outside the wheels. Still need to think through some screen or filter (that foam weather-stripping?) to keep dirt out.