Does the volcano stx have positraction? Just wondering, because if it does, somethings wrong with my rear differential

I dont think so. Just straight up 4wheel drive. My fornt diff. is broke on my volcano sv.

posi traction is not offered at all in any car truck or buggy that i know of.
i once looked into this and found that it is possable but not good.
so there must be somthing else wrong with yours
what seems to be the prob. add a little detail.

well, because they dont have it, then my rc is just fine. What happened was i saw that only one back wheel was spinning when i held it and gave it throttle, and i was worried. but since it doesnt have positrac., then its just the differential doing what its supposed to do. Thanks for your input!

FYI. I've read in other forums of people making the rear diff posi with acceptable results. I haven't tried it yet but the best one I read was to fill the rear diff with Silly Putty. It's completely reversable if you don't like it and I don't see how it could cause any damge. Turning may be harder on hard or high traction surfaces but in loose dirt and sand it may be cool. Just fill up this part with putty and pack it around the gears.

Oh BTW I got some of my parts and rebuilt the rear diff. This pic is of the inside of the beat rear. You can see the teeth on the big gear are chewed up. The pinion was worn out bad too. I'll try to post a picture breakdown in the FAQ on how to rebuild it in the next couple of days.

Hey thanks Chubbysuncle for doing that! It really helps us new guys figure out whats wrong and how to fix it. hope your rebuild goes alright. Thanks again!
-Brian

what about using a really thick grease in the diff?? wouldent that stiffen it up a bit but still let it turn ok?? im thinking like 50wt gear lube or a little lucas oil stabalizer. its really thik n sticky

...and wouldent silly putty wear out the gears in the event they did turn?? i never thought of putty as a lubricant

it wouldnt be a lube. it will do the same thing if you put never drying clay in it. what posi traction?

It's when both wheels spin the same direction at the same time. It's short for POSITIVE TRACTION.
You will often see muscle cars spinning both rear wheels leaving 2 strips. That's posi. If you see 1 strip, it's not. They call that a one-legger... Posi offers maximum traction when both tires hook up at once.

Nice description Abjones

put a super thick diff fluid if ur diffs can take it. OR, just use JB weld and lock up your diff.

JB Weld would be PERMINANT!!! I like the silly putty idea or thik diff fluid, you can alway switch it back

BTW what kind of lube are you SUPPOSED to use in the diffs??

... diff lube[sm=spinnyeyes.gif]

duhhh what weight diff lube? does it matter? wouldent pretty much any oil/grease work?

i would put 3-in-one oil in there personaly if i had to put anything in it at all.

That wouldn't work too well. It would break down too quickly and that's totally not what it's designed for, not to mention it's really thin. Automobile differentials require a MUCH thicker oil than standard motor oil. Even the thickest motor oil, 20W-50, is thinner than diff fluid. An average diff fluid is 75W-90 - MUCH THICKER! I believe you could go with a hi-temp grease in an R/C.

Open yours up and see what's in there...

yea i know.i think that my dad have some grease/gel i could use... even though i dont need it.

quote]ORIGINAL: mozzzy_2000

in regards to diff oil, its usually a personal preference & the surface you most likey run the car on. I would certianly use high quality silicone oil. The theory being that the thicker or the heavier the diff oil, the harder it is for the engine to drive the wheels. So in other words, if you are running on a loose surface you would not want you front diff you spin widly out of control. You would use a stiff oil to reduce wheel spin. Conversely on a high traction track, you would probably use a thinner oil.

The weight of oil will also affect whether you get under steer or over steer. This is so for front & rear wheels and will affect the way you come into & exit corners. The front & cente diffs seem to be the ones that are most sensitive to oil weight & seem to determine the overall performance & handling. The rear wheel obviously don;t lift off like the front does so, you want a thinner oil in the rear so that you maximise drive.

With that in mind there are general weights or diff oil to use in most conditions. If you have the time to tear down your diff & change the oil, you can experiment depending on how you like the car to handle. The stock Redcat/Himoto & Bazook have grease in their diffs. While there is theorectically nothing wrong with diff grease, it is not ideal & you wont be able to change the handling characteristics.

So generally it goes like this.

Front: 3000Wt - 5000Wt

Centre: 7000wt-10000wt

Rear:1000Wt-3000Wt.

In mine at the moment I have 5000/7000/3000 in my himoto and on grass it is awesome to handle. Off-road on loose surfaces though its a challenge & I have yet to experment with the diffs on those surfaces.

The only thing thats a pain in all of this is that you need to take apart the diffs, clean out every trace of grease & then fill it up with the silicone. Its not a bad way to spend the afternoon if you haven;t anything else to do and you'll instantly feel the immedate effects on the handling of the car.

I don;t think my diffs had o-rings either so they can be added for better performance. I have also found that the diffs from the Ofna Hyper 7 & 8 and both the kyosho inferno MP7.5 & MP777, are all the same size & all fit the redcat/himoto/bazooka. I will say though that some diffs have aluminium spur gears & you want avoid those. The stock redcat & Himoto diffs are infact good quality steet gears & so far mine have taken a hammering!

Hope this helps!
Matt
ps. watch that silicone oil! whatever you do, don;t get it on the foor!!! haha
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