Unloading of diffs...can someone explain
 

Some people talk about their diffs unloading..what exactly is that and what should I look for...and to correct the prob, just change diff fluid?

Simplest way to explain is a demonstration- grab a wheel, then hit the throttle; the opposite wheel will spin twice as fast as it 'unloads' (same theory with a center diff). Its all to do with the internal gearing of a diff and its design to split power/ allow one wheel to turn faster or slower when turning a corner. Thicker diff fluid will tame then effect, which can help or hinder steering performance depending on the track etc.

I thought that is was something like that...thanks for the info!

So the center diff fluid would be the one to change, correct.

Us thicker center diff fluid if you notice the front tires spinning faster, and growing very big on hard acceleration. If you go too thick You may notice that the truck does not turn as tight as before. The thicker fluid helps the diff put the power to the rear wheels, but will also limit the difference in speed between the front and rear diff when turning.

Magman, sorry to ask this question on your thread. linc, u seems to know alot about diff fluid, so I hope that you can give me some advice. I have a heavy BL truck, about 13lb with UE 8 spider diffs, what diff fuild should I use..?

I use 7k in the front, and 5k in the rear- thats more of a beginning point than an ideal setup, since I dont really need to have amazing performance for just general bashing.

I did notice while on the street w/ my mbx-5 the front tires were balooning quite a bit. Is that due to being on the street more than the diff oil. It was not so bad once in the dirt, but it still un loaded more than I would have liked. If my memory serves I am using 7k in my center diff.

I would step up to 10k, and see how that goes. I usually run traxxas 50k fluid, but I have no idea how that compares to other brand fluid. This is for vehicles that use motor brakes, as I like 4 wheel braking.

A heavier truck would need thicker fluid, but the 8 spider diff should have more gear contact, so it should lock harder than a 6 gear model on the same fluid. I would say to start with 50k and see how that does...

Thanks for the advice lincpimp:mdr:

I use a copper based grease in my centre, BUT, it is a torsen type diff.

http://www.helgerracing.com/j16fioro...lodedpage.html

Awesome diff for truggy/buggy applications.

Then you wouldn't really have to worry about tunning your diff with different weights of silicone, a torsion diff acts the exact opposite of conventional diffs.

Another thing that you can try to control diffing out is tire selection :)

No, you're right. It's basically putting the power to the wheels with the most grip.

However, on my buggy, I do use 5k front, 10k centre & 2-3k rear.