Diff fluid change

[wesplaya]

Hi,

How often should the diff oil be changed? I only bash with my truck on either grass or loose ground if that determines anything. I've heard of some guys changing it most times after a race but i'm sure that would be a bit too meticulous for my needs,

thanks guys

oh and any suggestions of fluid weights for bashing on grass and loose ground with off road grippy tyres...?

[JSY0829]

I usually change mine every gallon of fuel. I have four extra diffs so I have them ready to go at all times. I've been using 30 weight(stock) but going to change to 50 in the front and 30 in back.

[fallonguy]

Mostly you need to check to see if their is oil in them. The diff. can leak a lot of people on here have opened them up and found them dry. 30 weight would be ok for what you are doing. Just remember you can put them back in upside down they are marked as to which side goes up but it's hard to see. I have seen post on here about people end up putting one in up side down and the other right then the wheel go different direction. What I do is mark the top of the diff. with a white paint marker so I can see the top easy.

[wesplaya]

I usually change mine every gallon of fuel. I have four extra diffs so I have them ready to go at all times. I've been using 30 weight(stock) but going to change to 50 in the front and 30 in back.

So what difference/ benefit should it make by increasing the weight to 50k in the front?

[wesplaya]

Mostly you need to check to see if their is oil in them. The diff. can leak a lot of people on here have opened them up and found them dry. 30 weight would be ok for what you are doing. Just remember you can put them back in upside down they are marked as to which side goes up but it's hard to see. I have seen post on here about people end up putting one in up side down and the other right then the wheel go different direction. What I do is mark the top of the diff. with a white paint marker so I can see the top easy.

Thanks for that advice, i'm sure it will prove invaluable when i come to doing it

[Oomp]

So what difference/ benefit should it make by increasing the weight to 50k in the front?

Here is a little info;

Changing front diff fluid directly affects on and off power steering. Thinner fluid will increase initial cornering and off power cornering. On another hand, if you go with thicker front diff fluid you lost initial cornering and off power cornering but gain when exiting corners. This is due by the fact that the inner wheel turns slower than the outer wheel. Thinner diff fluid “frees” the diff action and makes it easier for the diff to turn its two outdrives at different speed.

See what happens when you nail the gas while the front wheels steer left or right. The inner wheel will get the most of the power and will balloon. Thicker diff fluid will “retard” the front inner wheel ballooning effect.

[wesplaya]

Here is a little info;

WOW! Now that's what i call a comprehensive explaination! Think i might experiment with my diff fluids could i get away with filling both diffs with one small bottle of Traxxas diff fluid?

[Oomp]

I prefer to use better quality oils, like Losi, Kyosho, or Xray. I found independent studies that showed that their oils are more accurate and consistent in regard to the weights shown on the labels.

Before ya go putting 50,000 in the rear diff too, please read this;

The rear diff

The rear diff is the easiest one to tune. It should be tuned to be “free” enough to not decrease cornering but it should also be tight enough to prevent the inner wheel from ballooning. At low speed or off power, a rear diff with too heavy fluid will decrease steering because it is harder for the diff to rotate the inner wheel at a different speed of the outer wheel. A too heavy fluid will also make the vehicle fishtail when exiting corner causing over steer.

If you are a basher, I would try 50k in the front, and 30k in the rear.

[wesplaya]

I've already bought a set of Traxxas 10k, 30k and 50k fluids today so i'll try the 50/30 set up for now and see how i get on with it.

Thanks again Oomp! Top guy

[96motorhead]

When i bash I run 40/500/40. when your bashing it never really matters imo.

[detoboy1]

I think I have to disagree with u there Motörhead. Although if may not be as important as it is for racing purposes, but the diffs have a significant impact on the trucks handling. To heavy in the rear and you will just keep on spinning out everywhere etc. diff fluid tuning is one of those things that takes time and patience to find the right combo through trial and observation. Regardless of what ur using the truck for, u will want it to handle at its best.

[revomikey]

I pump mine full of automotive grease and forget about them. I only bash but love the thickness of grease and it won't leak out.

[96motorhead]

Completely agree, but for me when I'm not racing I just run that and it works fine for me. What ever floats your boat is how diff fluid can work.

[detoboy1]

What ever floats your boat is how diff fluid can work.

Your right. All about personal preference

[Thebullit]

Can someone post a link that shows the steps to changing out your diff fluid? I bought a used revo 3.3 and im willing to bet the diff fluid had never been changed or even topped up.

[jordankeis]

its not to hard man just did it for my first time the other day just pull the diffs out bulk heads there is 4 screws on the outer case no fluid in that part just some grease then there is the inner case thats where the fluid should be if any is left lol.... again 4 screws take them out and it just comes apart be careful and hold it so it dosnt just dump all over u if there is anything left..... then just pull the gears out clean out the grime in there and put new stuff in ... then just put it all back together i didnt read how to or watch anything just kinda went at it.... not to hard at all just pay attention when taking it apart

[wesplaya]

Changed mine yesterday and it was easier then i expected to be fair. I did follow a tutorial on youtube but in hind sight, i probably could have done it by myself as long as i paid attention while dismantling as Jordan said. Heres the tutorial i followed: http://www.youtube.com/watch?v=o-ckIT4EOPc