Diff wt question! Best wts for straight line accel and best turning???

[Dr.J]

I bought some rc best aluminum diff cups and was wondering what weight I should run. In my p4de, I think it was 30k up front and grease in rear, which was a good setup, but with a much stronger brushless system in a heavier maxx, i didnt know if these factors would change how I would set it up. I would like to limit "diffing out" on hard accelerations, but I really want a good turning ability. Any ideas from some experienced runners would be appreciated! BTW, when taking my diffs apart, I realized they werent the hd ones w the extra bracing, and the plastic cup was getting pretty tore up.

[danielhr77]

I use 50wt from Traxxas...

[Dr.J]

Im thinking heavier up front, around 30-50k, and grease or 5-10k in rear??? Im just trying to wrap my head around how it translates to how it functions. Heavier upfront makes he think when turning youd get alittle less slipping to the inside tire, causing better turning since the outside tire will pull it thru the turn better. Maybe alittle more than grease in rear to help stabilize straight line torque??? Am I thinking of this wrong?

[M n M]

Dr J, from my understanding you are on the right track.

Thicker oil doesn't let the power transfer to the side that is breaking traction. In this case we are talking about turning. And in speed turns the inside tire(s) is the one that looses traction due to chassis role. With thin oil the power would be sent more to the inside.

On straight runs with thin oil the power is sent more to the side that has the ring gear I believe, which can cause fish tails and the rearend to kick out.

Too thick oil or locking the diff can make it difficult to handle in turns because then the outside tire(s) can't spin faster than the inside as it should.

At least thats how I understand it.

I'm not even using oil. I tried and like a 100% silicone plumber paste. I couldn't even tell you what kind of weight it is. It's paste so it doen't even pour. It works well for me. The wheels will still "diff out" under the right (or wrong) situation.

[MITCH316]

I run 50K front and 30K rear...it works well for me. Even 50K all round is OK.

What I noticed was the thinner lube in the rear handles well at high speed runs and allowed for better traction control when racing on dirt tracks.

I recently tried 120K diff lock and it was horrible. I broke 2 ring gears on the rear in 2 days. For the way I using my truck it wasn't the way to go for me. On 6s the truck had to much power and under full acceleration the truck was hard to handle and wanted to spin out. I think if you were just a basher 120K diff lock, the right gearing and 4s, it would be awesome.

I like to use my truck for a bit of everything from racing on track, to skate park bashing or tearing up the grass. My truck handle like a beast. I am runnging HPI GT2 tyres on maxaimizer 1/2" offset beadlock rims.

The way I understand this is:
The thicker the oil (less viscous) - it allows for less slip (IMO...In the rear, better for low speed application where you want more power in the rear and traction [great for rock climbers]) I could see it working well for low speed bashing

The thinner the oil (more viscous) - it allows for more slip (IMO...In the rear, better for racing and high speed) with a thicker oil in front helps with pulling power where you notice this in the turns more

Again...its one of those trial and error cases where you need to see what works best for you.

[Dr.J]

Ok, thanks for confirming this. Ive ordered 50k for front and grease for rear to start. Ill also get to see how the rc best aluminum diff cups work out. They have a brass fitting in them and were only $30 shipped for 2 from ebay.