Which oil for my diffs?
 

Hi !

I´m building new diffs for my maxx right now and i don´t know which oil i should use if i want to get a good "locking"-effect. (don´t know how the right term is)

Let me say, i don´t want a kind of spool but i want something i have in my real car, let´s say 40%pull/60%push locking...

which weight would be a good choice?

10000, 30000, 50000?

Never used such oil...

And one more question - the ue servosaver is out of stock in every shop i know.

Does somebody sell a saver? Or can somebody help me out get one?

Thanks.

Marc.

Do you have the 6 spyder or 8 spyder diffs?
The 6 takes thicker oil to have same effect as 8 setup.
Are you racing or bashing?
Some like 5k in rear 10 k in front.
I ran 30 k all around with 8 spyder setup. It was a pure bashing setup.
It would climb hills pretty good.

If it are stock diffs you are using, you don't want to use silicone oil. It will leak out and will start drag on your bearings.

With my 8 spider diffs i used 7000 in the rear and 10k in the front

I run the same as well, 10k in the front 7k in the rear.....

Hi there!

I am pulling up this thread as i am actually building the diffs.

Please can you explain to me - why do you use heavier oil in the FRONT than in the rear?

I don´t understand this.

In the real cars world no one would ever even TRY to use a lock diff in the front.

Why is this other in the rc car world?

Marc.

I used a locked diff in front. It made a lot of difference.
The reason for stiffer in front so the front will pull the truck around the curve better.
It really depends on driveing style as well

The thicker oil, as CHC said makes for better handling on the track. It'll pull around a corner instead of sliding, you'll get more traction as the diff action will be less.

yes that is true , it does help pull you thru the corner, that is why you run thicker in the front than the rear

Hmmm, is there an echo in here? LOL

Check Mikes post in this thread:
http://www.rc-monster.com/forum/showthread.php?t=2199

Towards the end of the thread he gives a nice break-down on diff oil selection.

Hope this helps
Daf

Yeah, i searched and find this very interesting reply.

I´m always comparing my rc toys with my real world toys and in real world i HATE front driven cars.

Yes, a front driven car is easy to drive but you can´t steer with throttle.

Even my 911 which has 4WD has no lock in front and push/pull 40/60 lock rear...

So if i am coming out of a corner i hit the pedal and voila the back comes!

And if it´s raining the back comes to fast... :-)

My current emaxx has heavier oil in the front diff tha in the rear diff and i am not able to steer with the throttle. i acts as you describe it - the front pulls the car but the degree of understeering is horrible. Nothing for me.

No way doing a drift with my current emaxx!

But to make it short - please correct me if i am wrong:

Is it correct to a certain kind of degree to transfer the real world experiences to the rc car´s world?

Which means for me: i hate front driven cars, i like rear wheel drive. so the right setup for my emaxx would be heavier weight in the rear than in the front diff.

Correct?

I will now assemble the front diff with 5k oil, the back with 10k oil.

Marc.

P.S.: I Germany we say (The translation will be horrible, i hope you will understand me)

The Definition of understeering/oversteering:

I you CAN SEE the tree you are going to hit in the front of your car - THEN the car is UNDERSTEERING.

If you CAN´T SEE the tree you are going to hit no more through your front window, hmmm, then it was OVERSTEERING.

:-)

Well, not true actually, you are comparing road driving to dirt. If you are running your maxx only on pavement, then your current idea should work. But if you plan on racing on a dirt track, you want the heavier weight in the front.
Also, the reason your back end comes out in the porsche is because it has a slipper type gearing. Meaning more diff action. If one wheel was on the ground, the one in the air would spin. If you put heavier oil in there, then the one on the ground would be more apt to turn as well. But on pavement, you get tons more traction than dirt. It's not that it becomes more front wheel drive, there is still some slppage, just less is all and it allows for more pulling than slipping.

Yes, i know. The ratio of power which goes to back and front is FIX with the standard emaxx tranny. It´s 50/50.

If one uses a center diff the ratio isn´t fix anymore.

The porsche has a fix ratio of power which goes front/back of maybe 20% front/80% back, it is not VARIABLE.

The new 4WD cars have variable ratios of power which goes to front back. The current porsche turbo 997 can send 100% power to the front if neccessary.

So to make it short, every car which has 4WD or even only FWD tends to understeer heavily.

But i think i understand what you mean - if there is some degree of lock in the front diff the car pulls itself through the corner because we are driving in the dirt. one wheel would spin without traction if there wasn´t some degree of locking...

Marc.

The only way to exactly get what you want is to play around with different set-ups.

I hear you about the drifting out of corners, that's what I like too. I tried many diff oil combinations in my cars. Especially in 8th scale buggies, where you have a center diff and the difference in oils is really noticeable, you get a good feel for what does what.

Another thing to think about: the traction physics on an EMaxx are more "dramatic" than on real cars. For example: On-power, you have all the traction in the rear, giving a general (and un-avoidable) tendency to push.

I still like my rear oils thinner than the front, and when the conditions are good (track-surface), my on-power drifts work just fine.

Daf