210 Gear Diff Setup.

[andys]

I'm going to try my 210 indoors at the next Worksop.

Should I be running the Gear or Ball diff - if geared which oil?

What's the difference in handling between the 2 on this kind of surface?
Cheers.

[AmiSMB]

I would use the gear diff if racing on high traction carpet/cork indoors. If their is any slippery sections then you will need to be very careful on the throttle but then you can make up for it on the carpet/cork sections. Maybe start with the same as Chris Doughty and put 5000 in the diff as that is what he uses for Worksop.

[andys]

Thanks for the info
Will put in the Geared Diff with 5000 to start with.

Andy

[Chris Doughty]

I only used gear diff for the first 2 meetings at worksop.

ball diff is BY FAR the best thing to run at worksop in 2WD.

all of my setups from last year should be on the TD website.
this is probably the best starting setup to look at
http://www.team-durango.com/pdf/setu...24_02_2013.pdf

Tires make a HUGE difference there, I would highly recommend running almost worn-out mini-pins up front and rear tires that have had 1-2 heats on carpet to scrub them in ready.

[andys]

Hi Chris.

Thanks for the info - i'll check out the setup you posted and begin from there

A few friends were running Geared Diffs this weekend and their cars looked to go really well (Yokomo Bmax) whereas mine with the Ball Diff seemed off the pace?

Is this your personal preference - or do most of the top drivers favour the ball diff at Worksop?

[Chris Doughty]

its my personal findings.

with the Gear diff, I find that when I get on the power the car does not want to square up, it always want to continue to rotate and not drive out the corner straight.

on high grip like carpet then this is a really good thing, helps cut nice arc's existing the corners.

on low grip where you want to get out of the corner without the car over-rotating this is a bad thing.

so... if your car had too much rear traction on power, the gear diff would work well for you.

but typically, going to worksop with 2WD, everyone is searching for rear end grip in 2WD, especially on-power, this is why I didn't like the gear diff

[Bells]

I'm confused both my son and me have run a gear diff and ball diff at batley indoors and cullingworth , currently both ball diff , a lot of racing friends have said a ball diff for slippy floors is the way to go , but we were both quicker with a gear diff ! We ran 1 shaft and 2 gears and 700 shock oil in them , the rtr 210 comes with a gear diff and rear motor and the demo vid shows it on slippy dirt , aren't the idea of rear motor and gear diff contradicting each other ? Anyhow I'm building 2 more cars with gear diffs so we can try both at the same meeting

[Fabs]

I concur with Chris,

I tried the geared diff on saturday and my car was near undriveable. With a ball diff it was much better. I plan on trying different oil setups but so far I've tried it twice on slippy floor and took it out immediately both times.

As for the RTR, a ball diff would require adjusting from the factory and frequent rebuilds for the customer, which isn't really ideal. This is why there's a geared diff, it only needs to be built correctly, no skill/knowledge involved in the setting up process.

Fabs

[Danosborne6661]

Running really light oil in a geared diff seems wrong. Anything lighter than 5000 is so easy to diff out on an on-power sweeper, the diff action is WAYYY too light and the car will always want to rotate on power.

What Chris is saying about the geared diff wanting to rotate on power is right. Although... if you thicken the oil even more that should straighten it up on power. For example, the oil supplied with the Schumacher KF is 12,000! 5,000 is the very lightest I'd want to put in the DEX210, I would personally be looking at 7000 and upwards!

[Jason A]

Hi Andy,

My experiance at Worksop running the DEX210 is the same as Chris and Fabians.

I first run the DEX210 with a geared diff in with 1k oil and it was so hard to get the power down without the car wanting to swop ends.

I then ran the second meeting with a ball diff in and the car was so much better coming out of corners and on to power.

Another thing you will find at Worksop is the grip level gets a lot better when the heating is on in the hall and when its off the grip drops out.

I am sure with a bit of looking at the setup sheets of some of the Team Durango drivers that drive at Worksop regular you will find a good setup that will work for yourself as well.

[Danosborne6661]

Light gear diff oil = Loads of steering on power
Heavier gear diff oil = Car will try and push a little more on power and not loop out.

Start with 7,000

[DynaMight]

I've recently ordered some oil for my diff, but now I'm wondering if I ordered the correct stuff. I know wt and cst is competely different but when I saw 5000 mentioned assumed it meant cst.

When we say 5000wt, do we mean 5000cst or actual 5000wt (like 150,000cst according to a rough calculator I found)



Also does anyone know what oil is fitted from factory in a 210 RTR?

[Danosborne6661]

I would recommend 7,000CST, which I suppose is the equivilent to 700wt oil. I would personally go thicker but it would be a good starting point for you. Anything lighter rotates too much when you're trying to get on the power.

http://www.racing-cars.com/pp/Manufa..._RC/CR221.html

[av4625]

i wouldnt recommend going as heavy as that in the oil for a gear diff, the car will only straighten up and push a little with heavier diff oil if the grip is there, if the grip isnt there it is more like a solid drive and the car will spin out like chris experienced,

i sometimes run on polished wooden floor with dBoots nanobyte B compound, at the start of the night, when its dusty a ball diff is much better, but when the grip comes up the geared diff is awesome, you get more punch out of the corner, i run 2k in my gear diff, so that i still can get rear grip as its still polished wooden floor at the end of the day, running mid motor btw

jorn used too run 650 shock oil in his geared diff, not sure what he currently runs,

i really like 2k in the geared diff for astro, wooden floor and anywhere really!

[Chris Doughty]

when it comes to diff oil, I think most things are actually CST rated.

its just a lot of us refer that refer to shock oil as 'wt' also then just say the diff oil as 'wt' too.

RTR from the factory is 3000cst oil, but this is with 2-gears inside the gear diff so it will feel comparatively 'thinner'

Overall, there is no substitute for trying it for yourself and going with what you like on your own track.

at Worksop I ran a ball diff, at Maritime I ran a a very thin gear diff because it made the car do what I wanted it to do on that track.

The diff of a 2WD car is a HUGE thing and the optimum setup for this part will not be the same for 2 different drivers.

[Chris Doughty]

Just to throw some more things into the mix. you can also change the o-ring hardness for the diff seals. this makes a difference too! (I've not tested this)

http://www.team-durango.com/search.p...ring+p-4&Go=Go

[wes]

As Chris said choice of diff and oil are down to personal preference. Have run a gear diff with oil in range of 1000-2000wt on carpet for last couple of years, have stuck with ball diff for all other surfaces which seems to be a good starting point.
Remember due to how a gear diff works (squeezing oil between gear teeth) the design and tolerance varies greatly between manufacturers and so its not really sensible to compare oil rates used in different cars.

[DynaMight]

Cheers guys. I had already purchased 5000cst and I have never changed it, so 3000cst already in there. I'll see how it goes, maybe try something thinner like 1000cst at some stage and see how the three compare, if I'm even able to tell with my limited skills

[DynaMight]

Well took apart the diff tonight, first thing I noticed was the thing was literally bone dry! no actual build up of oil, although thankfully the diff gears were 'moist'

Then I noticed that I only had one set of gears, whereas the guide on the Durango website shows two sets!

Heres a pic, just after I opened it. Slightly dark as from my phone:


Official shows it like this:




Anyone know if this is just an RTR thing? maybe older design. Any drawbacks? and how long should the oil remain the diff!! assuming Durango even filled it up properly in the factory!

[rcjunky]

2 gears is correct, the gear diff seperatly has 4, its stronger that way. I'd get the new plastic set and throw that in there. Not sure what they normally put in them out of the box, clearly not much.