Centre diff oil fill or not?
 

I have a Kyosho Inferno and was wondering if it would be beneficial to add some oil to the centre diff. At present it seems to have a thin greasing but its not full of oil.
would this improve things/reliability etc.
At the moment the car is probably a bit too fast & proned to wheelspin of all four wheels.

Carl

RE: Centre diff oil fill or not?
 

You definitely want oil in it. If you haven't already, check your front/rear diff as well. They most likely only have grease as well. Fill the center with something like 7000wt diff oil. The front should have something in the neighborhood of 5000 and the rear should have something around 5000 or maybe 3000 wt. I would think the owner's manual would have a suggestion on what oil to start with.

As it stands right now, I'm guessing you're front tires probably balloon up under heavy acceleration and the rear end is loose. The diff oil will restrict the differential action and send more power to the rear wheels which will improve acceleration and help keep that rear end in line.

RE: Centre diff oil fill or not?
 

Grease won't make it less reliable but you can tune the handling of the buggy buy adding different weight oils to the diff.
Heres some info on diff tuning from the X-Ray Xb8 manual:

Front
Thinner :

increases steering into corners (off-power)
if oil is too thin the steering may become inconsistent, especially it can lose forward traction (and steering) during acceleration out of corners

Thicker:

increases stability into corners during braking
increases steering on-power at corner exit
.................................................. .......... ........................
Center
Thinner:

front wheels unload more during acceleration
decreases on-power steering (reduces oversteer)
easier to drive on rough tracks
if a high-power engine is used you could waste too much power and sometime “cook” the oil in the center diff erential because it “overloads”

Thicker:

more all-wheel drive effect
better acceleration
increases on-power steering (reduces understeer)
better suited on high-bite, smooth tracks
car can be more nervous to drive especially if a high power engine is used - you might need to be smooth on the throttle

.................................................. .......... .........................
Rear
Thinner:

increases cornering traction
increases steering into corner
Thicker:

decreases rear traction while cornering
reduces wheelspin

RE: Centre diff oil fill or not?
 

Try 4-7-2 or 3-5-1 for the Kyosho.

RE: Centre diff oil fill or not?
 

Thanks guys, thats most helpfull.
I'll be popping to my local supplier this weekend for some oils to fill them with.

Cheers Carl

RE: Centre diff oil fill or not?
 

It sound like you have a RTR. check to see haw many spider gears you have in there, I upgrade to 4 in each diff in my truggy, thoroughly cleaned them out and replaced with silicone oil, and wow, what a difference, also keep your eyes on the shimming, to make sure everything is smooth. This is one of the best improvements you can make to your ride, good luck with it

RE: Centre diff oil fill or not?
 

the usual magic combo is 5000/front,7000/center,2000/rear!thats what i would start with. then adjust from there

RE: Centre diff oil fill or not?
 

would this be a typical combo/starting point for any buggy and for any terrain?
I will be doing most of my driving on pavement...

RE: Centre diff oil fill or not?
 

yes its a typical starting point and it what alot of offroad racer use around my area. im not sure for pavement . it give the buggy more front wheel drive

RE: Centre diff oil fill or not?
 

I settled with 5k/10k/3k in my Inferno. Made a huge difference than with the grease it came with. Whatever works for you, only you will know? But rule of thumb as the rest of the guys posted, thickest in the center, then thinner in the front, and thinnest in the rear. You want your rear wheels to unload before your front wheels. You wont push through the turns if you follow this diff lube order. Nice tight turning capabilities this way. Good luck.