My buggy (Hyper 7 PBS Pro) goes to about 1-2 race meets a month, don't bash it much at home so its not getting a great deal of use.
1 guy at my club rebuilds his Mugen after each meeting with fresh oil for both the diffs and the shocks but he has money to burn, another guy who won the A grade championship last year with a Hyper 8 said only once a season unless it leaks, while the track owner said just check it every 6 months, if it is still clear and topped up just leave it...

?? whats best?

At least once a month to maintain your diff gears.

Since you only race twice a month you should be fine changing them every other month . It also depends on the diff gears material . My Hyper 8 - need to change every two races , My 8IGHT - about once a month .

My Hyper 7 is more than 2 years old raced off and on road and i changed the diff oils 3-4 times...gears look as new!

As long as there is oil in there and it's not THAT old it will be fine.
BUT you have to check them often.
On the center diff it's easy to see if it's leaking...on the rear and front though you have to check them by opening the gear case.

Oil wears out. It may look clear & not leaking but it loses viscosicty.

I changed my diff oil for the first time in 6 months the other day. Was a bit black but still was full to the top. Little strange changing it every 2 race meets.. Seeing 1/1 scale cars only need theres changed every 20,000k and its pretty much the same concept althought the gears are bigger/stronger.


Still waiting for a company to make a buggy that does not need a complete rebuild each time the gears need a reoil.

I changed my diff oil and shock oil every after 2 practice sessions so thats every 2 weeks. And surely before and after a race.,, being on the track and less time in the pit is the main goal here.,,, just my 2 centavoes...thanx!

I just replace it whenever I do a major stripdown. Which is every couple of months depending on the use it gets. If I break something major on the car, or it just really needs stripping right down then I replace it as the cars in bits anyway. Otherwise just watch for leaks

Thats ultra high servicing mate, does it really need to be done that often or does yours leak?
Don't mind changing shock oil, but taking out the diffs and pulling them apart is a tedious and very messy process.

Totally agree!!

if you race a lot you will feel a difference when putting fresh diff oil in.

i change diff oil when wanna racing and not doing that after racing or when bashing

???

hi bozz!,,.No leak here bro., just prevention coz it does cost more to buy a new set of diff gears than the diff or shock oil., yep, taking out the diffs and pulling them apart aint a bother to me. im a newbie.,, just 5 months in this nitro world.....
I enjoy every minute of my rc time. Everything pays off,,., specially winning last sundays local race..,the trophy is there.. a reminder that you get what you put in.

Hi bro, yep youre right. and i race once a month so i gotta maintain to gain...

Had my Hyper 7 PBS for 2 years, bashed and raced it heaps and never once changed the diff oil When it got time to sell I stripped it all apart, the diff gears still looked 100% and the oil still felt good.
Haven't yet bothered to change the oil on my Hyper 8 either and thats had around 10-15 litres through it with 2 different engines, not a problem. I change the shock oil every few months, but a good quality diff oil should last for ages, unless you got a Matrix that leaks

that's true for dyno oils, but for the synthetic oil we use in shocks and diffs it's a whole different story , synthetic oils do not have a oil viscosity index improving additive like the dyno oils do, and in thus synthetic are alot less prone to permanent damage to the viscosity index.