Hello everybody:
I´m a bit dissapointed of still reading complains about R4 diffs, because the eal thing is that that´s a past matter. Since i´ve been running the hard cases, i´ve spente more than 10 L of blend whith the same rear diff, and i´ve had no issues. I agree that Kyosho made a big mistake whith the first design, but soon or late, they´ve solved the problem.
Fot those who wonder if the car is faster than the RRR, i can tell them that at least in Spain (we are 3 Kyosho sponsored drivers), we´ve beaten all our past track records in every track we´ve raced at, and at least me, in my hometrack, i´m 1,5 tenths faster per lap whith the R4. May be R4 is not as relyable as RRR, but concerning the speed, believe me,...is faster.
Are you using the steel crown gears? I bought some recently and they are absolute rubbish. I bought 4 sets at $25 a set and they are only the 2 main crown gears.
Well I ran these at our recent nationals and munched through 4 diffs as they do not mesh properly with the old small bevel gears.
I just got the hard diff cases this week and spent 2 nights trying to build a decent diff. The steel gears just wouldnt work no matter what I tried.
I eventually built the diff with all of the original internals and shimming to get it to be smooth.
I have yet to run the diff yet so I dont know if it will hold up but I have to say after running Kyosho for the last 10 years I am so over the rubbish they have bought out with this car.
If I have diff issues again this weekend I will be selling the lot and moving to a more reliable brand.