GIHOSU

iTrader: (5)

Just wondering, are the 3 gear transmissions that you guys see used more in 17.5 or Mod?

Tonight I got a peek at my 2nd new to me SC6, I found another peach.

rbk1115

iTrader: (3)

I see the 3 gear transmission used equally in 17.5 and mod here at SDRC.

rbk1115

iTrader: (3)

I wanted to provide an update on the stripped idler gears problem I have been having. My most recent transmission build with 2x plastic idler gears (UMW513) failed yesterday. Both idler gears were stripped. The one closest to my Schelle Top Shaft took the most damage. I got about 40 packs and about 3-4 race days through this transmission build. I run a Reedy 8.0T motor on a medium to high bite surface. The current track layout at SDRC has quite a few bigger jumps that the previous layout that might have aided in the failure. I ended up rebuilding the transmission utilizing 1x plastic idler gear (UMW513) and 1x aluminum idler gear (UMW718) because I did not have any spares on hand and SDRC only had these in stock. A few rebuilds ago, I noticed that my aluminum idler gear was severely worn out and I went 2x plastic idler gears instead. I still had the old aluminum gear and when comparing it to the brand new one aluminum, it was a night and day difference. I used the old aluminum gear for about 9 months. We'll see how long this rebuild will last. It will be good to have some data on which setup lasts longer.

GIHOSU

iTrader: (5)

Thanks for the observation, I appreciate it.

I guess I am patiently waiting for Kyosho to release a 3 gear tranny...

twindad98

iTrader: (20)

I have had my share of idler gear problems. I just rebuilt the trans in my RB6 and SC6. The RB6 was getting noisy so I took it apart and the plastic idler was almost worn sharp ( I use one plastic one aluminum idler gears). It was on it's way to failure.
I replaced the plastic gear in the SC6 because I did strip it out. Now that I'm using the aluminum/plastic gear set up, when it does strip, it most of the time takes out the diff gear also.
I can get about 8-10 race days safely out of the idler gear. I have though about just keeping track of it and changing the gear about every 2 months. Kind of stinks that I have to worry about it but if it make the truck more reliable I guess I'm ok with it. It will cost me about $5 every 2 months to change the gear out.
Also I have seen a drastic improvement when I use the plastic/aluminum setup. The transmission does last a lot longer. I run mod with all my Kyosho vehicles.

rbk1115

iTrader: (3)

Great information! When the transmission gets noisy, it is a sign that the teeth on the gears are worn sharp and are about to break. That is interesting that you had the differential gear strip out with the use of the aluminum/plastic idler gear combo. I have never had the differential gear strip out with all the idler gear issues I have had. With the aluminum/plastic combo, it would appear that the plastic idler gear is the weakest point. In the data I have gathered, I suspect that aluminum gear will last about 6-9 months before it has to be replaced. During this time, the plastic one might strip out, but it just depends.

Do you use any lubrication on the gears inside the transmission? If so, what do you use? For my most recent build, I cleaned everything and used a little white lithium grease. The transmission is smooth and quiet.

Bartman42

iTrader: (44)

Me either and I've stripped a lot of them lol

GIHOSU

iTrader: (5)

My tranny in the truck I got from a buddy was good for about 4 months of Mod racing. When it went it had SP black plastic gears and the one that runs on the diff gear lost 1/3 of its teeth and the diff gear was damaged too. I replaced the 2 gears and it has been good since. I have had a 17.5 in it lately so it isn't getting beat up too badly now.

twindad98

iTrader: (20)

When I was running just the plastic idlers it would always take out the one at the diff. Now that the aluminum gear is at the diff it's always the one at the top shaft. I guess the aluminum gear will pass the plastic pieces down to the diff.
I'm only running a 9.5 in the truck. And yes I do use some grease on the gears. I usually use some kind of black grease, just a little bit. It does seem to help with the longevity of the gears. I have tried running them dry and they do wear out a lot faster.
I have my 3 gear cases modified to run mid motor but I haven't purchased the spacers I need. I hoping that will help cure some of the idler gear issues.

Bartman42

iTrader: (44)

What's the hold up . We need your feedback on how it feels

twindad98

iTrader: (20)

We had a trophy race over the weekend and one of the local Kyosho guys had a 3 gear transmission and he said that it was a lot more peppy.

Bartman42

iTrader: (44)

Was he running stock or mod? Did he say anything about loosing forward bite?

Kings Kid

iTrader: (35)

I just completed the mod in my sc6 for stock. Was quicker on acceleration, I was able to gear up a bit. Didn' t notice a loss in forward bite but only had time for one pack. I' ll test it more next week.....

twindad98

iTrader: (20)

He was running mod and he said that he didn't notice any loss in forward bite.

twindad98

iTrader: (20)

He was pulling wheelies mid way down the straight it looked pretty planted to me.
Forgot to mention that it was in a RB6. But I still think that the results will be very similar.