Ive ran close to a gallon through my Kyosho STR since ive had it and i was just lookin it over tightening everything up cleaning it etc and i open up the front end and i see that my drivegear is all chewed up as well as the gear on the front differential. I opened up the rear and it is fine. Where did i go wrong? Why would my front gear be all chewed up and not the rear, is it shims? This is my first time building a truggy, could this happen from not having enough shims between the diff and the diff case? Ive ordered new gears but before i reinstall them and chew em up again id like to know if anyone has any ideas as to why this happened and how i can prevent it in the future.

Vj


Heres a pick of what it looks like.

My guess would be the problem lies in the center diff. It's unloading the rear and sending too much power out front. Shims would certainly help but I'd start with thickening up the center diff fluid.

Ok, im gonna go get new diff oil tonight, but im fairly new to the hobbie so please take that in consideration if my questions seem nuby.

Right now im runing the diff oil that came with the STR kit which is Front = 4000wt Center = 7000wt Rear = 3000wt.

Now a racer i know runs Front 10,000 Center 20,000 and Rear 3,000 does this seem like a good combination, the only reason i question is because the weight seem alot different in the front and center than what came with the kit. What hes doing is basicly sending more power out to the rear tires with this combination correct? Do you think thats to much for the front and center? Sorry for all the questions but thank you for the help.

Where did you go wrong ?

By building the truck without checking out this site first :-) j/k ....

Lots of ST-r related info's and building and diff shimming techniques here:

http://www.truggyracers.com/forum/in...?showforum=117

Good stuff ty

I read the review on the Mugen MBX5T in XRC and the diff fluids they came up with are way different than what came in the kit. I'd say the stuff in the kit makes for a good starting point. I set my Mugen up with the 5000,2000,2000 that cam in the kit but I'm more than positive that will change.

Ok just finished replacing the gears in the front diff it took 4 shims on each side of it for just a small amount of play, but i have 1 more question.

When i removed the old diff fluid it was a "silver" color no longer clear, is this anything to be alarmed about it was the same in the front center and rear.

BTW i went with the 10k front 20k center 3k rear well see how it works out on Saturday

O yea also how often do you open up your diff cases and re-lube, when i spoke with Tim at kyosho he said that a gallon was alot to run through the truggy without opening up and relubing the diff gears.

That silver is all the metal shaving from the chewed gears, smae happens in shocks, nothing to worry about. I will be re-building my diff's in my ST-R this weekend and will, i assume, find similar issues as you. Have 2 gallons in mine so it lasted longer than most but not as long as it should

I will probobly run 10k front 15k 3k rear, I ran with stock as well, was prtty good for me so dont plan a drastic change, so yer setup should be good

stav

Awesome thank you!

I run 10/30/3, works great. Your shims were probably a little off, that is what mostly causes that.