They are optional. They do come with the stock kit, but you only use the ones you feel you need. Though the front brace is generally recommended to use.

Thanks,
I think the rear one would be good to have on it... Not so sure the middle one is needed but I have to order the whole set so I guess I'll just put em both on.
I'm waiting to see if the guy I bought it from still has them or ?? He may or may not get back to me..............

Like Kman said, the current gears have a slight curve to the whereas the new gears are completely straight. While helical gears can take more load, we have not found them to be more efficient. We've also found that straight cut gears are more tolerable of imperfect meshes and helical really need a close to perfect mesh.
As for the noise, I can't say that I've noticed or thought about the differences between the two.

Hey everyone,

In regards to the new gears. We have not had any problems with the current gears. They are a little loud, but they are tough as nails and pretty efficient. They are not true straight cut gears however. The current gears were cut on a helical gear machine, but with a 0 degree angle. This makes them as straight as possible, but still not true straight cut.

So we decided to test out some true straight cut gears and found them to be even more efficient, smoother, and quieter than our current gears. It's a minor tweak that will eventually find its way into all of our kits.

As far as helical vs. straight cut, as Matt stated, they can take more load, but they need to be precisely shimmed. The main advantage to helical gears as it relates to RC (IMO) is the ability to fit a larger gear in a smaller place. In other words they are more compact for any given tooth count.

We've always been fans of straight cut gears and all of the major RC companies have switched back to straight cut for 1/8th scale (except AE). The D812, the MBX7, MP9, 8ight, etc all use straight cut gears.

One assembly note on the new gears: The small 5x7x.2mm shim on the diff pinion is no longer needed. The (2x) 13x16x.1mm shims are still needed to shim the differential left/right.

Ah darn it ...

Got any tips when assembling to keep this darn things from shifting? Never had this issue on any other vehicle as much as my SCT410 and EB48.

Are you having to stack shims on one side? That's the only time I had issues. If that's what you are struggling with try sticking the shims to each other with a bit of Loctite before assembly. That helped a bunch on mine.

I used spit having Loctite anywhere near bearings always scares me. Worked great for lubing up the camber links as well.

1 on each side like the manual shows.

When I put the diff into the case, the shim will either flex enough that it doesn't go into the groove or folds over on itself. I am not forcing the shims here either, I go slow to try and line them up and but then I get those issues mentioned.

To me, it feels as if the shims are not very rigid in comparison to others I have used.

maybe I'll try a dab of black grease, see if that helps hold them still during assembly ...

Try adding the cover over one side first. Then slowly rotate the other side closed while holding its shim down with the end of your 5mm hex wrench. Push down on shims if when they start to buckle and continue to close the cover.

I put both over the outdrives (one on each side) and then when you drop it into the case do it one side at a time. It took a couple tries but it wasnt that bad, once it is started it goes in easy its just hard to get it all in there. The one on the 2nd side was sticking out a bit but I was able to slowly push it down enough to get the 2nd half of the case to go over it and that seated them.

I thought it said to put both on one side first, then do one on each side if it was too tight.

exactly.

Well I have had a Tekno 4x4 for 2 months and finally got to run it for the first time and didn't even make it 3 mins and a 5x11mm bearing completely exploded.....So I am wondering are all these bearings lets say" not so good" or do you think I was the lucky winner of the bad bearing.....Should I look into buying a bearing kit for it...Have any of you had problems with keeping bearing in them...I am hoping it was just one bad one....but now my truck is a hybrid cause all they had was Losi bearings.....

Well for me it seems my front bearings started to squeak pretty bad after just two runs through loose dirt (albeit extremely loose and fine clay-like powder which can destroy moving mechanical parts with ease) so I don't think they are necessarily fantastic. But with that said, they still allow my wheels to glide freely without any binding. With that said I don't think they are any better or worse than most rubber-sealed bearings available. Might've just been an unlucky circumstance for you

Replace the 13x16x.1 shims outside the bearing with 8x10x.1 shims between the bearing and the main gear and the bearing and the diff cup. Same effect but they dont get wadded up taking them in and out of the car. The PITA is is you want to change the amount of shim you need to completely disassemble the diff to get them off or add to them. But in reality the shimming doesn't really change once its set.

http://www.amainhobbies.com/advanced...&x=-175&y=-170