I fixed the tranny but i want more

[bigboystoysguy]

hey guys
i fixed my tranny with a foc and i did it in all aluminum. i also have the gear that goes on the shaft right behind the 2 speed in aluminum. now thats all fine and dandy but it still seems a little fragile. i was wondering if any one knew of an all metal gear tranny. i want the 2 speed and the gears that the spur conects to in alu as well, or better titanium. so if any one knows where i can get an all metal gear tranny, links would be excellent. oh ya one more thing i heard was that with big block power i could flex the plastic tranny case and cause the gear mesh inside the tranny to come outa wack and strip stuff. should i upgrade to a metal tranny case too??

 

[SkyMaxx]

I would seriously reconsider using aluminum or titanium as gears within the tranny. Aluminum is relatively soft for a gear in that environment, and titanium has a rather low tolerance for shearing motions which occur frequently when gears interact.

Aside from that, RRP makes some nice gear sets for the transmission. Look here:
http://www.robinsonracing.com/catalog/traxxas.html#trannygears

As for flexing the plastic tranny case, that is a new one on me. You'd have to do some serious work to flex the tranny case or deform it in any way.

 

[bigboystoysguy]

I have the foc #8585 and the #8528 and I didn’t know a bout the #8525 top shaft I'm going to order that later to day. what about the main 2speed gears. the tranny flexing wasn't a big worry i just heard of it and thought i would bring it up.

 

[SkyMaxx]

Not having done the FOC on my T-Maxx, I'm going to have to let someone else answer up on that question. I know that they make them, just not sure which part number it would be.

 

[bigboystoysguy]

ok, thanks for the help on the other numbers!!

 

[SkyMaxx]

I would recommend doing a search on this site for this topic. I know that you are not the first person to want all metal gears within their tranny. I also know that the question has been asked and answered with links to where you can obtain the gears in question.

 

[bigboystoysguy]

hey sky, you said i should realy reconsider using alu or ti gears, i was wondering why?? thats what everyone recomended was the alu.

 

[Willthethrill]

i think the tranny case that is alum looks pretty dang cool, so if you have the $, go for it!!

 

[Domination]

he already said why because Aluminum is a soft metal and i would doubt it would hole up with the abuse a tranny take

and he said not TI because it has a low tolerence (i have no comment on that because i dont know)

But i do agree on the RRP steel gears for the tranny spur and even the CB if you want

 

[SkyMaxx]

Originally posted by SkyMaxx
I would seriously reconsider using aluminum or titanium as gears within the tranny. Aluminum is relatively soft for a gear in that environment, and titanium has a rather low tolerance for shearing motions which occur frequently when gears interact.
...

Here is the reason I posted earlier. I noticed that RRP lists a set of "hardened" aluminum gears. I'm not quite certain what that does to the strength of the aluminum, but it still remains a soft metal when compared to hardened steel.

Here's what you get with aluminum or titanium gears:
1. Lighter weight means lower rotational mass. This means the tranny will spin up quickly and tend to slow down just as quickly.
2. Aluminum is soft and could get ripped up pretty quickly if your drive train binds on anything while under power from that engine. Titanium tends to be brittle and actually shatters before it bends. This means that titanium has a high tensile strength (ie resists bending and stretching type forces) but a low shear strength (ie sudden tangential forces like the type gear edges tend to put on each other when a sudden load is applied like slamming on the gas and getting a rapid engagement of the drive train).

Don't get me wrong. Metal gears are a good upgrade. You just need to think through what it is you want.

Steel and hardened steel buys you the following:
1. Heavier weight with a higher rotational mass. This means it takes a little to spin them up, but once running they will staying running a bit after you let off the gas. Nice for coasting as it maintains the speed for a little longer.
2. Strength. Steel is not as strong as titanium when it comes to bending forces, but it has a much higher shear strength than either aluminum or titanium. This means you will be less likely to loose teeth off the steel gear that you would from the aluminum or titanium gear.

So...it is really up to you. I give you the engineers answer to your question. You decide where you want to put your money. The aluminum and titanium are stronger than plastic. The steel and hardened steel are stronger than both when it comes to gears.

 

[woody]

Two words Guys: Unlimited Engineering!!!!!!!!
:sheep:

 

[bigboystoysguy]

ok. thanks sky, its just everyone told me to do aluminum for the wieght factor. i know alu is soft especialy if its not hardened and i thought steal would be to heavy but now you bring up the strength of steel and the coasting efect. i allready installed the alu by rrp, but now i might order the steel. whats at ue woody??

 

[olds97_lss]

Unlimited Engineering has lightened steel trans gears. I have yet to find anyone selling the 2 speed gears in anything but plastic.

As for the aluminum trans case, i bought it to help prevent chassis flex, not trans case flex. When I would grab a finger full of brake, you could see the spur move about 1-2mm. This isn't much, but considering i just put on a $30 RRP spur, i wanted to do everything i could to protect it. Now chassis flex is non-existent.

I also run with full RRP steel trans gears (as full as you can get). It does spool up a little slower. I would rather suffer a bit at the line, then not make it through a day of beating the crap out of it due to a ripped up gear.

Just my .02

 

[Çh®i§tiªñ]

I never had a problem with the alum gears.

However, when I built my Cybermaxx, I went all hardened steel where possible. And the topshaft as well as FOC. Didnt seem all that much heavier when I was building it. I also picked up a billet tranny case which I dont think will ever flex. Maybe dent, but I dont think it will flex.

All in all, if you are insane on your ride, I would suggest the hardened steel. If you are a moderate basher, I see no reason the alum wouldnt work for you.

Titanium gears??? Never ran them.