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Metal axle housings on SMT10? Bad idea?

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I have an SMT10 incoming, as the most recent sale in the US brought them down to just $110 (and approximately £120 with shipping to the UK!)... Well, hopefully incoming, provided I don't have the same export/import dramas as @Mad Ax's LMT given I also ordered from Amain!

I have been thinking about adding "beef tubes" into the axles to help with reliability, but I also have some full metal axle housings from a stalled crawler project that I could use.

Given some of the drivetrain weaknesses with the SMT10, is this a bad idea to add a bunch of extra weight in the form of metal housings? Anyone have thoughts/experience on this (maybe @87lc2)? Really appreciate any thoughts.

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Hey @frameskip that's a good question and it depends entirely on what you're going to do with the truck and what will power it.  As far as metal housings alone, I use them on crawlers often but rarely monster trucks.  There's better ways to get weight down low in a monster and it's way better off being sprung weight than unsprung weight.  You really want the axles light and the lower part of the chassis heavy for the best performance. 

I've driven my SMTs a lot over the past 2-3 years and I've revised my thinking on the SMT drivetrain a bit.  The transmission is fantastic since they updated to metal gears.  I run my slippers locked and never a single tranmission issue.  As far as axles, diff gears have been great but I've gone through a lot of ring & pinion gears.  When I build a new one these days I just swap in Axial or Vanquish HD gearsets and call it a day, the stockers will get destroyed under brushless power even when shimmed properly.  Front survive a lot longer than rears so just swapping the rear is an option and save the stock rear for the front if it wears out.  On my race trucks everything else is left stock; plastic housings, rear lockouts, c-hubs, and knuckles.  No issues with the stock plastic parts at all and have never broken any of them.  

Not sure if that answer your question but hopefully it was helpful in some way.  If you're not racing the truck and going to use it in a scalish manner then the metal housing will be fine.  Over power or over drive the truck and you'll probably break some parts, especially if you're running Clod sized wheels/tires.  If running 2.2 monster tires you'll be better off.  One thing is for sure, if you run metal housings you'll need limiting straps to save the stock shocks.  I usually don't run straps on my SMTs but if I was running a metal axle housing I definitely would. 

 

 

 

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Thanks for the detailed response -- really helpful. I'm actually having a bit of a facepalm moment, as I had completely overlooked the unsprung weight issue (even worse as there's a stock Clod across the room looking right at me :D):

13 minutes ago, 87lc2 said:

There's better ways to get weight down low in a monster and it's way better off being sprung weight than unsprung weight.

With your overall advice in mind, I'll probably just opt to run the stock plastics on on 2.2 tires on 2s with a sensorless HW 3652 (3300kV) I already have. I don't think it'll be flexing that motor very much, as it will probably have a relatively sedate life trundling around the garden with the kids (small/scale jumps at most).

Thanks for the tip on the ring/pinion gears -- somehow I had assumed it was the bevel gears that would fail. I have a hardened stock ratio set in my metal axles (although cheaper Boom Racing parts if I remember correctly), so I might just swap them into the SMT10 housings. If they go bad I'll just pick up the Axial/Vanquish parts on the next go around.

Another question if you don't mind -- regarding locking the transmission, are you running a slipper eliminator, or just cranking down the existing slipper very tightly?

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With that power setup and stock sized tires you will be just fine, even with stock ring/pinion gears.  I really only strip them when running Clod sized tires on 3800+kv motors.  The HD gears are pretty expensive, so don't bother getting them unless you need them, I think you'll be fine. 

The first run of these had terrible bevel diff gears and they broke all the time.  That has since been fixed, have not broken any of those at any power level in the past 2-3 years.  Of course now that I've said that all of my trucks will break them immediately :) 

I just crank the stock slipper down all the way, no need for a slipper delete as far as I know.  I haven't had one slip yet with the nut cranked down tight.  

Anything else just ask, love talking RC monsters. 

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2 hours ago, frameskip said:

With your overall advice in mind, I'll probably just opt to run the stock plastics on on 2.2 tires on 2s with a sensorless HW 3652 (3300kV)

I run a 3000KV Onyx system on  2s most of the time and a occasionally 3s blasts. 
much like your plans I do some garden bashing and simulated scale freestyle/ jumping. I kept 2.2 on it and all stock plastics. The only things I have stripped out were a wheel hex that wasn’t tightened properly on 3S. 
I think mostly the stock drivetrain holds up well unless you are racing or running clod sized rubber 

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6 hours ago, frameskip said:

 

I have an SMT10 incoming, as the most recent sale in the US brought them down to just $110

 

Where ? !
I see the builders kit on a lot of US sites of $199, but no $110 

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1 minute ago, Dakratfink said:

Where ? !
I see the builders kit on a lot of US sites of $199, but no $110 

They had a week long sale from Mid April to April 22nd that was $90 off the builders kit (Amain, Tower, Horizon - pretty much all online shops) for the SMT.  I got a couple more kits for parts.  At $110 for a kit the parts are worth way more than that, just a set of AR60s goes for about $100 these days. 

The Losi was on sale again at the same time for $140 off.   I have a feeling they'll do it again, they've done it twice in the past 3 months or so now.  I'll post if I see it. 

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I think may have gotten a sale notice in my email from Tower or A Main and ignored it. 
then again, I was closing on a home purchase the day the sale ended so I might have been distracted, lol. 
 

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1 minute ago, Dakratfink said:

I think may have gotten a sale notice in my email from Tower or A Main and ignored it. 
then again, I was closing on a home purchase the day the sale ended so I might have been distracted, lol. 
 

Hard to think about spending money on toys with that going on :)    

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