Differential Questions

[D-Dub]

I've run about 5 packs through this crawler since I built it from a kit.

Yesterday I decided to check the diff play and inspect the wear, I found my sun gear on front and rear have chunks missing, and my grease was a nice sparkly silver paste.

I shimmed them and used the stock grease when I first built them. I cleaned them off, and re-lubed them with some lucas X-tra heavy duty (what I have on all my bashers), just ran another pack through, and the diffs are toast. More wear after just one run.

Is this a common thing with these stock gears?

I am running the mamba X sensored 2850kv with drag brake off for the first few packs and at 10% for the last two packs. Could the drag brake have caused the massive wear to the diffs? The metal they are made of seems really cheap compared to my bashers.

Seeing as my non-sealed bearings are probably going to die soon by being exposed to that contaminated grease, and my gears are not going to last much longer.

Can anyone recommend any portal axles around the $100-$200 price range?

Either complete bolt on portal axles, or maybe something that adapts to the stock axles, and some better diff gears?

Looking at reviews online, nothing seems to be very good under the $200 price range?

[smc-93]

If you're not concerned about keeping it in the family, I'd recommend TRX portals. I no longer run them on my "4" (just for scale appearance) but I've seen numerous videos about just how much abuse they can take.
Most of the AR44 conversions I've seen like the RC4WD (~$220 for both axles -shipping) also don't offer any gear reduction like the TRX axles. IMO, portals are useless without any gear reduction. You only get a minor increase in clearance while raising your COG and adding potential failure point.


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[D-Dub]

Hmm, ok, maybe ill just look for some stronger gears for now.

Anyone have a part number for the heavy duty AX44 gears for the SCX10 2? I see a couple different ones.

I have the SCX10 2 raw builders kit.

[vinnieb729]

where did you shim them? I typically put a Traxxas PTFE washer (#TRA1985 5x8x0.5mm) on the pinion before installing the driveshaft. Keeps the pinion from getting pushed into the ring gear.

[smc-93]

Originally Posted by D-Dub

Hmm, ok, maybe ill just look for some stronger gears for now.

Anyone have a part number for the heavy duty AX44 gears for the SCX10 2? I see a couple different ones.

I have the SCX10 2 raw builders kit.

There's several options to pick from on Amain hobbies (just searched scx10 gears, so very broad results https://www.amainhobbies.com/search?cID=&s=scx10+gears) Only a few are labeled "heavy duty" but I think most of the after market options will be more durable then the factory gears.
The only gears I have experience with are the RBK factory gears, haven't put much run time on them. And the SSD Pro44 gears (which I'm 99% are compatible with the AR44 housing). I've run these a decent amount, 3-4 2s packs and 1-2 3s packs, and haven't had any obvious issues.
I haven't disassembled the Pro44 (Trail King, 35t brushed motor, 3s) axles for a close visual inspection yet but I only applied minimal grease (ran out, too impatient to wait for more) and they still run super smooth. They felt like they were much nicer quality than the axial AR44 gears.

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[D-Dub]

Originally Posted by vinnieb729

where did you shim them? I typically put a Traxxas PTFE washer (#TRA1985 5x8x0.5mm) on the pinion before installing the driveshaft. Keeps the pinion from getting pushed into the ring gear.

I shimmed the pinion the same as you, and the ring on one side, as it had a lot of play side to side.

[DRED805]

Originally Posted by D-Dub

Can anyone recommend any portal axles around the $100-$200 price range?

Either complete bolt on portal axles, or maybe something that adapts to the stock axles, and some better diff gears?

Looking at reviews online, nothing seems to be very good under the $200 price range?

I put some kyx portals under my SCX10 II last week. I've had them for a couple months but was afraid they'd be garbage, so I never took them out of the package. That was a mistake. I'm stoked on them so far.

I swapped in my rear differential with vanquish underdrive gears, with no problems. Same size bearings and everything. I ran the truck hard for 8+ hours over the weekend, and I have absolutely no regrets. So impressed I ordered some kyx all metal AR60 axles for another build.

At ~$180 for a set of complete axles, I'd say it's worth a try if you've got budget in mind.

Looks like they'll be on sale for $160 on the 21st...

https://www.aliexpress.com/item/4000...1ea318ac1fe0-2

[D-Dub]

Update: I emailed Axial product support with pictures and they agreed that the gears do have odd wear and are going to send me replacements.



https://photos.app.goo.gl/HRX57te17YtvZDtS7

[D-Dub]

Originally Posted by DRED805

I put some kyx portals under my SCX10 II last week. I've had them for a couple months but was afraid they'd be garbage, so I never took them out of the package. That was a mistake. I'm stoked on them so far.

I swapped in my rear differential with vanquish underdrive gears, with no problems. Same size bearings and everything. I ran the truck hard for 8+ hours over the weekend, and I have absolutely no regrets. So impressed I ordered some kyx all metal AR60 axles for another build.

At ~$180 for a set of complete axles, I'd say it's worth a try if you've got budget in mind.

Looks like they'll be on sale for $160 on the 21st...

https://www.aliexpress.com/item/4000...1ea318ac1fe0-2

I actually have KYX shocks and really like them, except for the fact that one of my spring retainers came off while driving.

Ill keep those in mind thanks!

[D-Dub]

Originally Posted by smc-93

There's several options to pick from on Amain hobbies (just searched scx10 gears, so very broad results https://www.amainhobbies.com/search?cID=&s=scx10+gears) Only a few are labeled "heavy duty" but I think most of the after market options will be more durable then the factory gears.
The only gears I have experience with are the RBK factory gears, haven't put much run time on them. And the SSD Pro44 gears (which I'm 99% are compatible with the AR44 housing). I've run these a decent amount, 3-4 2s packs and 1-2 3s packs, and haven't had any obvious issues.
I haven't disassembled the Pro44 (Trail King, 35t brushed motor, 3s) axles for a close visual inspection yet but I only applied minimal grease (ran out, too impatient to wait for more) and they still run super smooth. They felt like they were much nicer quality than the axial AR44 gears.

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Do the ones that bolt together come with the center piece they bolt to? That is where I don't understand how they say they fit, when mine are not just a ring and pinion, they have a middle to the ring gear.

[smc-93]

I've seen those KYX axles floating around on Amazon, good price for all metal axles. It looks like the portals are still 1:1 like the RC4WD conversion though.

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[smc-93]

Originally Posted by D-Dub

Do the ones that bolt together come with the center piece they bolt to? That is where I don't understand how they say they fit, when mine are not just a ring and pinion, they have a middle to the ring gear.

No the (with the SSD gears at least) locker comes separately. You'd have to make sure you got 6 bolt gears and the matching 6 bolt locker if you go that route.
https://www.amainhobbies.com/ssd-rc-...aztakqhb2xactz
https://www.amainhobbies.com/ssd-rc-...alt2qayc2xactz
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[DRED805]

Originally Posted by smc-93

I've seen those KYX axles floating around on Amazon, good price for all metal axles. It looks like the portals are still 1:1 like the RC4WD conversion though.

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Correct. I was hoping there'd be some gear reduction in the portals, but they're two 16 tooth gears. Still worth it.

[Fricker08]

Originally Posted by D-Dub

Do the ones that bolt together come with the center piece they bolt to? That is where I don't understand how they say they fit, when mine are not just a ring and pinion, they have a middle to the ring gear.

If you buy aftermarket ring and pinion gears, you’ll need what they call the spool or locker that the ring bolts to. Ssd 10% overdrive gears for the front and some standard gears for the back would be an upgrade. You’ll need the lockers also. Can’t go wrong with vanquish gears either.


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[smc-93]

Originally Posted by DRED805

Correct. I was hoping there'd be some gear reduction in the portals, but they're two 16 tooth gears. Still worth it.

Thought so. IMO, completely defeats the purpose of portals.

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[D-Dub]

Originally Posted by smc-93

No the (with the SSD gears at least) locker comes separately. You'd have to make sure you got 6 bolt gears and the matching 6 bolt locker if you go that route.
https://www.amainhobbies.com/ssd-rc-...aztakqhb2xactz
https://www.amainhobbies.com/ssd-rc-...alt2qayc2xactz
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That clears that up! I saw what they call a locker, but the name makes no sense to me. Its not a locker.

[smc-93]

Originally Posted by D-Dub

That clears that up! I saw what they call a locker, but the name makes no sense to me. Its not a locker.

It's a locker in the sense that it locks the half shafts to the ring gear so everything rotates together as opposed to and open/selectable differential.

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[DRED805]

Originally Posted by smc-93

Thought so. IMO, completely defeats the purpose of portals.

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I guess. Except for that whole ground clearance thing.

[smc-93]

Originally Posted by DRED805

I guess. Except for that whole ground clearance thing.

That's fair.

As Fricker mentioned though, a big benefit to after market gears is the OD/UD options. It makes a big difference, especially with both OD and UD in the front and rear (respectively)

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[DRED805]

Originally Posted by smc-93

As Fricker mentioned though, a big benefit to after market gears is the OD/UD options. It makes a big difference, especially with both OD and UD in the front and rear (respectively)

If that was directed at me, I said in my first post that my vanquish underdrive rear diff fit perfectly.