AR45 on SCX10.2 ???

[318aye]

Howdy!

With the AR45 being used on the Capra and SCX10.3 I figured there would be a few folks swapping their AR44's out for the newer portal style axle but didn't find anything via search.

Anyone done this? Prohibited by link or gearing issues? Any other reason I'm dumb?

TIA for your input! PM if you have a line on a set, also can't figure out how to order the requisite complete axle kit from Axial just yet.

 

[318aye]

Alternatively, if I'm missing something more cost effective (portal axle adapters, something Chinese, etc), lmk! Really just looking for a little more clearance / something fun to get into.

 

[three86]

I was going to put just the back axle from my scx10.3 on my scx10.2 but then I realized the back wheels would spin the wrong way. I think doing just the back would overdrive the back as well. Other than that the back would be a perfect fit for the links and shocks.

Another way to get more clearance is put taller tires on.

 

[Fricker08]

Just a little clarification, the Capra and scx10.3 run different axles. Capra F9 portals and the ar45 on the 10.3. Biggest differences are width, the F9’s are quite a bit wider and the steering setup. F9 is servo on axle ar45 is chassis mounted servo. I believe on both rigs the gearing in the trans is 1:1 and the gear reduction is at the portal. Hopefully some others will chime in


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[318aye]

I was going to put just the back axle from my scx10.3 on my scx10.2 but then I realized the back wheels would spin the wrong way. I think doing just the back would overdrive the back as well. Other than that the back would be a perfect fit for the links and shocks.

Another way to get more clearance is put taller tires on.

Ahh so it sounds like you'd need the entire drivetrain transmission back to make it work from a drive direction standpoint?

I've seen some aftermarket transmission setups overdriving the front wheels and I wouldn't mind trying that out, but an overdriven rear seems like it'd have a negative effect.

 

[318aye]

Just a little clarification, the Capra and scx10.3 run different axles. Capra F9 portals and the ar45 on the 10.3. Biggest differences are width, the F9’s are quite a bit wider and the steering setup. F9 is servo on axle ar45 is chassis mounted servo. I believe on both rigs the gearing in the trans is 1:1 and the gear reduction is at the portal. Hopefully some others will chime in


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Great catch, thank you for the followup! I think the fella above corroborated your "gearing at the portal" question, so it seems like you'd need to either swap the trans or modify the gearing to get the ar45's to work.

Thanks for the help all!

 

[three86]

Ahh so it sounds like you'd need the entire drivetrain transmission back to make it work from a drive direction standpoint?

I've seen some aftermarket transmission setups overdriving the front wheels and I wouldn't mind trying that out, but an overdriven rear seems like it'd have a negative effect.

the portal gears reverse the direction of the wheel spin. So if both are portals it is fine or both are not it is fine. If you want one portal and one not you would need to change the direction of the drive shaft spin somehow with the transmission or a differential gearing. Or maybe flip the axle the non-portal one or you defeat the clearance purpose unless you can also rotate the portal part (on my 10.3 you can't it is one piece).

You wouldn't need the whole transmission just all wheels need to spin the right direction at the same time After having both the scx10.2 and .3 I prefer the non-portal and simple transmission of the 10.2 at least for now with how I have them setup. I like the less weight and lower center of gravity. Although the 10.3 gets closer with smaller tires and a lighter weight body and I am still working with it. It is kinda fun taking turns fast and almost tipping over but then preventing the tip over at the last second possible.

 

[three86]

Great catch, thank you for the followup! I think the fella above corroborated your "gearing at the portal" question, so it seems like you'd need to either swap the trans or modify the gearing to get the ar45's to work.

Thanks for the help all!

The back axle would be a straight swap and fits fine I actually did it before realizing wheels spin the other way. The front I would need an ar45 front axle with the pumpkin in the middle to put it on my 10.2 kit.

10.2 kit front axle:

10.3 kit front axle:

 

[318aye]

Thanks for the thorough photo explanation! Guess I'll punt on this for now.

 

[Topher Builds]

Well for a 10.2 the pumpkin doesn’t need to be in the middle. You can tell by looking at the pic posted (10.2 is the top one) that there is plenty of room for that drive shaft to move to either side.

Now putting a 10.2 axle on the 10.3 chassis would be a different story because of the skid for the forward motor mount would get in the way for a center pumpkin. On these you need an offset pumpkin to work.

The main issues you’ll run into are with links, the mounting positions on the AR44 vs AR45 are different enough to cause issues that would prevent stock 10.2 links from working. One big one being the location of the upper link mount on the axle, your 10.2 link will likely be too long. The panhard and lower links may be a bit different too. Might have the best chances using the 10.3 links on the 10.2 chassis and seeing how close that gets it. May need to tweak the panhard still though.

For gearing you could run a slightly smaller spur and that will help make up the difference from the portal reduction.

With all that being said, I’m not sure I’d throw a set of portals on a 10.2 since there isn’t a ton of clearance on the rails. It could ride a little high. Vs410 chassis swap may not be a bad idea to consider.

Great comparison below...

 

[three86]

Topher I think you might be right. I was thinking that the driveshaft would hit the one upper link that the 10.2 has but if you used the 10.3 link configuration it might work with a longer driveshaft. The pumpkin on the side might graze the servo at full shock compression on one side but maybe not it would be close. If so you could move the servo to the front. The lower links are the same size on both and I think the upper link from 10.3 would work in the same hole on the other side of the 10.2.

 

[85Bronco]

I bought an10.3 kit just to do this swap. I've got a umg10 and the lack of portals really bugs me on a unimog. If I'm reading this right, using the 10.3 links should make this work? Should I swap the pinion to adjust the gearing or would it be worth using the 10.3 transmission? It has a Holmes 13t crawlmaster in it and is really faster than it needs to be anyway, I wouldn't mind a lower crawl ratio.

 

[Fricker08]

This deal has peaked my interest, has anyone had any luck? I’ve got a Umg 6x6 in the mail and wouldn’t mind putting it on portals but I may just look at doing an ssd swap or something


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[mikro383]

I'll chime in with another question, I know capra axles are wider but is the 10.3 any wider then the 10.2 hex to hex? What about the new straight axle 10.3? Are they all the same width? If the 10.3 is just a touch wider might also be another advantage

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