My new Mavic 3 classic's rear arm isn't as springy as the other. If holding upright level to the ground you can place the arm close to fully open but it won't spring into place.  Even having it a quarter of the way from lock open position and it won't spring into place. It seems to be to tight against the chassis. The other arm will just spring into pace regardless. It's hasn't affected it in flight, and I assume it shouldn't cause any issues considering that the arm is forced into lock position from just the drones down draft. I could send it in for warranty but the thing is, it's a good reliable drone, and I know that DJI can swap for a refurbished drone instead of fixing mine. Not sure how to proceed, any opinions?

Sounds like it might be a manufacturing defect on that one arm.  As it could lead to troubles sooner or later I'd be inclined to send it in for warranty replacement.  As the Mavic 3 Classic is relatively new there probably aren't many refurbs available yet so you could well get a new replacement.  

Looking at this video

around 9:06 the Mavic 3 uses a similar design of pivot to those used in the mini 1 & 2 and the wiring for the motors etc. run through the centre of the pivot.
So, to replace the actual pivot would mean the wires have to be disconnected inside the drone and that would mean opening the drone which would invalidate warranty.
To be honest it looks like the Mavic 3 might be a bit of a nightmare to dismantle and reassemble.
I too would suggest sending the drone in as a warranty claim.

Just a point, if by "won't spring into place" you just happen to mean ( I doubt you do but this is a "just in case") that you release ANY arm once it is past the 'tipping point' and let the spring 'drive' the  arm into either the open or closed position, I would suggest that that is a bad thing to do, it may over stress areas of the airframe around the pivots.

Sean-bumble-bee Posted at 12-4 05:35
Looking at this video
https://www.youtube.com/watch?v=VwU77g2Lcgo
around 9:06 the Mavic 3 uses a similar design of pivot to those used in the mini 1 & 2 and the wiring for the motors etc. run through the centre of the pivot.

I understand what you mean about letting it spring back into place, I wasn’t doing that to start with. I noticed the problem when I was unfolding the arms, that the problem arm wasn’t as smooth as the other one, so I looked into it further.

One thing to consider though, is that while in flight, the down draft of these drones keeps those pivot points locked into place so I don’t think this issue will cause a problem in flight. That’s my main concern.

Sime Posted at 12-4 11:28
One thing to consider though, is that while in flight, the down draft of these drones keeps those pivot points locked into place so I don’t think this issue will cause a problem in flight. That’s my main concern.

True, the thrust from the propeller should keep it in position but the lack of spring indicates a problem in the pivot. It might be a spring that could have taken a set or it broken spring or it could be something progressive that could lead to the failure of the pivot and detach the arm, do you want to risk your drone on that?

Besides 1) I had something somewhat similar in a crash damaged M2Z, the 'slack' allowed the arm to droop at low power settings and on increased power smack into the underside of the airframe 'stop'. I think the drone also wobbled in certain situations but the drone was only flown for a minute or so in a proving/test flight, it was then dismantled and the damaged component found and replaced.

Besides 2) You have posted a thread stating there is a problem and people have advised you to send the drone in for a warranty repair.
If you do not send the drone in but instead continue to fly it and it subsequently fails and the drone crashes and is damaged, DJI might be able to argue that the failure is due to your actions and not covered under warranty or care refresh etc.
Is it worth the risk? In my opinion, on a new, just released drone, no it is not......but it is not my drone or money, at risk.

Just to confirm, the spring in the pivot works, but what I think is happening is that the way that arm is installed, is seems to be closer to the body of the drone compared to the other, causing friction between the arm and the chassis, which in turn makes that pivot stiffer.
In the first post, I said that if you hold the drone upright and level, gravity is enough to stop the arm popping into place, but as soon as you start to turn the drone over, it pops into place. Also there is a sound difference between the two pivots.
Basically it’s more of an issue of contact between the arm and chassis over and actual defect in the pivot itself.

I’ve also sent in a repair request to DJI asking for their opinion also.

I’ve also concluded after thoroughly inspecting it, that the problem is that the arm is closer to the chassis than the opposite one, kinda like it’s been tightened more making it more restricted.

Thank you for reaching out and we're deeply sorry for the trouble that this has caused. In this kind of situation, I'm afraid that you may consider sending the unit in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support . Also, the warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. Thank you for your kind and understanding.

Sime Posted at 12-4 20:20
I’ve also concluded after thoroughly inspecting it, that the problem is that the arm is closer to the chassis than the opposite one, kinda like it’s been tightened more making it more restricted.

Ok, I will keep this short and to the point.
You say there is a physical problem with a virtually brand new, just released drone.
If the rear pivot is broken and or misaligned or something else is causing the problem then it needs to be fixed.
Any attempts by you to rectify the problem are likely to invalidate care refresh and or warranty.
My advice is send the drone to DJI as a warranty claim.

Lol, at what point in time did I say I was going to fix it myself.

Chill bro.

You didn't, it was a preventative suggestion just in case you were thinking of it.