ball diff vs gear diff

Ball Diff Vs Gear Diff: What’s The Difference?


Differentials are essential for a vehicle’s handling. Despite the fact that almost every car has one, they are frequently misinterpreted.

The ultimate debate is, which one to pick from ball diff vs gear diff?

A ball diff won’t face an extreme surge in resistance compared to a gear diff. Gear diffs are used on either smoother or high grip surfaces and can last for a long time. On the other hand, a ball diff will deteriorate pretty fast. Gear diffs require some play to function, which is not required for ball diff. Ball differentials provide better smoothness compared to using Gear Differentials.

This is just the gist of the entire article. If you want to make the ideal decision, you need to know the complete section of differences.

So what are you wasting your time for? Get started right away.

What Is A Ball Differential?

A ball differential is a very popular type of differential preferred in RC cars. It uses several small ball bearings that rotates between two plates.

Unlike Gear differentials, ball diffs have balls instead of spider gears. Similarly, flat rings are used in ball differentials instead of output gears.

Ball differentials have no gear teeth and have a smooth outline. It’s also a lightweight option as well!

But, how does a ball differential work?

The steel balls of a ball diff roll on the smooth ring surface. As a result, you get a differential action without any backlash or play. It helps to transmit power from the engine to the driving wheels.


Now that, we’ve cleared up what ball differential is, let’s see how well it fares up against gear differential.

Ball Diff Vs Gear Diff: Quick Comparison

Before we get to the detailed discussion, let’s look at the distinctions in a nutshell. This will help you to make your decision if you don’t have enough time.

It’s just as easy as deciding between inrunner and outrunner.

Here’s a basic comparison between the two differentials:

CriteriaBall DifferentialGear Differential
StructureNo backlash or play requiredRequires some play to function
SmoothnessVery smoothSmoothness lost
Durability and MaintenanceCan detonate fastCan run for a very long time
AdjustabilityModified with little or no disassemblyDoes not have a large adjustment range
WeightHeaviest rotating componentMinimal weight

Just by this, you are able to help yourself. But it’s always better to know more before you make a decision. So let’s look at the detailed head-to-head comparison. 

Ball Diff Vs Gear Diff: Detailed Comparison

The method by which the differential’s output gears interact with the spider gears is the key distinction. The gears of a gear differential are exactly that. 

In a ball differential, the spider gears are substituted by balls. And the output gears are replaced by flat rings. Each design has benefits and drawbacks. So let’s have a look.

Gear and ball diffs both fall under the heading of “open differential.” This means that the diff will willingly send power to the wheel with the most limited traction. In other words, to the wheel that needs the least torque.


The ball diffuses steel balls rolling on smooth rings. This offers different motions without any backlash or play. 

A gear differential, on the other hand, requires considerable play in order to function correctly.

We don’t have a winner here. It’s just how both of the differentials work mechanically. This can vary based on a very personal preference.


In this case, a ball diff has the upper hand. There is no backlash or free play since there are no gears and hence no gear teeth. This allows the diff to seamlessly distribute power to the wheels. 

Especially when making very tight bends. When the velocity differential between the right and left wheels is the highest. In slick situations, its smoothness helps retain traction.

Durability and Maintenance

Durability is an important factor to pick between sbec and ubec. So, let’s see this differentiating factor in the case of ball and gear diff.

This is when a gear differential comes into play. A gear diff may be managed with little or no maintenance once it’s put collectively until it crumbles out. Which can be lengthy at times.

A ball differential, on the other hand, has to be disassembled and rebuilt on a regular basis in order to operate properly. Or not at all, if you’ve left it too long. 

Gear differentials can also take greater power than ball differentials, which is why ball differentials are no longer used in 1/10-scale nitro applications and anything up to 1/8 -scales.



This one is somewhat of a tie. A ball differential may be modified with little or no disassembly. At most, a camber link must be removed. And a driveshaft must be swung out of the way. 

A ball diff, on the other hand, does not have a wide calibration range. It will slip if it is adjusted too slack, resulting in a diff-gear meltdown. Tightening the diff will slow it down significantly. But it will still spin pretty freely even if the screw is locked down.

Gear diffs are supposed to be more adjustable, till it is airtight and can be filled with silicone fluid. You may configure the differential to spin freely or practically locked. Do this by loading it with lighter (higher thickness) or heavier (lower thickness) fluid. To change the fluid, you must remove the diff from the vehicle and access the diff case.

It’s best to check out some recommendations for diff oil before you head on with it.


On the scale, ball differences win. Because they are the heaviest rotating component in most automobiles. Aside from the wheels, having a lightweight diff is critical. But don’t worry, there will be no problem with your RC car moving.

Ball differentials are popular for racing because of their minimal weight and smoothness, especially in applications where power is low enough that a gear diff is not necessary.

Final Verdict

We have placed every fact right in front of you. Hopefully, you’ll be able to pick the one that fits your preferences.

To further help you with it, we have put up pros and cons table stating the advantages and disadvantages of ball diff and gear diff:

Differential TypeProsCons
Ball DifferentialsHas no backlash or free playDeteriorates pretty fast
Smooth power transfer from the engine to the wheelsCan’t handle high power transmission
Helps with traction on slippery conditions.Requires high maintenance
Gear DifferentialsCapable of handling high power transmissionBeing heavy negatively impacts vehicle speed
Durable and long-lastingNot ideal for slippery tracks
Low Maintenance RequiredRequires play and backlash to function

Ball differentials provide better smoothness compared to using Gear Differentials. However, Gear differentials are a more durable option in contrast. Both the ball and gear differentials are versatile when it comes to adjustability.

You should keep in mind that ball diffs are vulnerable to slipping off. So you should look after proper ball diff adjustment before heading on with it.

So go ahead and make your decision. Whatever decision you make, the facts that we’ve mentioned will always support your decision. 


What role does diff oil have in an RC car?

Answer: The acceleration potential of a heavier differential oil is increased. But the off-power steering capacity is reduced. A lighter oil will give you greater on/off power steering, but it will reduce your acceleration.

What does it mean to DIFF out?

Answer: It usually implies that one wheel unloads and transfers power from one tire. It does this with traction to another with no traction. It will almost completely lose driving traction and unload one wheel with very little traction.

What is the recommended weight of differential oil?

Answer: The performance of your automobile is greatly influenced by the diff oils. We propose a basic setup of 5000 CST in the front. 5000 CST in the middle, and 3000 CST in the back.


There you go! We hope that now you can easily come out from the ball diff vs gear diff confusion. If you have any queries, we’re always there to help you. 

We wish you all the best. Take care.

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