Scrap Mechanic Bearings and Tank Steering Explained

There is only one bearing, and that is the point

Search the item list and you will find exactly one Bearing. No Bearing Level 1 through 5, no sport version, no heavy duty version. Everything that looks like a bearing upgrade is actually an upgrade to the thing driving it.

The Bearing itself is close to free: 1 Metal Block Level 1 at the Craftbot, or 3 Scrap Metal Blocks at a workbench or portable crafter, five seconds either way. It stacks to 20. Of its four ratings, durability is 1, the lowest in the game, so a bearing is the part a crash usually breaks first.

Anything you place on a bearing revolves with it. On its own a bearing is a free spinning hinge. Connect it to something, and the bearing stops being a hinge and starts being a motor, taking a target speed and a force from whatever is on the other end of the connection.

What the driver decides

Three kinds of part drive bearings, and each gives them a different character.

A Gas Engine always asks its bearings for the same target speed, 4244.132 degrees per second, and uses the gear to set how much force it puts behind that request. This is why a gas car in first gear still reaches the same top speed on the flat as it does in top gear, and why it stalls on a hill instead.

An Electric Engine does the opposite. It always pushes with a torque of 1000 and uses the gear to set the speed it wants. Selecting a gear on an electric drivetrain selects an actual rpm, which is why lifts, cranes and turntables are almost always electric.

A seat drives bearings for steering rather than propulsion. Connect a bearing to a Driver’s Seat and it turns left and right with your input instead of spinning. Whether a bearing steers or drives is decided by which of the two you connected it to, not by anything on the bearing.

Connection limits

Every driver has a cap on how many bearings it will accept, and it goes up with the level.

Level	Engine	Seat	Saddle	Driver’s Seat and Saddle
1	2	2	3	6
2	4	4	4	8
3	6	6	6	12
4	8	8	8	16
5	10	10	10	20

The scrap tiers sit below all of it: a Scrap Gas Engine drives 2 bearings, a Scrap Seat takes 2 connections and a Scrap Driver’s Seat takes 4.

The engine limit is the one that bites first. A four wheel drive car needs at least a level 2 engine, and eight wheel drive needs level 4. Splitting the drive between two level 1 engines works and is often cheaper than one upgrade, at the cost of two fuel containers to keep topped up.

Tank steering, and why it needs an electric engine

Tank steering means turning by driving the two sides of the vehicle at different speeds, with no steered wheels at all. Scrap Mechanic has this built in, through a bearing setting rather than through logic.

Point the Connect Tool at a bearing that is connected to an Electric Engine and press E. You get three choices: Standard, Differential Left and Differential Right. Standard is what every bearing does by default. Assign the bearings on the left of the vehicle to Differential Left and the ones on the right to Differential Right, and the engine starts steering them independently.

From then on:

• Driving straight, both sides run at the speed the gear asks for.
• Turning while on the throttle, the outer side keeps full speed and the inner side drops to 33% of it. Hold sprint at the same time and the inner side runs at 67% instead, which widens the turn.
• Turning with no throttle at all, the two sides run in opposite directions, so the vehicle spins on the spot.

That last behaviour is the one worth building for. A tracked or six wheeled machine that can pivot in place is far easier to drive around a warehouse than anything with a steering axle.

Two catches, and neither gets mentioned much.

The first is that bearing modes belong to the Electric Engine. A Gas Engine drives every bearing connected to it identically and has no bearing mode menu at all. If you want differential steering without electricity, you are back to building it yourself out of two engines and two sets of controls.

The second is that the modes only do anything while a seat with steering is driving the engine. The engine reads the steering input to work out which side is the inner one, so with no steering seat in the chain it falls back to driving every joint the same way and your assigned modes sit there doing nothing. If a tank build refuses to turn, check the seat before you check the modes.

One bonus: an Electric Engine will drive a suspension spring as well as a bearing, and a spring it drives can be given a differential side like any other joint. A Gas Engine only ever collects bearings.

Steering settings on the seat

Seats have a separate unlock that is easy to confuse with bearing modes, and it is worth keeping them apart. A Driver’s Seat or Driver’s Saddle at level 5 lets you press E on connected bearings with the Connect Tool to open its steering settings, which is where you adjust how far and how fast a steered bearing turns.

That panel is not the engine’s. The seat’s settings shape a bearing the seat steers; the engine’s modes assign a bearing the engine drives to a side of the differential. Different menus, different jobs, and an engine cannot replace a level 5 seat because it does not steer anything.

A Turret Seat gets there sooner and in stages. Level 3 unlocks bearing power, level 4 adds the bearing settings, and level 5 also seals the cabin for oxygen.

Suggested layouts

None of these are enforced by the game. They are the arrangements that hold up.

Two wheel drive with a steered front axle

Rear wheels on bearings connected to the engine. Front wheels each on a bearing connected to the Driver’s Seat, which steers them. Nothing else.

It is two engine connections and two seat connections, so a level 1 engine and a level 1 seat cover it, and it is the layout to build before you have any Component Kits to spare.

Four wheel drive, four wheel steer

All four wheels on bearings connected to the engine, and each of those bearings mounted on a second bearing connected to the seat. The seat turns the mount, the engine spins the wheel.

It needs a level 2 engine for the four driven bearings and a level 1 Driver’s Seat for the four steering bearings. Steering all four makes the machine turn in a much tighter circle, which takes getting used to.

Six wheel tank

Three bearings a side, all on one Electric Engine, all six set to Differential Left or Differential Right. No steering bearings at all, but the seat still has to be a steering one and still has to drive the engine, because that is where the engine reads which way you are turning.

You need a level 3 electric engine for six driven bearings. Wheels with more grip make the pivot cleaner, because a tank turn works by making the inside wheels scrub.

Bearing and steering questions

Are there different levels of bearing?

No. The game ships one Bearing and it has no upgrade path. The suspension parts that come with a bearing built in use that same bearing; they save you a part rather than giving you a better one.

Why won’t my bearing spin?

Almost always because nothing is driving it. A bearing with no connection is a free hinge and only moves when something pushes it. Connect it to an engine to make it a motor, or to a seat to make it steer, and check that the engine has not already used up its bearing limit.

How do I make a tank that turns on the spot?

Use an Electric Engine, connect every driven bearing to it, then set the left side bearings to Differential Left and the right side to Differential Right with the Connect Tool. Drive it from a seat with steering, because the engine only applies the modes while a steering seat is controlling it. With no throttle input, turning then runs the two sides in opposite directions and the vehicle pivots.

Can I do differential steering with a gas engine?

Not through the bearing mode menu, because that menu belongs to the Electric Engine. The workaround is two engines, one per side, each with its own control, which costs you two fuel supplies and a lot more parts.

How many bearings can one engine drive?

Two per level, so 2, 4, 6, 8 and 10 from level 1 to level 5. The Scrap Gas Engine drives 2. The count is of bearings rather than wheels, so a bearing that only carries a suspension arm uses one of your slots too.

What is the fastest a bearing will spin?

Under a Gas Engine the target is 4244.132 degrees per second in every gear, so that is the ceiling for a gas drivetrain. An Electric Engine sets the target from the gear instead, and its top gear at level 5 asks for 6990 degrees per second, though it only has a torque of 1000 to get there with.