How to Install RC Servo Saver Correctly
03/08/2026
A servo saver is a small steering part with a big job. It takes the shock out of impacts that would otherwise travel straight into your steering servo, helping to protect the gears when a wheel catches a kerb, rock or rut. Knowing how to install rc servo saver properly matters because a saver fitted one spline out, overtightened or left loose can make a good RC car steer badly.
This is a straightforward job on most RC cars, lorries and crawlers, but the correct order is essential. Centre the electronics first, fit the saver in the correct position, then set the steering travel only after everything is connected.
What an RC servo saver does
A standard servo horn is a solid arm fixed directly to the servo output spline. A servo saver looks similar but uses a spring-loaded or cushioned mechanism. Under a hard knock, it gives slightly rather than forcing the servo gears to absorb the whole impact.
That protection is particularly useful on bashers, monster lorries and vehicles that see rough ground. It can also be sensible on a crawler with heavy wheels, although rock crawlers often need a firmer saver or a solid horn for precise steering control. There is always a trade-off: a softer saver offers more protection, while a firmer one gives a sharper steering feel.
Before ordering a replacement, check that it matches your servo spline count and the vehicle’s steering layout. Common spline counts include 23T, 24T and 25T, but they are not interchangeable. Many standard RTR servos use 25T, while some models and aftermarket units use a different fitting. Also check whether the vehicle needs a specific moulded servo saver, a horn-and-linkage assembly, or a universal adjustable type.
What you need before fitting
Set out the model on a clean bench and make sure the front wheels can hang freely. You will normally need a suitable hex driver or screwdriver, a nut driver or socket for the servo-saver nut where applicable, side cutters if a cable tie needs replacing, and a small amount of medium-strength threadlock for a metal-to-metal fixing screw.
Do not use threadlock on plastic threads. It can damage the plastic and makes future servicing unnecessarily difficult. Keep the small servo retaining screw safe too. It is easy to lose and should not be substituted with a random screw that bottoms out in the servo output shaft.
If the car has been used outdoors, brush away dirt around the steering assembly first. Grit caught in the bellcranks or steering posts can be mistaken for a faulty servo saver after installation.
How to install an RC servo saver step by step
1. Switch on and centre the radio system
Start with the transmitter switched on, steering trim at zero, and steering dual rate set to its normal or maximum setting. Then switch on the receiver and vehicle. Let the servo move to its electronic centre position.
This is the stage people most often skip. If you remove the old horn with the steering off-centre, then fit the new one without centring the servo, the model may drive with the wheels pointing left or right even when the transmitter wheel is straight.
Once centred, switch the vehicle off. For electric models, disconnect the battery. For nitro models, switch off the receiver pack and make sure the engine cannot start during the work.
2. Remove the old horn or saver
Access differs between models. On some RC cars, the servo saver sits on top of the chassis and is easy to reach. On others, especially compact 1/10 models, you may need to remove the receiver box cover, top deck, bumper assembly or steering brace first.
Disconnect the steering link from the old saver if required. A ball-link tool is ideal, but careful leverage with a small flat driver can work. Avoid pulling on the steering link itself, as it is easy to distort a plastic rod end.
Remove the centre screw from the servo output. Lift the horn or saver off the spline. If it is tight, gently rock it from side to side rather than prising hard against the servo case. Check the old part for cracks around the spline, a weak spring, rounded teeth or excessive movement in the pivot.
3. Build the replacement saver if necessary
Some servo savers arrive as a complete assembly, while others need the spring, upper arm, lower arm and retaining hardware assembled before fitting. Follow the orientation of the original part or the vehicle manual. The output arm needs to point in the right direction for the steering linkage to line up without forcing it sideways.
If the saver has an adjustable spring collar, begin with the manufacturer’s recommended setting or match the old assembly. Do not wind it fully tight immediately. A saver that cannot move at all is effectively a solid horn, which removes much of its protection.
4. Fit the servo saver onto the centred servo
With the transmitter trim still centred and the vehicle switched off, place the new servo saver onto the output spline. Aim to position the arm as close as possible to the same neutral angle as the original. On many vehicles this means the arm is at 90 degrees to the chassis centreline, but not all designs are the same.
The splines allow only small adjustments, so get it as close as you can. Fit the centre screw and tighten it firmly but carefully. The screw should hold the saver securely without stripping the servo’s output shaft threads. If it screws into a metal output shaft, a tiny amount of medium threadlock is appropriate. Leave it off if it threads into plastic.
Reconnect the steering link. Ensure the ball end is fully seated and that the linkage is not under tension at neutral. A link angled sharply or forced sideways can cause drag and premature wear.
5. Check the steering geometry before powering up
Turn the wheels by hand from lock to lock. The bellcranks, steering posts, rod ends and saver should move freely. Nothing should catch on the chassis, bumper, suspension arms or electronics.
Look closely at the wheels with the steering centred. If they are visibly pointing to one side, adjust the steering turnbuckles or linkage length where your model allows it. Avoid correcting a large mechanical misalignment with transmitter trim alone. Trim is for small final adjustments, not for hiding an incorrectly fitted saver.
Set endpoints and test the saver
Reconnect the battery and switch on the transmitter, then the vehicle. With the model raised so the wheels are off the ground, turn from full left to full right slowly. Listen for servo buzzing at either end of travel. Buzzing usually means the servo is trying to push the steering past its mechanical stop, which can overheat or damage it.
Use the transmitter’s steering endpoint adjustment, also called travel adjustment, to stop the servo just before the steering reaches a bind. Set each direction separately if your radio allows it. This is especially worthwhile after fitting an aftermarket servo, different steering knuckles or a new saver with a different arm length.
Then place the model on the ground and check the steering again. The wheels should return close to centre after a turn. Hold one front wheel gently and turn the transmitter wheel. The servo saver should give slightly under deliberate resistance, then return cleanly. If it slips too easily during normal steering, tighten its spring adjustment in small increments. If it never gives at all, back the tension off slightly unless your setup specifically requires a solid steering connection.
Common fitting problems and what they mean
If the wheels are off-centre after installation, first confirm the transmitter trim is at zero and that the servo was powered and centred before the saver was fitted. Remove and reposition the saver by one spline if needed, then use the steering link adjustment for the final correction.
A model that steers more one way than the other may have unequal transmitter endpoints, an incorrectly positioned saver, or a steering linkage that is not centred. Check the mechanical setup before assuming the radio is at fault.
If the steering feels vague, inspect the saver spring tension and every ball end in the system. A loose spring, worn ball links, sloppy bellcrank bearings and cracked steering arms can all create the same wandering feel. Tightening the saver will not cure wear elsewhere.
A servo that chatters or gets hot needs attention straight away. Check for binding through the entire suspension travel, not just with the chassis on the bench. Compression can change the angle of steering links on some models, particularly crawlers and vehicles with modified ride height.
Choose protection that suits how you drive
There is no single best servo saver setting for every model. A high-speed basher regularly landing jumps benefits from a saver that can absorb a sharp hit. A race car may need a firmer setting for repeatable turn-in. A crawler with a powerful high-torque servo and heavy tyres needs enough stiffness to hold a line, but still needs steering components that are free and correctly aligned.
After the first run, check the centre screw, steering links and saver tension again. A few minutes spent setting up the servo saver properly can save a stripped gear set, a missed day of running and the cost of a replacement servo.