How to Change a Kart Axle: Step-by-Step Guide
Changing the axle is one of the most frequent jobs in karting, and it does not only happen in the workshop. Those who work seriously on setup do it right at the track, between one session and the next, to adapt the kart to the conditions of the moment. You change it when the axle breaks after an impact, but much more often you change it to go from soft to hard, or vice versa, depending on how the kart responds.
It is not a difficult job. It is a long one: allow about 40 minutes the first time, less once you get the hang of it. Here you will find everything you need to do it properly, without damaging anything.
In short To change the axle you remove the chain guard, wheels, hubs, sprocket carrier and disc carrier, loosen the bearing grub screws and slide the tube out with the extractor, never hitting the edge directly. The first time it takes about 40 minutes.
When an axle is changed
There are two main situations.
Breakage: after a violent contact the axle can bend or snap. In this case no repairs are possible: it is replaced.
Setup: those who work seriously on setup change the axle several times over the same weekend. Soft in the morning on a cold track, hard in the afternoon when the track is rubbered in. Or it is changed to alter the interaction with the chassis.
In both cases the procedure is identical. The only thing that changes is how often.
The tools you need
Before starting, lay everything out on the bench. Stopping halfway through to look for a spanner is no fun.
10 mm spanner (for the chain guard)
8, 6, 5 and 4 mm spanners
4 mm Allen key (for the grub screws)
Rubber or plastic mallet
Axle extractor (with Teflon base)
Tape measure
Fine sandpaper
Pliers (for the exhaust springs, if you remove it)
The axle extractor is not compulsory, but it is strongly recommended. Without it you tend to hit the axle directly with the hammer, damaging the edge. With the extractor you strike the Teflon base and the axle comes out intact, ready to be refitted without problems. It costs around 25-30 euros and pays for itself the first time you do not have to straighten a damaged edge.
Disassembly: what to remove first
The axle does not come out on its own. Everything is around it: sprocket carrier, brake disc carrier, hubs, bearings. All the accessories must be removed before you can slide it out.
1. Chain guard The first item to remove. It depends on the kart model: some need a 10 mm spanner, others have a manual release. Put it aside somewhere it will not get in your way.
2. Rear wheels Remove both wheels. Reach the nuts with the appropriate spanner and make room to work freely.
3. Exhaust (optional) It is not essential to remove it, but working with the exhaust out of the way is more comfortable. If you decide to take it off, use the pliers to remove the springs: those on the engine mount and those on the bracket. Careful: springs under tension can snap back. Move them calmly.
4. Hubs and grub screws The hubs are locked onto the axle by grub screws, small Allen screws that press directly on the tube. With the 4 mm Allen key, loosen them on both sides without removing them completely. Then slide off the hubs.
5. Sprocket carrier and disc carrier Same procedure: loosen the grub screws, then slide off the components. If the disc carrier is integrated with the caliper, first loosen the caliper from the chassis to have more freedom of movement.
6. Bearings: loosen the grub screws The bearing housings also have grub screws that lock the axle in position. Loosen them all (there are usually two per bearing housing) with the 4 mm Allen key. You do not need to remove the bearings from the chassis; the axle just has to be free to slide inside them.
At this point the axle is held only by friction with the bearings. You are ready to slide it out.
How to slide out the axle without damaging it
This is the step where most mistakes are made.
The instinct is to take the hammer and hit the edge of the axle directly to push it out. Do not do it. Every direct blow on the metal deforms the edge, which then makes it difficult, sometimes impossible, to refit the axle precisely in the bearings.
The correct method: use the axle extractor. It hooks onto the edge of the tube and has a Teflon or aluminium base that absorbs the hammer blows. This way you can push hard without damaging anything. With a few firm blows the tube slides out of the bearings.
If you do not have the extractor, at least use a piece of wood or plastic as protection between the hammer and the axle. It is not the ideal solution, but it is better than hitting the metal directly.
Once free, pull the axle out sideways, usually from the left side, but it depends on your kart’s configuration. Check that no components have stayed stuck along the way.
Preparing the new axle
Before inserting the new axle, clean the tube with fine sandpaper. The aim is not to polish it, but to remove any oxidation or surface burrs that could hinder sliding in the bearings.
Run the sandpaper along the whole length with light circular movements. If the axle is brand new, this step is usually not needed; just wipe off any protective oil film with a clean cloth.
Refitting: how to reinsert the axle
The axle is inserted into the chassis from one side, sliding it through the bearings. The components are slipped onto the free end as the tube advances, not before insertion, because they would not pass through the bearings.
Sprocket carrier: slip it onto the free end of the axle after the tube has passed through the first bearing, before it reaches the second. This way it is already in the central position once the axle is fully inserted. Disc carrier: it is slipped on from the outer end after the axle has passed through both bearings.
Centring the axle: how it is done
The axle is centred when it protrudes by the same length from the bearing housings on both sides. If the protrusion is different, the kart behaves asymmetrically and what you feel in corners cannot be managed with normal adjustments alone.
How to measure: use a tape measure. Measure the distance between the bearing housing and the end of the axle on the right, then do the same on the left. The two values must match.
How to correct: if the axle is not centred, loosen the bearing housing grub screws with the Allen key, then use the rubber mallet to give light taps on the end that protrudes more, pushing the tube towards the centre. Recheck the measurement. Repeat until both sides are balanced.
When the axle is centred, tighten the bearing housing grub screws evenly and in a controlled way, not fully all at once but progressively, so as not to shift the tube again while tightening.
Refitting wheels and accessories
The axle is inserted into the chassis from one side, sliding it through the bearings. The components are slipped onto the free end as the tube advances, not before insertion, because they would not pass through the bearings.
Sprocket carrier: slip it onto the free end of the axle after the tube has passed through the first bearing, before it reaches the second. This way it is already in the central position once the axle is fully inserted. Disc carrier: it is slipped on from the outer end after the axle has passed through both bearings.
Only at this point fit what goes on the ends:
Hubs: slide them to the correct position for the track width you want to use, then tighten the grub screws.
Chain: put it back under tension, tight enough not to jump off, loose enough not to stress the engine bearing.
Chain guard: refit it.
Wheels: refit them and check the tightening.
What to check before going back on track
Three final checks that must never be skipped.
Chain alignment: look along the chain from behind. Pinion and sprocket must be perfectly in line. If they are offset, the chain wears quickly and can jump off.
Brake disc play: with your hands, push the disc slightly to the right and to the left. It must not move noticeably. If it moves, recheck the tightening of the disc carrier.
Axle centring: recheck the measurements one last time, cold, before going out. It seems redundant, but tightening the grub screws sometimes shifts the position slightly. One minute now is worth more than ten laps to interpret on track.
Frequently asked questions
What tools do you need to change a kart axle?
The main ones: a 10 mm spanner for the chain guard, 4-8 mm spanners, a 4 mm Allen key for the grub screws, a rubber mallet, an axle extractor with Teflon base, a tape measure and fine sandpaper. The extractor is not compulsory but avoids damaging the axle edge, an investment of 25-30 euros that pays for itself straight away.
How do you slide out the axle without damaging it?
With the axle extractor: it hooks onto the edge of the tube and has a Teflon base that absorbs the hammer blows. You must never hit the metal directly with the hammer: every blow deforms the edge, making refitting difficult. TKS RaceLab always uses the extractor for every axle change.
How do you centre the kart axle after fitting?
Measure with a tape measure the distance between the bearing housing and the end of the axle on the right and on the left. The two values must be identical. If they are not, loosen the bearing housing grub screws and correct the position with the rubber mallet, then recheck the measurements before tightening for good. TKS RaceLab checks axle centring on every kart before every session.
How long does it take to change a kart axle?
About 40 minutes the first time, progressively less with experience. The procedure is not difficult, but it is long: you have to remove the chain guard, wheels, hubs, sprocket carrier and disc carrier before you can slide out the tube. Those who race competitively learn to do it quickly between sessions. With TKS RaceLab’s Arrive & Drive service the axle change is handled by the technical team.
Want to try it on track with us? With our Arrive & Drive you get the kart, the track and the technical support of the TKS RaceLab team, at Lonato, Franciacorta, Cremona and Ala.Discover Arrive & Drive →
👉 You will find axles and bearings for the change in our shop: the Maranello axles and the Maranello 50-80 axle bearing.
Conclusion
Changing the axle is a job every karter should know how to do. It does not require advanced skills, it requires method and a little patience. Done well, it lets you work on setup precisely and really understand what you are changing on the kart.
Questions about this topic?
Message us on WhatsApp: we answer personally, with the experience of people who live at the track. And if you want to drive a real racing kart, with Arrive & Drive you get into one of ours, ready on track. The right spare part? You will find it in the shop.
Arrive & Drive Pro by TKS RaceLab: 2026 karts with Rotax Senior MAX and DD2 engines, Alfano 7 telemetry and trackside technical support at Lonato, Franciacorta, Cremona and Ala. Message us on WhatsApp for information and availability.
TKS RaceLab | Performance Engineering Karting | tksracelab.com
Read also: Kart axles: soft, medium and hard, what really changes on track → · Magnesium or aluminium wheels: what really changes on a kart → · How to choose the right kart axle: track, conditions and behaviour → · Kart axles: the complete guide →
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Author: Sergio, TKS RaceLab | Published: 10 June 2026 | Updated: 4 October 2026
TKS RaceLab is the Italian online store dedicated to karting: spare parts, accessories and everything you need to get on track. With Arrive & Drive you arrive at South Garda Karting (Lonato), Franciacorta, Cremona or Ala and find your kart ready to go. No hassle, just driving.
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