The short version
- The inner joint is held in the transmission by a circlip that must audibly click home.
- Fit a new circlip, and fit it with the opening away from the direction of load.
- Clean and lightly anti-seize the outer splines, or you will fight the same axle next time.
- Tug the inner joint outward by hand before you go any further. If it moves, it is not seated.
Getting the axle out is the hard part. Refitting the CV axle is the part that gets rushed, and it has one failure mode that is genuinely dangerous.
An inner joint that is not fully clipped in can walk out of the transmission on the road.
The circlip is the whole job
The inner stub carries a circlip in a groove. It compresses as the shaft enters the differential and springs into a matching groove inside.
There is no bolt and no retainer on most designs. That clip is the entire retention.
Fit a new one. They are pennies, and a tired clip does not spring out with enough force to seat properly.
Making it seat
| Step | Why |
|---|---|
| New circlip, opening positioned | An old clip may not spring fully |
| Line the splines up first | Cocked splines will not let it in |
| One firm push or tap | Steady pressure lets the clip drag |
| Listen and feel for the click | That is the clip entering its groove |
| Pull outward by hand | The only real confirmation |
Tightening the hub end to draw the inner joint in stretches the axle. It loads the bearing at the same time.
The inner end must be seated before the outer end is clamped, not because of it.
Refitting the CV axle at the outer end
Wire brush the axle splines and the inside of the hub until the profile is clean metal.
A thin film of anti-seize on the splines is what prevents the corrosion that welds them together over the next decade.
Keep it off the threads, because a lubricated thread changes what a torque figure delivers.
Why that matters is on the anti-seize page. The seizure it prevents is on the stuck axle page.
The order for refitting the CV axle
Seat the inner joint and confirm it. Then guide the outer splines through the hub, then start the axle nut by hand.
Do it the other way round and the outer end is captive while you are still seating the inner clip.
The nut itself is single use on most cars, and that is on the staked nut page.
Checking it before the wheel goes on
- Pull the inner joint outward firmly by hand. It should not move at all.
- Check the boot clamps are tight and the boot is not twisted.
- Turn the hub and feel for any binding through the joint.
- Torque the axle nut to specification before the car is lowered.
- Look for weeping at the transmission seal after the first drive.
Why the car must not be lowered with that nut loose is on the supporting page. The torque figure is on the torque specs page.
Common questions
How do I know the axle is seated?
You feel and hear the circlip click. Pulling the inner joint outward by hand then produces no movement.
Do I need a new circlip?
Yes. They cost almost nothing and a tired clip may not spring fully into its groove.
Can I pull it in with the axle nut?
No. That stretches the axle and loads the bearing, and the inner clip still may not be seated.
What happens if it is not clipped in?
The inner joint can pull out of the transmission on the road, which loses drive and dumps gear oil.
Does refitting the CV axle need anti-seize on the splines?
A thin film on clean splines, yes. It is what stops the same axle seizing in the hub next time.
Why is the transmission leaking after the job?
Usually the output seal was nicked while the axle was going in. It has to come out again to replace it.
Does the boot need repositioning?
Check it is not twisted or stretched. A boot installed under tension splits early and takes the joint with it.