I've been awfully quiet, not even lurking, just in one of those not-many-car-problems periods, which is fine with me.  But now I'm back with a question.

Daughter and I set out to change a couple of ball joints on her '03 Forester today.  They were, of course, a PITA to get out, and at this point one is changed.  But we ran into a bit of nastiness in the process:  The inner CV pulled apart, which was a really rude surprise.  I'm accustomed to the older cylindrical type that are roll-pinned to the diff shaft.  This one just presses in and the housing is hexagonal.  But the shaft and tri-pot roller assembly just pulled out of the housing.  Haynes says there's supposed to be a retaining ring in there, but there's no groove for one.  So do you just have to be careful never to tension one of these type, because all that's keeping it together is the boot, and if it slides off, you're SOL?

 

 

It should have a groove with a C clip in there. 

And very odd that it doesn’t have one. If there’s no groove that’s even more odd. 

Can you see a groove internally in the diff? There should be one in there. 

Cheers 

Bennie

Not looking into the diff; it's just sitting on a jackstand (because we had no intention of messing with that) and hard to see in there.  But the CV came out of it with a "reasonable" amount of prying, so my inference is that it's fine.

I just don't know how to proceed with putting this joint back together.  Obviously, Haynes can't be trusted absolutely, but prior experience with the older-style CV - and common sense - say that there should be a retaining ring... and a groove to hold it.  So I'm kind of stuck.

 

So you don’t have the shaft all the way out, it’s just popped out to be loose? 

If that’s the case, it’ll have a c clip in there. Shove it back in and it’ll re-engage, it should hold enough that it doesn’t just slip out easily. 

Cheers 

Bennie

Yep, just pop it back in.  It can take a good wack from the end of the axle.  If you have the lower ball joint out so it's free, you can use the weight of the brake/hub to give you some weight.

You've all misunderstood the question.  The clip at the end of the shaft that gets stuffed into the diff is not the issue.  The clip is there and there's nothing to ask about.

The question was about the clip that isn't inside the inner CV joint itself to prevent it from coming apart.  I just looked at another couple of that type of shaft at a buddy's house, and there's nothing on them either.  So I'm just calling it a $h!++y CV design that relies on the boot to keep it together without any positive retention mechanism for the greezy rollers contained within. 

Edited August 1, 2025Aug 1 by jonathan909

Yes than that would be poor design.  I've never seen one without the retaining circle clip about an 1/8" inside the CV joint.

Subaru or aftermarket?  I always stay with the Green Subaru halfshafts.

Ahhh, now I know what you mean. 

I’ve not seen one without the C clip inside the inner cup that retains the tri-thingy setup or the ball and cage setup - they always have one! 

Even without one, if the vehicle doesn’t come apart while driving or doesn’t hit anything (which would probably render the car useless anyway), then the inner CV “innards” should stay exactly where they are simply by design with how the driveshaft is held between the gearbox and the hub. 

Cheers 

Bennie

Yup, right up until you go to change a ball joint, and the bottom of the steering knuckle swings out a bit, and instead of the rollers in the inner CV hitting that internal stop, the boot pulls off and the rollers fall on the floor.

 

Yeah, right up to that point. At least it’s not life threatening and you know know to expect it now. 

Cheers 

Bennie