Broken CV - How to tell which side ?

My axle was clicking and let go today preventing the car from driving under its own power. (Feels like neutral in whatever gear with bad clicking sounds) Drivers side has a split boot on one of the accordian folds. Passenger side looks good. 99.5 jetta TDI manual. However, grabbing all 4 CV joints by hand I can't tell which one is the one that has let go. Any simple test to know which axle to pull ? Thanks.

Jack up each front wheel individually, put the car in gear then try and turn the wheel that's off the ground. Gears should stop it if the axle is good.

No noise you can follow when it's not moving?

If the driver's side split boot is totally split (not a partial crack) that >might< be it, the splines in the shaft could have striped.
I would think there would be metal shavings inside it.
Maybe even the splines going through the wheel bearing.

I don't think the 'gears' mentioned above would stop the wheel. It would turn through the spider gears.
You would be able to see the inner joint turn if that side was OK unless the flange going into the trans stripped the splines on that side.

Repeat for the other side.

If you are brave maybe you could have someone sit in the car holding the brakes and start it, put it in gear and let the clutch out.
You look under it to see what's spinning and where it stops.
You did indicate the car does not move at all.

Check with the car running in gear (reverse) while you look under from the front. Have a helper or insurance.

Post #2 is correct. Wheel can't turn through the spiders if the trans is in gear and only one wheel off the ground. If it does it isn't in gear or sumpins broke.

Would agree, however, if one sides broke then it won't stop it from turning.
Still like it's off the ground.
I recommend pulling both and rebuild them.
They generally aren't to far from failing if one goes.

Split boot screams bad cv!

That's the point. He asked how to determine which one. If the wheel turns and the and the trans flange doesn't....

If it does jack up the other side or have someone else turn it and he looks at the other flange.

Did this really need spelling out or am I missing something.

Still could be busted spiders or stripped flange on the trans but one has to start somewhere.

Frankly, if a CV were busted up that bad there should be a lot of play in it.

i did something similar to Seatman with mine... except it was still functional just vibrating under load. One side had much more play than the other - and once getting underneath it was easy to see where the problem was.

KLXD said:

Post #2 is correct. Wheel can't turn through the spiders if the trans is in gear and only one wheel off the ground. If it does it isn't in gear or sumpins broke.

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I think I follow what Wonneber is saying.

Lets just say the drivers side axle is the broken one. If he puts the car in gear (or park), jacks up the passenger side and spins the tire, the drivers side axle could spin thanks to the spider gears in the open diff. Only the tire would remain stationary.

So spinning a tire could be fruitless.

Unless you have a helper to spin the tire while you see which axle is rotating.

Which was why Seatman said jack up each wheel individually.

magus1111 said:

My axle was clicking and let go today preventing the car from driving under its own power...............

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It will be easy to tell what gave, any of the methods will work. You may even be able to just look underneath, something is likely turning to no affect.

With the car in gear (not running), turn the wheel that's up and you may still see something turning s/a outer CV joint, maybe the axel and not the inner joint.
Same other side.
You may have to hold the inner joint with big channel lock pliers.
If the side up is OK I still say the spider gears will spin.
If neither side show signs of breakage you would know it's in the trans.

I've only posted here a couple times. Am I missing something? A bad CV joint? Why repair as they are reasonable with life warranty at Advance Auto. I have had many of these Jettas (6) and still have three. Just replace BOTH axle assemblies. All joints covered. In many years I had one go bad and I've changed (3) sets. Not only did my vendor give me the replacement, but he also gave me the other side as he knew my theory of fix it right or pay for it later. Same with bearings. dl

P.S. correct me if I'm wrong. I have broad shoulders. lol

Many believe the best repair is to replace the joints with new OE style units.
Some have issues with different axle density and early joint failure. Some are happy with replacement units, Raxles and such.
Wonder how the OP is coming, haven't heard anything in 12 days.

disillubber said:

I've only posted here a couple times. Am I missing something? A bad CV joint? Why repair as they are reasonable with life warranty at Advance Auto.
P.S. correct me if I'm wrong. I have broad shoulders. lol

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It's not a question of right or wrong, it's diagnose the problem correctly so you only get the parts you need.
Playing 'let's try this next' gets expensive after a while.
Also don't forget the time spent and running back & forth to the parts store.

wonneber said:

It's not a question of right or wrong, it's diagnose the problem correctly so you only get the parts you need.
Playing 'let's try this next' gets expensive after a while.
Also don't forget the time spent and running back & forth to the parts store.

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I understand wonneber, but my personal opinion (and experience) is; if you have the same usage or time on one part a like part has that same time also. It is likely to fail soon. If a headlight goes out I change them both. Bearings? for sure. If nothing more, it buys you "peace of mind".

If I buy an unknown tdi with above 100k miles with no proof of timing belt change, I will have it changed. It is only the way I am and a personal choice. dl

disillubber said:

I understand wonneber, but my personal opinion (and experience) is; if you have the same usage or time on one part a like part has that same time also. It is likely to fail soon. If a headlight goes out I change them both. Bearings? for sure. If nothing more, it buys you "peace of mind".

If I buy an unknown tdi with above 100k miles with no proof of timing belt change, I will have it changed. It is only the way I am and a personal choice. dl

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I agree with you on some things to change together s/a brake pads on both sides, but head lights?
I've had them stager burning out by years.
My point actually is diagnose it correctly, not guess at it.

Headlights dim with use so they are best replaced in pairs.

As for axles and other left/right items on the car, I don't replace them in pairs personally. Typically the right side of a car is subject to more severe driving conditions than the left so I expect different wear rates for each side. It's not like replacing both axles saves an appreciable amount of time vs replacing them as they fail and they almost always give warnings. But whatever gives you peace of mind, that's the route to take.

With one side of the car jacked up and the car in gear the wheel won't be able to spin unless A it's an auto or B the axle is broken/worn, that was the idea I was on about lol.

Regarding replacing both I tend to find the left takes more beating, I think it's something to do with torque and the axle being shorter? Or maybe it's at more of an angle?

Anyway I don't find the other wears out at the same time or close so generally just replace the one.

Seatman said:

With one side of the car jacked up and the car in gear the wheel won't be able to spin unless A it's an auto or B the axle is broken/worn, that was the idea I was on about lol.

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The OP is looking for what's broken.
Do the automatics have a park pawl? If so it should be the equivalent of the manual trans in gear.