CV Axle Shudder

Hi All,

I have a 2001 Jetta TDI with almost 275,000 miles on it. To my knowledge, the front CV Axles were stock. I just replaced them with new ones from NAPA, and can hear them hum and feel them vibrate between 1800-2000 and 3600-4000 RPM (mostly in gear but also in neutral). I made sure to grease the bearings (w/ Redline CV-2 Synthetic ) before mounting them, made sure the gasket sat in place, and torqued the triple square bolts down to 30lbs.

I've taken the old ones on and off before when replacing the turbo and have never experienced this side effect; since they're new axles, do they have to be broken in some how?

Not sure, but just from reading here, it seems some replacement axles are hollow, believe stock are solid.

NickScott said:

I just replaced them with new ones from NAPA, and can hear them hum and feel them vibrate between 1800-2000 and 3600-4000 RPM (mostly in gear but also in neutral).

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There's your answer. You replaced your axles with Chinese garbage. Axles do not require "break in". I have no clue why people put Chinese garbage parts on their car. Garbage parts seem to always cost you more in the long run than putting quality parts on your car the first time.

I bought some from idparts and didn’t have that problem. The part you got may have some defects. New complete axels cost me mid 200’s.

https://www.idparts.com/advanced_search_result.php?keywords=Complete+Axle

I’m sure some other vendors have equally good products. I try to limit my purchases from the Walmart’s of automotive to only those few things that it’s almost impossible to screw up.

Sent from my iPhone using Tapatalk

When I did my 5 speed swap I put O'Reillys CV driveshafts in my 2003 wagon. They did seem to vibrate a bit and make a bit of noise like you are experiencing. I recently ended up replacing the PS axle because the CV inner bolts kept vibrating loose. (other things vibrated loose as well) The new axle seems better. The replaced it under warranty.



I considered using used axles from the junkyard but they wanted more than the new ones cost. I did use one O'Reilly axle on my sedan and it has been fine for a year.


My opinion is that the aftermarket axles can be hit or miss.

I rebuild mine, not a bad job.
Vibration could be loosening bolts, or out of balance shaft. I find the bolts like to come loose due to grease that's difficult to get out.

I'd re-torque the bolts to be sure and consider rebuilding the old axles in case.

Awesome, thanks for all the replies. I think what I'll do is keep an eye on the bolts for a few weeks and then put some OE quality ones on as soon as my wallet recovers from the holidays.

Newbie question: relative to CV axles, what's a core? I see ID Parts lists on their axle descriptions, "no core charge or core refund", which is the same thing NAPA has for their new ones - but for NAPA's remanufactured axles they charge and return a core deposit (which is originally why I went there, on a recommendation).

Another newbie question: Any idea how to tell Chinese garbage apart from OE quality, besides it coming from a chain store? Is it by brand? Or anything that doesn't list "OE quality"?

I put some cheap ones on when I thought my CV axles were going out (they weren't). The vibration went away after 6 months or so. I've probably got 10-15k on them so far and they seem to be working ok.

For years, we bought and rebuilt axles with a local company, Trussells, in Springfield, Mo. However, the Chinese axles that were 30% cheaper, drove them out of business. We actually brought new Chinesium axles to them and they would repair them. That is, as long as the could be properly rebuilt.

There were a few requirements to get axles repaired:

1) It had to be able to come apart correctly. You would not beleive how some were built, with the CV joint non-removable.
2) The right side axle is supposed to be a hollow shaft. The Chinese axles are solid shafts, For both left and right axles. The reason for the hollow, longer right shaft is to keep the shaft from 'whipping'. If there is any imbalance in the shaft, a solid shaft will bend more readily than the hollow shaft, which is stiffer and yet lighter than the smaller diameter solid shafts.
3). The bearings and cage need to be tight and should require some force to deflect the CV joint on the axle. When we did get a Chinese axle that was otherwise properly built, but the action of the CV joint was loose, our rebuilder would take the CV joint apart and install oversized ball bearings. CV joints, like Timken style bearings are supposed to run with a preload, which effectively stretches the bearing cage and makes a light, long-lasting axle. This is what Trussells used to perform for us, until their demise, 8 years ago.

Since then, we are working with another company who will take in repairable axles on a core exchange basis. Their work is warranted and they send out their built axle with return label. DO NOT expect a junk Chinese axle to be accepted for core.

Bluntly, we have found NO suppliers of quality CV axles from any of the chain stores, including O'Reillys, Auto Zone, Pep Boys, Napa... that carry a reliable axle shaft. Instead, we work with a company who has rebuilt axles, drive shafts, steering sectors and rack and pinon sets for nearly 70 years.

Let us know if we can help.

NickScott said:

..............Newbie question: relative to CV axles, what's a core?............

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For any part, a core is simply your old part. New part, no core, rebuiult they want one to rebuild.

NickScott said:

............Another newbie question: Any idea how to tell Chinese garbage apart from OE quality, besides it coming from a chain store? Is it by brand? Or anything that doesn't list "OE quality"?

Click to expand...

Due diligence, often simply the price. For ebay, Amazon, Alibaba this info can be near impossible to get. OE quality is a meaningless phrase.

I think the true objective on the hollow longer right half shaft is to have a shaft that has the same torque stiffness compared to the shorter left solid half shaft. Having the total mass being the same would be a bonus, but I'm not completely sure it is. It would be as close to the same as they could make it, I am sure.

Identical torsional stiffness prevents torque steer and keeps the differential from having to absorb the strange effects that happen when one half shaft winds up. With unequal torsional stiffness, the weaker half shaft will act like a spring winding up and then passing that torque back into the drive train when you let up on the go-pedal, have a wheel slip, turn around a corner - anything that will allow the half shaft to spring back. And you really don't want to find out how much fun that is when you are going around a corner in slightly slippery conditions.

Solid right side half shafts - the hallmark of C.R.A.P.

Cheers,

PH

My first experience with replacement axles was not good; they were cheap, Chinese and mediocre. They went on at 372k miles and came off with 446k miles.

Fortunately, I saved my original ones -- I usually do not save old parts but I did that time. I asked Eric Merker to rebuild them for me and install them. I ran them till 572k miles and then got NAPA axles. One of those was replaced (under warranty) 6k miles later.

At the point, the NAPA axles are functioning properly after about 150k miles.