CV axles with Tein springs
 

I have a 2004 SL with 103,000 miles and starting two weeks ago I installed Tein springs and replaced everything else in the front end except for the struts which didn't need to be replaced. A Megan Racing FSTB and a Progress rear sway bar and Moog end links went in as well. The rear wheel bearings were noisy so I also got a complete set of front and rear Timkens and installed the rears.

I did this in two stages. 1st stage was springs, seats, front sway bar bushings/endlinks, FSTB, and RSB/endlinks. Fantastic. A week later I did the 2nd stage which was front lower control arms, tie rod ends, and rear wheel bearings. After taking off the wheels I found a newly split right inner CV boot. I put it down to age and decided to replace both sides. I got a set of "new" Carquest axles from a local Advanced Auto Parts and installed the right side. I wasn't able to get the left side out of the hub so I left in in. After I finished the install there was a shudder during initial acceleration and a bad vibration at any speed above 65mph which I thought could be an alignment issue.

I brought the car in for alignment and also had them install the left axle, front wheel bearings/hubs, and re-balance all four tires but the shudder/vibration is still there.

With all the new parts, alignment, and balance it has to come down to the cheap Chinese made axles, right? I drove the car for a week (350 miles) after the 1st stage before noticing the split boot and everything else was fine. The trouble started only after putting in the cheap axle. I have already emailed Raxles and Marty replied saying that they don't have anything for our cars anymore.? That leaves only one option, new Nissan OE axles for about $450 per side.

Am I missing something? I have read about bad motor mounts but I highly doubt that because there was no shudder/vibration after after I did the 1st stage with the OE axle, even before alignment.

I think I know what I have to do now but any input would be appreciated before I spend another $900.

It's the axle. Unfortunately, this and uneven tire wear also come with being lowered for our cars. Just exchange it at the same autoparts store that you bought it from. Most come with a lifetime warranty. My local store has them for under $100. No use spending extra for the oems if you plan to stay lowered because they will see the same fate.