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I'm not a mechanic. Far from it. I'm hearing anecdotes that XIs have higher CV boot failure rates. Is this true, and if so why? I wonder if lower with spring and stiff shocks will lead to higher CV boot failure. Anyone more technically inclined in the know?
 

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no. its just the rubber boots going bad then ignored. water and sand got in breaking the CV joints.
usually if its just start to tear, and you catch it on time to regrease and repack, it will last for a long time.
 

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Sir, you have presented a question where what you will receive will be ambiguous answers at best. I have followed this mystery for a couple years and would conclude, when lowered - results may vary. There are many variables here. First, any CV's, in any car, will wear from use and mileage. Our XI's don't necessarily have a weak component but like others, should the boot rip or clamps loosen, the lubricating fluid seeps or actually slings out causing the joint to run dry and fail. Boots being thin material that flex and stretch have a limited lifetime. Keeping an eye on boot condition is recommended for all CV cars.

When the car is lowered, the drive position of the axle changes from a slight downward angle to horizontal or slight upward position. Some will contend this is the CV killer as not the factory engineered "normal" angle. I would suggest this is questionable as when the angle changes, it still remains within the normal operating range of motion. Think of driving over bumps where the axles are pushed upward into the "lowered" position and then return to the normal drive angle. CV's don't operate constantly in one position, they are designed to work in a range of axle motion. If not, we should avoid hitting bumps.

Lowering creates concerns such as wheel camber and and proper alignment that must be observed. Additional stress from stiff springs, struts, shocks and low profile tires should be considered. Strut towers and rear shock mounts need to be modified to handle the additional applied forces. The CV's however, are not affected from stiff suspension forces.

Personal observation - I think owners lower their car and simply miss the axle/boot condition. Their tired CV fails 500 miles later and the myth was born. Mushrooming the strut tower, tearing the rear shock mount and spine injury may be an affect but not CV failure. Too many owners have success lowering these cars where they payed attention to drive and suspension components involved. They report long term mileage without incident.

I believe when some install "sport" suspensions and big-ol', wide tires, they drive them hard for the pay-off. That's dandy 'cause now they gots 'em a race car but hammering the original axles ripping around corners and dropping the clutch may play into CV failure? BMW targeted this market offering the M3. Making one out of your XI is subjective and as stated in the opening paragraph - results may vary.
 

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As far as higher CV boot failure, I would say YES. The front axles at least. The driving angle of the Front CV's are constantly changing when you are going around corners, going over bumps etc.
The rear should have the same lifespan as a typical RWD BMW.

I think White_Knucles hit the nail on the head when it comes to increased wear from having wider wheels/tires, racing around corners, etc. People who lower their cars and put aftermarket wheels on their cars tend to drive them a little harder in most cases. This will increase the wear over a typical stock car with average driving. It is common on FWD VW's to have problems with wheel bearing and CV wear when running wheels/tires that are wider than stock or have more positive offset putting added stress on the bearings.
 

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i think white knuckles is right on with it!....my driver side tore not that long ago...i think i caught it in time, got it repacked an new boot...led to me to believe, my passenger is was prob on its way as well...so i inspected it...i could see cracking starting to show....so i went ahead and got it replaced.....
now i'm worried that i should have just done that with the driver side first time around....argh...
 
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