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Discussion Starter #1
You were seeing the rear differential and independent rear suspension. The axles are attached to the diff with CV joints Corvette style. Solstice is rear drive so it has driveline components at the back of the car.
During the last 210,000 miles on the only front wheel drive car I've owned, I've had the replace the CV joints twice. Now they've just started the old, familiar song when I turn left. But I've been hoping that I'll just drive it till the Solstice comes out and never have to worry about them again. And then I read this! Tell me it's a whole different thing on rear wheel drive and they won't need to be replaced more often than that darned timing belt. Tell me I won't have to make the choice of paying $200 to get a torn boot replaced or $400 later to replace the CV. Say it ain't so!
 

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You shouldn't have to replace them as often. CV joints on front wheel drive vehicles fail more often for several reasons. They are exposed to more grime if you have oil leaks, etc. When the boots get oil on them, then road grit sticks to them and basically sands away the rubber. If that isn't bad enough, your CV joints on a front wheel drive car have to swing through wider arcs because the wheels have to turn and move through their suspension travel. This causes more wear on the joint itsself, and compresses and expands the boot more as well.

So, in theory, you shouldn't have to worry about replacing your rear CV joints or boots unless they are designed poorly.
 

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I'm just wondering - what's the big issue with CV joints?

EVERY DRIVEN, INDEPENDENT rear suspension has CV joints. That means:

Corvette
Honda S2000
Miata
VUE 4WD (even though it is primary FWD)

and a butt-load more...

The only way you don't have them is with a solid rear axle (like F-car, SSR, Trailblazer/Envoy, etc.)

Solstice has a double wishbone independent rear suspension. It will have CV joints (although it is technically possible to use hooke joints, the vibrations that could result at highway speeds during ride travel would preclude such a stupid decision).

There's just no other way to get the power from a stationary differential to articulating hubs...
 

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The CV joints may not need replacement as often on some cars as they are on others too. However, I do not really see any way around them if you want an independent suspension. You have to get the axles to move independently of each other as the wheels travel up and down in the back.

That said, one of the negatives of the FWD setup is that it puts a lot of added stress on the driveline components. Not only do they have to handle acceleration, but they also have to handle steering (as was mentioned) as well as all the weight of the full driveline which is sitting right above. On a rwd car, those CV joints will be out back, and won't have to handle the engine weight, or the steering duties and stresses. They should hold up longer.
 

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Fformula88,

I don't get the comment of "weight of the driveline directly above". The drive axles do not support the weight of the engine.

Neither does the position of the engine mass have anything to do with the amount of driving torque/abuse the drive axles take.

Can you specify?

Re: Steering, yes - articulation is the main reason that CV joints, type and strength, that there may be less life in a FWD than RWD. The compound angles from steering and ride travel far exceed what a RWD CV joint has to withstand.
 

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The joints in the rearend should last nearly as long as the U-joins in the drive shaft. They do have a greater angle of deflection than the drive shaft, and that will cause a little more wear, but it's the deflection in two axis, often at the same time, that tear them up in a FWD car.
 

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Discussion Starter #7
The worse part of my fears have been put to rest. I work with a guy who has a supercharged Miata and we talk about our cars a lot. I don't remember him ever complaining about replacing his CV joints. Some how I just didn't put the independent rear suspension and CV joints together. Just out of curiosty, did a Jag have them back in the sixties only with a different name?
 

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solsticeman said:
Fformula88,

I don't get the comment of "weight of the driveline directly above". The drive axles do not support the weight of the engine.

Neither does the position of the engine mass have anything to do with the amount of driving torque/abuse the drive axles take.

Can you specify?

Re: Steering, yes - articulation is the main reason that CV joints, type and strength, that there may be less life in a FWD than RWD. The compound angles from steering and ride travel far exceed what a RWD CV joint has to withstand.
Oh, I know the weight isn't directly to bear on the axles, but I guess I was having a brain cramp at the time. Your right, as it would not directly affect the CV's. The best reasoning I could possibly think of would be the extra mass over the steering and driven wheels could cause more stress on the axles when going through turns, but again it would not be directly related to the weight, but more so to the turn and power being added in the turn. I'll shut up now! :smile
 

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Fformula88 said:
Oh, I know the weight isn't directly to bear on the axles, but I guess I was having a brain cramp at the time. Your right, as it would not directly affect the CV's. The best reasoning I could possibly think of would be the extra mass over the steering and driven wheels could cause more stress on the axles when going through turns, but again it would not be directly related to the weight, but more so to the turn and power being added in the turn. I'll shut up now! :smile
dont sell yourself so short just yet. this is just theory, but more weight directly over suspension will mean more suspension travel. FWD CV joints have to deal with that up n down motion as well. i dont know if it matters, but while additional mass might not affect the CV directly, the pogo resulting from that mass may. :thumbs

as far as steering having an affect, IIRC its usually the inner boot/CV that fails most often. and, the inner/CV only response to steering inputs is to slide on the splines. so i would think any damage or wear due to steering would occur at the spindle where the turning axis is.

or, i could be completely wrong. im just bored and feel like posting all my thoughts. i think i put my brain in backwards this morning. :jester
 

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Thats it! The heck with FWD and its failing CV's! RWD Roadsters 4-L! :lol :jester
 

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I'm with Fformula88 :cheers

The suspension travel thing isn't exactly right - if you have one end of the car with more suspension travel than the other, then pitch becomes a significant problem.

Front and rear suspension travel for many cars can be different, but not by very much. Usually they are only different by 3/4 inch or less - total travel.

Regardless of FWD or RWD, the vast majority of cars have more ride travel in the rear - specifically because if the ride is tuned properly for flat bump management (the old "flat ride tuning"), you need more travel in the rear to handle the frequency difference and space the pitch and bounce centers properly. That's just how it works out.

Hood downvision also tends to limit front ride travel to more of an extent than the rear, but that's probably not the overriding factor.

The pure fact of the matter is if you set up a vehicle with limited front travel, you can probably get away with it, and while riding hard and crashing into your bump stops, overall motion is reasonably acceptable.

If you leave the front alone and limit the rear travel, OUCH! You'll feel like you're getting your a$$ kicked on every moderate bump, and the car gets into this rear-high pitching mode that takes several feet AFTER the bump to settle.

That being said, the articulation and stroking of the outer and inner CV joints respectively is decidedly better in a RWD than a FWD situation.

Bottom line: there should be a much better situation (excessive power notwithstanding) with a RWD CV joint than a FWD CV joint.
 

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(excessive power notwithstanding)
side note: i just replaced my axles last week with upgraded "bulletproof" units. i thought i had a torn boot on my stocker, but it turned out that the boot had just been forced off. :jester :thumbs
 
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