i took the car in for a rear axle boot leak (lot of grease caked all around) and they replaced the axle. the left rear boot is also leaking, but much less so than the right side. so for the left, is that something where 'just' the cv joint' can be replaced (since i am catching it early), or will they need to replace the entire axle. also, is there any issue with driving a car with a new axle on one side only? i thought i noticed a difference in road handling after the repair. thanks all for your feedback.

 

if your bad axle was bad enough, you might notice a difference in handling.. you have to remove the axle to put a new boot on it, I would check the prices and compare, unless you are going to do it your self...

 

So there are a few parts to the axle.

Inner CV
Metal shaft
Outer CV and spline

The boot covers the inner and outer CV's which are packed with grease. When the boot tears, the grease is then shot out and makes a real mess.

The CV does not need to be replaced unless the joint has ran completely dry and the joint breaks or has serious damage from metal on metal contact.

In your case, pull the axle out, remove broken boot, clean and repack with grease, reinstall new bott and be on your way.

 

People often choose to replace the whole pre-assembled axle (shaft + 2 CV joints, including boots) rather than just one boot, just because the axle assembly is built somewhere with cheap labor and you or your mechanic's time value make it the best option for financial reasons only. It amazes me how cheap these things can be. But often the quality of the replacement parts (either rebuilt or built new in China) will not be up to the old OE stuff you have already.

So I usually try to avoid replacing good old parts, especially in cases like mine where I knew many parts were still perfectly good:

When I got my '91, during my new-owner full inspection, I noticed CV joint grease under the car. After cleaning things carefully, I determined that the boots were intact, but it was leaking out of the small end of the boot. Over time (20 years and 160k miles), the grease had liquefied significantly, and the boots, although intact, did not fit as tightly over the shaft as they once had.

My solution was to pump in new grease, with an injector thing I rigged up and stuck through the gap between the shaft and the small end of the boot. As I did this, the old grease poured out, being displaced by the new grease. I then put new clamps on the boot inner ends. Did this to all 4 boots. Since the axle shafts and CV joints themselves were fine, I got the benefit of keeping the original parts. 5 years and 20k miles later, all is still fine.

If I had a tear in a boot or clunking/loose CV joints, different story of course. But just because you have grease leaking, you may not have a boot tear.

so to answer your questions more directly, it depends on what is really wrong with it. It could be that there is nothing at all wrong with the shaft and joints. In that case, you would not expect a handling change, because it should be the same (unless the replaced side is worse than the original). If old grease is coming out, at the very least, new grease has to go in, and future leaking needs to be prevented (what I did). If a boot is torn, it needs to be replaced, requiring axle removal. Messy job, at which point you may opt to replace the whole axle assembly. But it is possible that just the boot needs replacing. It is also possible that enough grease leaked out or enough dirt got inside that the CV joint bearing itself (big ball bearings and thick races) has been damaged (will be easy to see upon disassembly and cleaning; maybe can be determined on the vehicle if motion is rough or too loose).

 

I guess the reason i am asking is that awhile back I was given a quote by one indie shop for $360 to repair leaks of both boots (with no mention of an axle needing to be replaced). The quote was based on just eyeballing the problem -- nothing was taken apart. The shop I eventually took it to for repair (I was there for something else and just wanted to get it done) wound up replacing the axle on the side that was leaking the heaviest. I left expecting a boot repair and returned to find a new axle installed. Which is fine. I didn't have them fix the minor leak, which I figured could wait. As far as I know I got an OEM axle. The labor was around $100 and the total for the job was slightly more than what I was quoted by the other shop to fix both sides. I am not sure what to think. I am wondering if the other shop, once they got in there, would have said "we need to replace the axle". Also from what I am reading, it sounds like the longer I wait to repair the other side, the more likely it is that I will need to replace the axle on that side as well. Since the leak is minor at this point, hopefully they can just fix the boot.

Any additional comments appreciated. I will look over everything already posted here to see if that can help with deciding what to do about the other boot repair.

Btw, I have driven the car long enough now, and no, there is no difference in handling due to axle replacement on one side.

Also, if it helps with feedback, the mechanic said the bearing(?) was basically mush. I was told it was easier to replace the axle, that trying to rebuild it would entail more labor charge etc. I am not a DIY, so can only go by what I was told.

 

Thanks. Any idea what would be a areasonable charge to do this type of repair on a first generation LS400? Repair minor CV leak on one side only? It should not be completely dry or have had metal to metal contact. Car has low mileage for its years...around 100K.

 

The "new" axle that was put in 4 months ago is leaking some. I was told it just needs a clamp of some kind. This repair is under warranty, so should I ask for a new axle? Or let them put on a clamp. Sounds like jerry rigging to me. The repair was not cheap (I do not recall the exact amount, but around $500 for the part and labor) so not exactly a satisfied customer.