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Can a bad axle ruin a center differential?

I have an 01 Subaru Outback (120K miles). Last summer, I had a front axle replaced (ripped boot), but it failed in four months. The clips on its boots fell off and the inner joint got contaminated. The joint failed (felt like the wheel was going to fall off), but the car was drivable. I got towed back to the shop and they replaced the axle. Shortly after, I started getting a toc- toc noise when turning hard to the right and applying power. The mechanic looked at it and we dismissed the CV joint as the noise did not seem to increase with speed, and disappears with a second person in the car. After some research on the web (OK, this community) I suspected the center differential (viscous coupler). Some of the causes are mismatched tires, low pressure, etc. What about this axle failure? I am not looking forward to $1000+ to repair, especially if a faulty part as the cause. Any thoughts? Oh, I just had all struts replaced, so that rules out strut bushings, ball joints and other front end connections as the mechanic was looking out for that as a source of the sound.

Possibly…but I ALWAYS take my AWD cars to the dealer for evaluation. From there I shop around for the best price with someone I can trust. These babies are too specialized for mechanics without lots of dedicated experience to evaluate. Just my humble opinion.

Are they using remanufactured axles? If so, I would suspect the outer CV joint. I have never had any luck with a remanufactured axle.

No, it was (both) were new axles. The mechanic is pretty trustworthy and I have been using him for years.

You state the axle (singular) was replaced and was replaced again after the boot came loose. That only accounts for one side.

There are several possibilities here but there’s not enough info known to make much of a guess. Offhand, it sounds like a faulty axle to me. The reason the noise may go away is because the stance of the vehicle can change with additional weight in it and this alters the position of the CV balls in the race.

The CV boot clamps failed on a new factory axle in 4 months?? Not very likely…Sounds like rebuilt junk…I agree with keith on this…

The OP needs to clarify this. They state both axles were new but do not say that axles on both sides were replaced; only that one was replaced originally and the same axle was replaced a second time is the way I read it.

For a grand I would hope that any axle would be a brand new Subaru OEM part because it sounds way overpriced for a reman including both part and labor.

The clamps should not have failed even on a reman unit. Given the torn boot and dislodged clamps I’m curious if this car is seeing a lot of use on rough dirt roads and whatnot.

Sorry to be coming back to this thread after so long, but I forgot my log in. All the replacements were on the passenger front. From what the mechanic said, it looked like the clamps were not crimped correctly. Not OEM or rebuilt (although Click and Clack say remans are actually better). The original cause of this thread was solved by replacing the axle yet again and, hold on to your hats, the driver side was just done. More problems with the heads (see recent post). My mechanic has complained about the quality of car parts recently and has changed vendors when they won’t stand behind part failures. Race to the bottom it would seem.

I had a 93 Saturn that went through three axles in the first year of its life (CV boot failures due to friction overheating of the antilock brake sensor ring - it had worn down to almost nothing by the time they noticed it)

ok4450 - car is not used off road at all (unless you consider a 700 foot gravel driveway off road.)

@Gilbane did your mechanic install brand new Subaru axleshafts?
Or brand new aftermarket axleshafts?
Personally, I have had extremely bad luck with brand new aftermarket axlehafts. In some cases, they barely lasted a year before making noise.
On the other hand, I’ve had pretty good luck with aftermarket remanned axleshafts. One time I took my axleshaft to a local shop to be remanned. They rebuilt it for $40 (inner and outer joints, boots and clamps) and several years later it’s still going strong and is quiet!

The problem was likely due to the driver’s side axle that was not replaced originally. As to clamp crimping, I’ve never seen a problem with that unless it was botched by a DIYer at home or by a shop that got a little careless. Never seen a problem with clamps on new or reman axles.

I think there’s some truth to what your mechanic told you about the quality of reman parts. Over the last couple of years I’ve had some repeat reman axle shaft failures (some inside of 2 weeks) and in one case replacement shafts were re-ordered several times. Opening the boxes on the counter before leaving with them I discovered that all of the re-orders were bad right out of the box. The third time was a charm and led to a shaft that was actually good.

For what it’s worth, many years ago I knew personally 2 guys who lost their jobs and found employment at a large parts remanufacturing facility in OK City. They’re both great guys to know but have no mechanical knowledge and don’t even change the oil in their own cars but there they were; assembling car parts with no knowledge at all of how they worked.
In another large engine building facility in OK City (now defunct) they used to run ads in the paper for “Engine builders, no experience necessary”. What does that tell you? :slight_smile: