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Repeated bad LF axle - 2001 Forester

I need some advice. I took my car into the local shop this summer because there is some odor from under the hood. They said it was a torn boot on the front axle/CV joint. They replaced the whole axle.



I drove it to Atlanta and back. When I got back, it was clunking on acceleration and right turn acceleration. Took it in and they said the axle was bad. They replaced it.



I drove it to Niagra Falls. When I got back, it was clunking on acceleration and right turn acceleration. Took it in and they said the axle was bad. They replaced it.



I have been driving it for about a month now. Its doing it again. I took it into the shop again. They told me something about too much play in the mount of the axle to the transmission. He pushed the axle up and down and supposedly the slight movement was too much. But when he did the other side it looked the same to me. And he did not sound too sure of himself. He looked mostly frustrated. In fact, it was a different mechanic because the first mechanic gave up.



I’m not sure what to do at this point. If I take it to a trans shop, I have to pay them to diagnose it, then I loose that money if it turns out to be some cheap axles. I personally can’t see any reason for a CV joint to go bad that quick unless it has no lubricant. The axle was running fine before they replaced it because of the torn boot. Any advice?

Where are they getting the axles they are using? Maybe there’s a bad batch of rebuilt axles. Otherwise I can’t explain how you could get three in a row that failed so quickly.

I agree with you. As long as the boots are intact and the joints have lubricant they should last a long time.

Which CV joint (inner or outer) is failing?

A couple of questions. How many miles on the car and does the car see any dirt roads, high water, northern road salt, etc.?

The reason I ask is because the inner joint (DOJ) is fitted onto what is called a stub axle that protrudes from the transmission final drive. This stub axle is splined and the DOJ is also splined.
They should fit snugly together and are pinned in place with a serrated drive pin.

If the inner joint is moving up and down on the splines it’s possible the stub axles are worn on the splines and/or the DOJ drive pin hole is wallowed out. This is not a common thing to occur but it does happen. Just off the top of my head I think I’ve probably replaced 3 or 4 pair of them.
(Bad news is that the transaxle has to come out and be disassembled.)

Hope some of that helps.

I don’t know if this is the case with Subarus, but with many models rebuilt CV axles are simply not reliable. The problem is that the way they rebuild the joints is by installing oversized ball bearings and to do so they bore out the little cavities where the bearings sit. These cavities are usually hardened and after they bore them out the bearings roll against unhardened metal which sometimes results in spectacularly short joint life.

Plus buying a brand new axle is usually not that much more expensive-- the last time I priced one out, the new one was only 10 bucks more than the rebuild.

I live in Michigan so it does see snow and salt. I do not take it off road. It has probably around 100k on it. I can’t remember specifically just now. But I work less than a 1/2 mile from home. I probably put 10mi a day on it.

The mechanic tried to show me how the joint had too much play and pointed to the transmission. But I did not see any play at all when he pushed the axle up. Then he tried to show me the other side when I told him I did not see any motion. He gave a 1/2 hearted attempt to show, but to me he knew I was not buying it and I don’t think he bought it either.

Plus, the main problem I have is that the axle was fine before they replaced it. It was replaced because of the boot, not the CV joint. And you can imagine a torn boot leaves a dirty joint, but it lasted so much longer than the ones I am getting lately…

JMHO here, but I think the drive pin should be eyeballed very closely while moving that inner joint by hand.

When the joint is installed on the stub axle note there is a hole clear through the entire thing. The joint will fit one way or it can be rotated 180 degrees and installed fine the other.
However, there is only one way that it MUST go and extreme care must be used when installing the joint.

It is possible to have the joint 180 degrees off and the hole that is seen may appear to be lined up but in reality it is not. It is off just enough that if one forces the pin with a hammer the pin will be damaged and the joint will not fit tight on the stub axle.
If you eyeball that pin it MUST be rock solid in the stub axle hole.

My memory is fuzzy as it’s been a few years but it seems like the last one I did involved someone having both halfshafts replaced, the shop got the holes mismatched on both sides, and they proceeded to pound the pins in with a hammer.
The results were flopping halfshafts and 2 ruined stub axles; the latter of which required tearing the transmission down.

I don’t know if this is any help or not and sincerely hope there is not a stub axle problem, but if the car were mine that’s the first thing I would look at. Without seeing the car that’s my best guesses.

This is what I’ve been waiting for, someone who has some knowledge of Subarus. I wanted so much to ask, “Does your mechanic understand Subaru,” but I resisted, because Subarus are so common now, and I thought anyone could work on them, at least for the simple things, like an axle replacement.

I’ve been lucky, perhaps, because I had my Subaru’s front axles replaced by an independent mechanic who does not specialize in Subaru. I can only assume he followed the repair procedure on his online service program to the letter, because I’ve had no problems with the axles he installed, and they’ve been on the car for nearly 50,000 miles.

I also patronize an independent mechanic (the Subaru Guru) who works on nothing but Subarus if I think I have a Subaru-specific problem, such as something with the AWD system or the engine.

Maybe you need to take your car to someone who understands Subaru vehicles, or is at least willing to look up the correct axle replacement procedure on the Internet and follow the instructions.