2000 Legacy L Wagon - Mysterious Vibrations After Impact on Freeway

[dirty_mech]

2 hours ago, forester2002s said:

You may have already done this, but if not I would change the rubber-boots and clean out the CV-joints.

Most new boots come with replacement grease. It's fairly easy to completely disassemble a CV-joint, and to clean out all of the existing grease. Once clean, it's easy to inspect the mating surfaces, and to see if there is any surface-wear. The Subaru OEM CV-joints are a thing of beauty, and are well made.

Add the fresh grease, reassemble and re-boot.  This might help with problematic vibrations. But in any case, it's a labor of love, a kind of Zen thing.

So just cleaning and regreasing them can make them work more smoothly and eliminate vibration!? 

I'm curious if any of the internal parts are replaceable, in the event I do find wear... 

But it sounds like you're saying they never really go bad as long as the boot doesn't break.  So maybe a rebooting and regreasing is really all I do need.

Still wondering about those 20+ year old wheel bearings.  I wonder if I can reduce vibration even further by replacing them...

Here's a guy who has a great technique for cleaning out old CV joint grease with compressed air and brake cleaner:

 

Edited August 15, 2022 by dirty_mech

[idosubaru]

1 hour ago, dirty_mech said:

So just cleaning and regreasing them can make them work more smoothly and eliminate vibration!? 

Absolutely.  I've done it.  Massive vibrations, had to vary the speed constantly basically undrivable, rear view mirror shaking so bad you couldnt' see out of it.  Regrease, good to go. 

 

1 hour ago, dirty_mech said:

 

I'm curious if any of the internal parts are replaceable, in the event I do find wear... 

I think Marshall from MWE used to get some new parts, unless I'm just mis-remembering.  I heard him say something over the phone to me one time about new parts 20 years ago, so there's a lot that could go wrong in that recalling? I haven't heard of people really rebuilding with new so I assume they don't exist now or it isn't cost effective. 

 

1 hour ago, dirty_mech said:

 

But it sounds like you're saying they never really go bad as long as the boot doesn't break.  So maybe a rebooting and regreasing is really all I do need.

Axles can wear without breaking/exposure.  Usual suspects - high mileage, type of driving, etc. 

 

1 hour ago, dirty_mech said:

Still wondering about those 20+ year old wheel bearings.  I wonder if I can reduce vibration even further by replacing them...

 

I doubt it. If wheel bearings are vibrating I don't think they're mechanically forgiving enough to tolerate being out of spec like an axle. I think they have very limited lubrication, they aren't sitting in a huge cavernous supply of grease like an axle.  There's more ball bearings, less grease, in a tighter area that's not designed for any play or articulation like an axle.  They're not going to click for 50,000 miles like an axle but still work fine.  They're going to get worse quickly and fail.  I doubt they have some phantom vibration unless it's escalting over time. 

I think Fairtax (username) had a troubling vibration on his EJ vehicle that he couldnt' figure out for years replacing multiple items.  He ended up accidentally repairing the issue when he replaced....i think it was the steering rack...for some unrelated reason.  If you can find that ancient thread, that might be worth looking at. Fairtax 4 me or something along those lines.

[dirty_mech]

Thanks for all the great info, Idosubaru!  It sounds like I'll be changing out the boots and grease on all my axles in the near future.  I want to make those puppies last as long as possible.

Glad I don't need to sweat the wheel bearings.  I've done one of those on a Toyota Corolla before and it's not easy even on basic models.  I'll wait until one of those fails to replace it.

The vibration I have is fairly mild right now.  I'll take my time greasing the axles and see if that does it.  If not, I'll look for that Fairfax thread on the steering rack.

[idosubaru]

4 hours ago, dirty_mech said:

Thanks for all the great info, Idosubaru!  It sounds like I'll be changing out the boots and grease on all my axles in the near future.  I want to make those puppies last as long as possible.

Glad I don't need to sweat the wheel bearings.  I've done one of those on a Toyota Corolla before and it's not easy even on basic models.  I'll wait until one of those fails to replace it.

The vibration I have is fairly mild right now.  I'll take my time greasing the axles and see if that does it.  If not, I'll look for that Fairfax thread on the steering rack.

Sure thing. I could be wrong, maybe bearings can vibrate. But I’m not.  just kidding, who knows with mechanicals right 

Ive cut open boots and the green grease pours out like water. Kind of crazy it gets that nasty 

Here’s a his user profile, fantastic guy. Hasn’t been around in years hope he’s okay, and this assumes he never changes accounts/didn’t have two accounts:

https://www.ultimatesubaru.org/forum/profile/23241-fairtax4me/

[heartless]

generally speaking, wheel bearings dont vibrate enough that the driver notices vibration... 99.8% of the time it is noise that is noticed first - whining, growling.. the sound changes with load force.

Even our old 95 Dodge Ram made growling noises before the bearing gave out... and it was a pretty spectacular failure, lol  she locked up almost completely... and when we went to change it, the balls fell out of the housing... it was that bad.