New axle vibrates. Bad engine/tranny mounts?

[alaskanjer]

I bought a pair of Empi axles and replaced the drivers side.

 

I know, searching told me that OEM or MWE are the way to go but I cant afford Subaru at the moment and MWE never returned my calls. Also, I live in Alaska so shipping original and core will double the cost of the MWEs. Local salvage yard has some subaru axles, but none with 50k or less.

 

Soooo It seemed Empi was the next choice and I bought a pair of those. I got one installed and it vibrates at speed for a while (about 5 min.) and then it seems to go away.

 

Searching further I ran across the advice to replace the motor and transmission mounts too? The vibration might be from worn mounts and the old axles had enough slop to hide it. Does this seem right?

 

It is a 98 outback 5 spd. with 200k.

 

Also, should I re-boot the other side that didn't tear a boot, or should I be happy that I got 200K out of it and not try to nurse any more life out of it?

[alaskanjer]

Maybe i should clarify: "at speed" means starting at about 50mph, worst at 60mph, and becoming less noticeable over 65-70 mph.

[jp98]

Maybe i should clarify: "at speed" means starting at about 50mph, worst at 60mph, and becoming less noticeable over 65-70 mph.

 

Have you had your tires balanced and alignment checked?

[98obster]

what are you saving the other one for? vibration might go away after you install the passenger side.

[alaskanjer]

Alignment was done last spring, about 12,000 miles ago.

 

Tires have about 20K on them and were balanced when new, but not since then.

 

I haven't installed the other one yet, because it will be easier to return if it is the fault of the Empi axles.

 

I'm sure it is at least related to the axle I installed, because the vibration wasn't there before and it showed up the first time I drove it after changing the one axle.

 

I think mostly what I am asking is this:

 

Is it likely that the new axle is making another existing problem (like maybe worn out mounts) more obvious?

 

Or is it just that all non-Subaru or MWE axles are so substandard that I should expect them all to have a high probability of producing vibration like this?

[hankosolder2]

Why not contact the supplier and see what their attitude is towards returns?

 

If memory serves, the axles are symmetrical, so could you install the 2nd Empi axle on the driver's side as a test?

 

For what it's worth, I used a pair of cheapie NAPA axles on a '94 legacy with no issues whatsoever. YMMV.

[ferox]

I got one installed and it vibrates at speed for a while (about 5 min.) and then it seems to go away.

 

Do you feel the vibration through the steering wheel or somewhere else? Did you massage the DOJ boot to get the grease mushed into the bearings before install? EMPIs are made in Taiwan to tight tolerances; however, they don't necessarily take the time to get the grease into the bearings adequately. This means that sometimes the Double-Offset Joint (the joint near the transmission) can bind until either the grease works it's way into the bearings through use or there is adequate wear or both.

 

There are plenty of other places that can cause this vibration but the DOJ is the first usual suspect when vibration occurs after an axle shaft replacement.

 

Searching further I ran across the advice to replace the motor and transmission mounts too? The vibration might be from worn mounts and the old axles had enough slop to hide it. Does this seem right?

 

It is a 98 outback 5 spd. with 200k.

 

Bad Trans/motor mounts are more typical of the ea81s and possibly ea82s. The ea81s had tiny trans mounts and wore out easily and quickly, not to mention that they are all old and the cars were probably abused in 4WD at some point in their lives. A '98 Outback has more robust mounts. With 200k they may need replacing if it has never been done, but that is probably not your problem in this case.

[Fairtax4me]

What was wrong with the side you replaced? If it was just a ripped boot repack it put a new boot on and put the OE back on the car. Send the empi axles back.

 

Also, the extra cost for MWEs, worth it. Ground shipping isn't that bad. USPS parcel post is usually half what FedEx or UPS charges. I shipped two cores back FedEx ground for under $20.

[idosubaru]

positive the axle nut was torque down tight?

 

wheel is all good? axle pin was reinstalled on the trans side?

 

most likely the axles, i would be surprised (i'm internally questioning the person that told you this in regards to subarus) if it's some differential equation linking axle condition to mount condition, etc.

 

1. reboot your original axles. ignore mileage, boots are cheap and if you can replace an axle, replacing the boots is no big deal. do that to the existing axle now before it degrades and your forced to install another possibly subpar axle.

 

- i've rebooted some that had been broken, driven on, and vibrating terribly - they are still working fine, quieted down fine after cleaning and regreating/rebooting.

 

2. buy a used axle that's origianl Subaru OEM (you can tell by the boots, bands, and color of the axle cups) and reboot it. ignore milage. i'll take a rebooted 100,000 mile subaru axle any day of the week. i get them for only $25-$33 around here, reboot and you got a like-new axle for $50.

 

you can even use the 2001 newer axles that have the tone ring on the axle, just knock the ring off and install it like normal - your tone ring is on the hub and not needed on the axles. also the newer axles have a more robust outer side CV boot with more convolutions.

 

3. get MWE

 

after many wasted hours and stranded vehicles (when the joints completely exploded, which i've seen), i no longer waste time on aftermarket axles.

 

though some are saying the EMPI's are good, i have no compelling reason to use them with 3 perfectly repeatable solutions mentioned above.

Edited March 26, 2012 by grossgary

[CNY_Dave]

If the rim-rotor mounting surface is crusty (or rotor-hub) you can get a balance-like vibe that seems to come and go.

 

 

Dave

[1 Lucky Texan]

If the rim-rotor mounting surface is crusty (or rotor-hub) you can get a balance-like vibe that seems to come and go.

 

 

Dave

 

 

never thought about this, but seems perfectly possible.

 

I also would like to know if the axle nut was torqued with no weight on the wheel.

 

 

But if there were no vibration before, seems unlikely to be any kind of mounts. I dunno, possible coincidence I guess.

Edited March 26, 2012 by 1 Lucky Texan

[CNY_Dave]

Any time the car is jacked up, the car regards it as an excellent time to shift, break, crack, or drop some part or another.

[alaskanjer]

Bad Trans/motor mounts are more typical of the ea81s and possibly ea82s. The ea81s had tiny trans mounts and wore out easily and quickly, not to mention that they are all old and the cars were probably abused in 4WD at some point in their lives. A '98 Outback has more robust mounts. With 200k they may need replacing if it has never been done, but that is probably not your problem in this case.

 

OK, that makes sense. Now that I think about it, it was in the "older gen subarus" forum that I read that. And no, I didn't massage the boot at all, so I'll give that a go.

 

@grossgary and 1 Lucky Texan

 

Axle nut was torqued to 140 ft. lbs. (with a newish but budget oriented torque wrench) Haynes said 123-151 ft. lbs. so I figured I'd shoot for the middle in case the torque wrench is a little out of spec. This was done with no weight on the wheel.

 

Pin was installed on on the tranny side.

 

grossgary, thanks for the tip on rebooting. I already got rid of the one axle because I didn't realize the boot was torn until it started going "wacka wacka wacka" on tight left corners, and I assummed that once it starts making noise, it was too far gone. Next time I'll try and save it. (well, next time I'll try and prevent it...) I will definitely reboot the other side rather than toss it. Should I get OE Subaru boots? Do I need a special kind of grease?

 

The Empi axle I did install was for the 2001+ cars that need the tone ring. (I was careful to make sure it wasn't for the 2005+ cars when the axles got an inch or so longer.) However, I didn't remove the tone ring. It didn't seem to be in the way of anything, but I only checked with the car in the air. I'll check for any evidence that it is rubbing on something with suspension/steering movement.

 

And if massaging the inboard boot doesn't yield results, I think I'll also take your advice and get another Subaru axle from the salvage yard. They are a little bit more in my neighborhood ($50) plus boots etc. but it sounds like they are worth it. And if rebooting is as easy as replacing the axle, then it should be a snap.

[1 Lucky Texan]

OK, that makes sense. Now that I think about it, it was in the "older gen subarus" forum that I read that. And no, I didn't massage the boot at all, so I'll give that a go.

 

@grossgary and 1 Lucky Texan

 

Axle nut was torqued to 140 ft. lbs. (with a newish but budget oriented torque wrench) Haynes said 123-151 ft. lbs. so I figured I'd shoot for the middle in case the torque wrench is a little out of spec. This was done with no weight on the wheel.

 

Pin was installed on on the tranny side.

 

grossgary, thanks for the tip on rebooting. I already got rid of the one axle because I didn't realize the boot was torn until it started going "wacka wacka wacka" on tight left corners, and I assummed that once it starts making noise, it was too far gone. Next time I'll try and save it. (well, next time I'll try and prevent it...) I will definitely reboot the other side rather than toss it. Should I get OE Subaru boots? Do I need a special kind of grease?

 

The Empi axle I did install was for the 2001+ cars that need the tone ring. (I was careful to make sure it wasn't for the 2005+ cars when the axles got an inch or so longer.) However, I didn't remove the tone ring. It didn't seem to be in the way of anything, but I only checked with the car in the air. I'll check for any evidence that it is rubbing on something with suspension/steering movement.

 

And if massaging the inboard boot doesn't yield results, I think I'll also take your advice and get another Subaru axle from the salvage yard. They are a little bit more in my neighborhood ($50) plus boots etc. but it sounds like they are worth it. And if rebooting is as easy as replacing the axle, then it should be a snap.

 

 

If possible, move your other original axle to the other (EMPI) side. Reboot if you want. The wear forces will be on almost new surfaces. Try to get a junkyard axle and do the same - that is, get one from th eopposite side of where you intend to mount on your car and the bearings/balls will be running against less worn surfaces inside the joints.

 

sad to hear the EMPI might be bad. maybe I just lucked out on mine.

[alaskanjer]

Well, color me embarrassed.

 

I went to pull the other axle and re-boot it and discovered a lot more brake drag than there should have been. Also, the pads were just about gone on that side when the other side were still in great shape. I cracked the bleed screw to see if it a caliper problem or something else. It turned out that one of the brake caliper pistons was frozen. I swear on a stack of bibles that I never noticed the vibration until I put the Empi axle on, but it must have been there before because when I fixed the frozen caliper and installed new pads, the vibration totally went away. It wasn't the Empi axle after all.

 

I still need to re-boot that other axle. Any idea who MWE or Subaru gets boots from? Is one company's boot pretty much as good as another?

 

And thanks 1 lucky Texan, for the tip about switching sides, that's smart and I wouldn't have thought to do that.

[forester2002s]

Congrats at finding the problem and fixing it.

 

I wonder whether your brake rotors are warped a bit?

That would explain the vibration with the frozen calipers. In that situation, the brake pads are trying to follow the waviness of the rotors, and they transmit a vibration into the steering knuckle.

 

Whereas with free-moving calipers, the brake pads would be pushed back a bit by the movement of the rotor, and you wouldn't feel that vibration.

 

Just a thought.

[alaskanjer]

They (or maybe just the right one) might have been, but I replaced them so I don't know for sure. I think the vibration had something to do with brake getting hot. It would always show up the minute I hit highway speeds but only last 5 minutes or so.

 

The frozen piston was caused by water getting past the stretchy wrinkly dust seal (I don't know what it's called) but not the square cut O-ring. Of the four pistons on the front of the car, this only happened to one, and that one was the only one without silicone grease inside. So maybe (I'm definitely not an expert) when you rebuild calipers, it might be better to use silicone grease to lubricate the parts upon reassembly, rather than brake fluid.