Cause of burning smell from R front tire well only???

[mountainwalker]

Hi All, sincerely appreciate your help narrowing down the cause of this. The USMB community has been a fantastic help, even in choosing the Subie we bought.

 

Friday after a 45 minute highway ride in our 2003 Subaru Outback 3L H6 VDC I noticed a burnt smell which smelled much stronger than the typical hot tires. When I checked around and under the car, I traced the smell to the front right tire/tire well. I could not find any evidence the tire was chafing against anything, or any evidence of any fluid leaking in the tire well or in the engine block on that side of the tire. The smell is stronger and more pungent than the typical hot tire smell.

 

Would could the source be? Car is in great shape, we have a great mechanic - honest, sharp and a good value, but before doing the rounds of mechanic, tire rotation place and alignment place (all 3 different locations), would be nice to be able to narrow it down.

 

Some things I've thought of:

 

1) Tire alignment issue (though I had the tires aligned about a year ago - probably a good idea to do again now - manufacture says it's unnecessary to do frequently but on an AWD vehicle I think it should be done once every 6 mo. to 1 year).

 

2) Tire rotation - I'm a little past due but not much, but don't understand why the R tire alone would act up

 

3) Leaking fluid that I'm not able to see which is falling on a hot part in the right side of the engine block close to that tire

 

4) Problem with brake fluid and brake pads causing the brake bads to close up much harder on the right front wheel

 

5) brake fluid leaking near the brake pads in the right front tire well

[MilesFox]

problems 1,2, and 4 would be similar to wheel bearing symptoms

[Fairtax4me]

Stuck brake caliper would be my guess. The slide pins are probably rusted so the caliper can not move away from the rotor. Pretty common problem.

 

Other possibilities:

The caliper piston is jammed.

The rubber brake hose has deteriorated and has blocked the return of fluid from the caliper back into the line.

 

edit: also what he said^

Edited May 9, 2011 by Fairtax4me

[mountainwalker]

Thanks MilesFox and Fairtax4me, really appreciate it. Fairtax4me, looked it up, sounds like it could definitely be causing the problem. Is it expensive to fix? If the part has to be replaced, is it an expensive part?

[mountainwalker]

Any detail you can provide? Really appreciate it.

[mountainwalker]

Member of another car forum also suggested that it could be the CV boot (Constant Velocity Boot): "If it splits it slings grease onto the exhaust. Which smells awesome. And the passenger side is the more common side to fail."

[Fairtax4me]

That depends on exactly what the problem is. If it's a wheel bearing, probably gonna want to take it to a dealer or at the very least a competent Subaru repair shop. The bearing itself is not expensive but needs to be pressed out of the hub and a new one pressed in. This also has to be done with a special tool to support the hub to prevent it from being deformed.

 

Brake issue. You need to remove the caliper and try to move the slide pins. They should move easily. If either feels stiff or doesn't move at all they are contributing to the problem if not the main cause. Brake caliper grease, new pins, new dust boots if the old ones are ripped, should be good to go.

[rverdoold]

I have ruined a set of brake pads within 10k miles because the slide pin was stuck AND the brake piston was not going back anymore (driver side front).

So now at every oil change I take the brake pads out and check the slide pins. It is rather easy:

 

 

1. Remove the wheel and screw 2 lug nuts back to keep the disc positioned.
   
2. Undo the 14 mm bolt at the bottom-back side of the caliper house and fold the caliper up (a little gentle hit with a teflon hammer might be required).
   
3. Remove the brake pads on both sides and lower the caliper and mount back the 14 mm bolt.
   
4. Now you should be able to move the caliper back and forward easily (slide pin operation).
   

If not then one of the slide pins is stuck, undo the lower 14 mm bolt and pull the slide pin out with a bit of care at the dustcover which is just hooked on the edge. You really have to clean the slidepin hole very good with a stembrush (to clean bottles and pipes). And so for the top one you can leave the caliper hanging on the spring of the car.

The lower slide pin had some sort of rubber endcap, I removed this one because i think it was the cause of the problem. I used special brake lubricant to put them back in. No copper grease here!!!

 

Because this was not all of my problems i popped the brake piston out as well and honed the cylinder and cleaned the rust from the piston, regreased and put it back together. (before you take the brake piston out check if the bleeding valve opens) I guess you can also get re-manufactured calipers but here that is rather rare (holland).

[94Loyale]

I'm putting my chips on an axle boot.

[nipper]

Sicking brake caliper.

grease on a cat exhaust from a broken boot

oil leak.

[idosubaru]

before doing the rounds of mechanic, tire rotation place and alignment place (all 3 different locations), would be nice to be able to narrow it down.

the mechanic is who you'll be going to for this. this is not an alignment or tire issue.

 

i doubt it's leaking brake fluid if you don't see fluid on the ground or notice any other symptoms.

 

they've covered the possible causes. a dragging brake pad would get my first vote. the calipers can stick or the pads can hang up in the brake caliper clips if they're corroded, both cause the pad to ride on the rotor when it shouldn't.

 

if it's just the clips, then replace the pads and clips. some pads come with new clips, like Adaptive One Ceramic pads from NAPA.

 

if it's the caliper then it depends why/how it's sticking.

 

in general subaru calipers don't fail very often at all...though rust gets some of them - most 1980's subaru's still have the original calipers on them. that being the case, buying a new caliper is pretty much a waste of money. i'd replace with a used caliper or rebuild it - Subaru calipers are simple to rebuild. last rebuild kit i bought was less than $4 for a legacy...funny since any shop would have charged that friend hundreds for a new caliper. but few mechanics will rebuild calipers any more.

[rverdoold]

Subaru calipers are simple to rebuild. last rebuild kit i bought was less than $4 for a legacy...funny since any shop would have charged that friend hundreds for a new caliper. but few mechanics will rebuild calipers any more.

 

WOWOW that is unfair, here they charge 20 euros then you get all rubber parts a rebuild cost 200 euros which is insane i agree!!

I really should make a shopping list for next time I cross the ocean.

[mountainwalker]

Thank you for the great advice. It was the CV boot - it had been slashed open by road debris spraying grease on the exhaust. It was actually cheaper to put a new axle on the car rather than a new boot as a new axle assembly with labor was cheaper than a new boot assembly + the higher labor to replace it.

[Fairtax4me]

It often is cheaper to replace an axle than to repair one. I still choose the repair option when the boots are just split. After market axles tend to be poor quality and often cause way more headache than they're worth down the road. They wear out quickly, cause vibration/shaking, then the cheap boots on them split and you get to replace them all over again.

[mountainwalker]

Wish I knew that beforehand. Though the difference was fairly high - well over $100 more for repair. Whole axle replacement including labor cost only $190 (and would have been double to triple at dealer).

[mountainwalker]

Hope you all had a nice holiday season. Best wishes for a healthy, happy, peaceful, fun, successful and smooth-driving 2012.

 

About several weeks ago my wife and I started to hear a low but noticeable wrr-wrr-wrr-wrr-wrr sound when driving on curves over 25-30 mph when curving right and left, uphill or downhill, powered or unpowered, and it seemed to be coming from the front of the car (wheels/axles/steering). Could this be related to the replacement of the axle after the CV boot blew?

We've got a 2003 3.0 L H6 VDC Outback 2003 in excellent condition, at 105,466 miles, and about to perform the 105K inspection and servicing, which is a minor servicing. Brake pads were replaced only a few months ago, the axle was replaced a few months ago when the CV boot was blown open, and the wheels were aligned a little before we started hearing the whirring noise on curves.

 

Tried looking it up and found references to a noise like this possibly being caused by:

 

- Wheel bearings CV joint / axle

-Grinding on front wheel caused by either a bad or loose wheel bearing or worn out brakes

-Tire rubbing against the inner fender

-Backer plate on the brakes rubbing the rotor (brake pad clearance is close and sometimes turning will result in a light scraping of the brakes against the rotor)

-Check the level of fluid in the power steering

-Steering column

 

Any ideas?

[Olnick]

You never mentioned what your original axle was replaced with. If it was a "cheap" aftermarket axle that just might be the problem.

[mountainwalker]

It was an aftermarket axle. Unfortunately I didn't see the warning about aftermarket axles until AFTER I came back from the garage. Our independent garage is excellent, and while the mechanic works on Subies, they are not Subaru specialists. They are however a much better value than the Subaru dealers, do good work and provide good advice. The mechanic explained that replacing the whole axle would be cheaper by over $100 than replacing just the CV boot, and not knowing anything more about it I went for the seemingly better value.

 

The service manager at the best Subaru dealer near me quoted the cost of a new Subaru axle at $410 and a remanufactured one at $200 (and I bet that's without labor).

 

1) Would you replace the aftermarket axle with a remanunfactured or new axle? Will a reman be just as good? It will probably be no worse than the original axles on my other 3 wheels.

 

2) Will a remanufactured Subaru axle be any cheaper through our independent garage, and what do you think would be a fair price for the labor on the axle?

[mountainwalker]

At Subaruoutback.org forums, 1 Lucky Texan said:

 

"I have had no problem with the EMPI axle I put on my Outback. So far, I'd have no problem getting another one. (they are new and properly heatreated - purchase from Rockauto or Amazon, probably other places)

 

Knowing what I know now, I would also consider getting an MWE (they are well-rebuilt original Subaru axles, purchase through CCRengines.com w'ever)

 

If I was a major DIY-er, I'd rebuild my own axle. You can find instructions for that on-line.

 

I would avoid any other rebuilt axles I think.

 

hard to speak to the money side of your question. Axles can vary in price but should be $90 +/-20-30 $ I think. Sometimes free shipping.

 

I might not be able to sleep at night if I charged someone more than an hour - 90 minutes of labor. having done this once, I bet I could change one in 45 minutes.

 

A GOOD indie mech should have no problem with this."

 

Anyone have any experience with the

[Olnick]

1) Would you replace the aftermarket axle with a remanunfactured or new axle?

 

Try a search here on USMB--you'll find that many of us recommend MWE's rebuilt genuine Subaru axles. Good quality at a reasonable price. And Marshall Wolf, the owner, is a straight shooter--I can vouch for that personally.

[mountainwalker]

Where can you get MWE rebuilt Subaru axles? Can our indie garage order them directly?

 

Can't help but laugh or cry thinking that we could be buying back our own rebuilt original axle LOL.

[Olnick]

I think you'd be better off handling it directly--there are shipping costs and a core deposit to deal with. Just call Marshall directly, here's a link:

 

http://www.ccrengines.com/mwe/

[mountainwalker]

Spoke with Marashall, was very helpful, thinks whirring sound is from a bearing issue, recommended I go someplace where I can bank right and bank left to full extent of wheel turn range and see if sound louder on one side (so far during driving have heard same sound turning right and left, but haven't come close to edge of steering range). Anyway if anyone interested, his axles for my model year run $95, with $35 shipping (I believe $95 for all model years 2000 and up).

[jarl]

Just a quick note: on my '99 OBW with stuck rear brakes you could hear some grinding when turning in one direction. I don't know what could be flexing, though.

 

Also, if you replaced only one of the axles before, try to take a look at the other one. The boot may be in so-so shape too

[mountainwalker]

So the wrr-wrr-wrr-wrr-wrr sound my wife and I heard when driving on curves over 25-30 mph when curving right and left, uphill or downhill, powered or unpowered, which seemed to be coming from the front of the car, was caused by a bad wheel bearing, apparently the Left Front. It could be entirely unrelated, but it happened not long after replacing the axle after the R Front CV boot blew open after it was hit hard by some road debris on the highway + wheels aligned.

 

This is for a 2003 3.0 L H6 VDC Outback 2003 in excellent condition, at 106K miles.

 

Our very good independent garage mechanic recommended about a month or two ago to drive on it a little longer, so that we could be 100% sure which wheel the noise is coming from. Seems clear right now it's the Left Front. He said it wouldn't cause any further harm driving on it longer. It is getting progressively louder to the point where we can hear extra noise in the background even when driving straight.

 

Two questions:

 

1) A service rep at our local Subaru dealer claimed driving on the bad bearing longer could cause damage to the hub and housing, resulting in a more costly repair. True or not? Note that however many parts need to be replaced or whatever the labor, the dealer costs 2x as much as our very capable independent garage.

 

2) Does a $585 estimate by the independent garage for parts and labor for replacing the front hub and wheel bearings sound right to you? The dealer quoted $550 parts and labor for just the bearing replacement; an additional $176 for the hub parts if those are necessary, and an additional $294 labor plus more $$$ in parts for the housing if that's necessary.