I can't find my initial post on this problem and this weeks shutdown seems to have lost the conversation so I'm starting a new thread. 04 Runner, little over 100k miles. Right rear wheel well area has burning rubber smell after 30 minute trip up to ski area. Upon board advice I changed the wheel bearing, new axle oil seal as well. Smell persists. Brakes feel just barely warm to the touch. No sign of leakage, nothing dripping on exhaust. What's really odd is the return trip home downhill has no evidence of smell. The last 5 miles up are 40mph uphill vs 65mph flat coming home with a mile of 25mph at the end. I'm out of ideas. I adjusted parking brake as part of the bearing job. Main brake pads seem fine, nothing unusual.

Not sure what your issue could be but here's a link to your initial topic on your issue.

Burning smell

Reading your initial topic and the few replies I wouldn't have jump on changing the wheel bearing from just what was posted, but at least you know the bearing is now indeed not an issue, but now your out some dollars and back to square one.

Did you do the work yourself or pay a mechanic to do it?

If you paid a mechanic to do it he should of been able to tell if the bearing was indeed bad before doing the work and I wouldn't trust him to do more work if he couldn't tell if it was bad or he just wanted to make the money and did it anyways!

If you did the work and can't tell if a bearing is bad before changing it I would recommend you at least take it to a qualified mechanic and let him at least find the issue.

My guess and it's only a guess is that your transmission "maybe" overheating when going up hill at only 40 MPH and the torque converter is unable to "lock up" which will make the transmission get much hotter and overheat, you never stated if you have a V6 or a V8, if a V6 it usually doesn't have the extra transmission cooler, the extra cooler only came stock on most V8s, the extra trans. cooler will help keep the transmission much cooler but it can still overheat if the torque converter can't lockup, but I would suggest trying the next time you're going up those hills try downshifting to the next lower gear which may help the torque converter lockup and it will not get as hot, if you have the V8 that would be 4th gear, if you have the V6 then it would be 3rd gear since you say you have a 2004 model.

That all being said I would also recommend getting one of the many ODB dongles and download an app such as Torque Pro or other apps that will let you monitor the transmission temperature and well as many other features they offer, also if you have never changed out all of the transmission fluid for new fluid I would recommend doing so especially if the transmission has indeed overheated which will greatly degrade the fluid, even if the transmission hasn't overheated it would still be a good idea to change the fluid, not just a drain and fill which only changes out 1/4 of the fluid do a complete change of the fluid.

Ok, yea I did the work myself. The old bearing seemed ok to me but I went ahead. Not big $. It's a V6. I have plenty of OBD tools and Techstream so I'll try monitoring transmission temps. I changed all fluids including a tranny flush when I got the car a year ago. If it was tranny why is the smell only at the right rear wheel?

Not sure but as I stated it's only a guess, but I based my guess on the fact it doesn't do it going back downhill where the torque converter is most likely locking up as it should, so monitoring the temperature driving the route as you normally do and also trying the downshifting and also monitor and see if the problem persists would be my next step, if no change then look elsewhere for the cause before throwing any more money at it.

Glad you did the work yourself and not out of pocket a lot on the bearing swap!

Yea, I live in a place with a small collection of very expensive shops so I pretty much diy everything. Sometimes it cost you $ due to mistaken diag. but it's part of the game. I'm going up tomorrow am so I'll check temps then. thanks

I'm interested in this. I've recently developed a similar smell on my V8 and can't quite place what's going on. Fluid levels aren't going down, and it doesn't quite smell like oil or coolant. Mostly strong in the right rear as well.

I live in the mountains of Colorado. And anytime I go up a pass I have the same smell coming from the passenger rear wheel. Did some research found its a common issue others report it just going away. Also my buddy has a brand new 5th gen and it makes the same smell. So after seeing that I quit caring about it.

Was it snowy on the trip to the ski place? Maybe just the spinning of the tire in the snow causing the rubber smell?

Its a common issue with the 4th Gen and 5th Gen. Possible issue could be its coming from the rubber hangers for the exhaust/muffler. I have over 253k miles on my 03 and I still get the burning rubber smell now and then.

Sounds like something to learn to ignore. That's good news.

I had a similar issue on my V8. Would smell like slight rubber/oil burn smell in the garage after my daily commute. Would get worse in the winter it seemed.

Discovered my valve cover seals were worn and building up residual oil on the lower block. Replaced both valve cover seals and the smell has greatly reduced. If I stick my nose to the front grill I can still smell it somewhat.

Not sure If this is the same issue, but this helped in my case.

Same smell on my 07. I gave up trying to find it a few years ago, the exhaust hanger is an interesting idea. Maybe grease from the slip yoke flinging on the exhaust?
It hasn't fallen apart or caught fire so i moved on.

Check for a sound deadening material above your exhaust. I had parts of mine fall on the exhaust and start to burn. Smelled of burnt rubber or oil.
-mike