Tire Howl

[Buick350X]

Rear tires on our 00 Sub Forest howl louder n louder with speed, inflated right, running Yokohama® AVID Touring-S on the rear. I don't drive it that often so I never noticed when they were put on the rear. Annoying to sat the least.

[Suzam]

Oh no! Are you trying to tell us you are running mismatched tires?

[Buick350X]

Oh no! Are you trying to tell us you are running mismatched tires?

 

front to back makes no difference only side to side does.

[johnceggleston]

front to back makes no difference only side to side does.

 

i believe you are mistaken. my owners manual says that all tires should be within 1/4" circumference of each other.

 

i have also heard it said that the average of the fronts needs to match the average of the rears. but this is new to me and i'm not sure, but it is an interesting concept.

[Buick350X]

A 1/4 difference would mean bald tires.

 

all 4 are brand new 205/70/15 stock size, only reason they are different brand is by chance.

 

I tried 205s on my Buick wagon and didn't like them, ran to low in the front, so they came right off. so when the Sub needed tires we already had 2 new ones ready for it, but could not get 2 more of the same brand, so we picked up 2 Yoks for the rear.

 

That is not it.

 

But side to side you should never miss match brands of the same size, new or not.

 

front to back means nothing if they are new.

[johnceggleston]

But side to side you should never miss match brands of the same size, new or not.

 

front to back means nothing if they are new.

 

not on a90 - 99 awd subaru. yours may be 03 or so and it could be different, but i doubt it.

 

side to side you could, in theory, run a 13 and a 16 tire of completely different sizes and the open diff would not complain. it may not be optimum, but it would handle it.

 

but on an awd subaru, the center diff will take a beating if the front and rears are different sizes.

 

an if you think that all 205/70/15 tires are the same size i suggest you go measure a few. different brands will be have a different circumference even when the tires are the same size. and a 1/4 inch of circumference difference is not unheard. we are not talking diameter, which is about 26.3'' on a 205/70/15. we are takling the measure around the outside of the tire, which is in the 86.6'' range on a 205/70/15. 1/4" is ~0.2% of the starting point.

 

and then there is the wear factor, if the fronts are 40k tires and the rears are 80k tires they are going to wear at different rates and they will not be the same size in a year or two.

 

and in fact, on an awd subaru you are better off with one brand on one side of the car and the other brand on the other side of the car because the open diffs will allow that. the center diffs are more particular.

 

but don't take my word for it, read your owners manual.

Edited November 21, 2010 by johnceggleston

[idosubaru]

i've never heard of solutions to noisy tires. wonder what makes one noisy anyway.

 

your year forester is notorious for failed wheel bearings, make sure it's not that. Subaru has an updated bearing design to replace them with.

 

return, get a credit, etc? check the reviews at tirerack.com or similar tire sites? might be a common issue or you might be able to check next time before you buy.

 

1/4" does not make a tire bald - it's circumference difference that the Subaru manual talks about - not diameter.

 

same size tires can be quite different in actual size. this won't be causing this issue though.

 

side to side you could, in theory, run a 13 and a 16 tire of completely different sizes and the open diff would not complain.

if it's not an S model it doesn't matter side to side, it's just an open diff in the front and rear. you can google or look it up elsewhere if you like on how an open diff works.

 

if front to back didn't matter then technically Subaru's would never need to have tires rotated since they don't tend to wear one side faster than the other due to AWD (depending on driving style ). but that's not the case and does cause damage.

[StructEngineer]

My Yokohama Envigors also howl. It may be a yokohama thing.

[brus brother]

My Yokohama Envigors also howl. It may be a yokohama thing.

drats, I just got a set of envigors delivered yesterday but haven't installed them yet. i'll keep you posted.

Edited November 22, 2010 by brus brother

[Fairtax4me]

front to back makes no difference only side to side does.

Wheres my news paper?

 

Front to back makes the difference of your center transfer unit wearing out. Larger tires on one axle (front vs rear) will create a difference in driveshaft speeds, which causes the transfer unit clutches to slip constantly when the vehicle is in motion.

Side to side will make a change in half axle speeds which will be balanced out by the front and rear differentials. This is still not good for the differentials, arguably it can be worse repair-wise, since a worn out spider gear shaft in the diff can lead to failure in the form of chunks (the big kind) dropping out from under the car. Then you get stranded.

 

Either way, with an AWD vehicle of any kind (not just Subaru), you NEED 4 tires, one of the same size, type, and wear, on each corner of the car to avoid wear and/or damage to the drivetrain.

 

edit:

1/4" difference in circumference on a tire with an overall diameter of 26.4" (size of a 205/70/15 Yokohama Avid Touring S, according to Tire Rack) would be about 2.8mm overall diameter, 1.4mm tread depth.

Edited November 22, 2010 by Fairtax4me

[StructEngineer]

drats, I just got a set of envigors delivered yesterday but haven't installed them yet. i'll keep you posted.

 

FWIW I have the V rated version and the noise got worse as I upped the air pressures.

 

I think yokohama's in general are more hollow sounding because of softer sidewalls so any tread noise is amplified.

[johnceggleston]

1/4" difference in circumference on a tire with an overall diameter of 26.4" (size of a 205/70/15 Yokohama Avid Touring S, according to Tire Rack) would be about 2.8mm overall diameter, 1.4mm tread depth.

 

1.4mm is less than 2/32s.

[mdjdc]

From the original posters second post, I don't think he is going to listen. Personally, I learned from an Outback that I bought from a friend. He was in the habit of only changing two tires at a time (front or back) and within a year I had a bad viscous coupling and I had to replace the trans. It just isn't worth the trouble to save a little bit now and have a much bigger bill down the road.

 

Just my 2 cents

[edrach]

From the original posters second post, I don't think he is going to listen. Personally, I learned from an Outback that I bought from a friend. He was in the habit of only changing two tires at a time (front or back) and within a year I had a bad viscous coupling and I had to replace the trans. It just isn't worth the trouble to save a little bit now and have a much bigger bill down the road.

 

Just my 2 cents

Center diff cost is around $600 just for the parts. Add to that the cost of replacement. Been there, done that.

[mdjdc]

And the two extra tires are about 150. Just not worth the trouble. Espescially if the bind comes on in the winter. It sucks to loose traction on the snow in a turn.

[Fairtax4me]

And the two extra tires are about 150. Just not worth the trouble. Espescially if the bind comes on in the winter. It sucks to loose traction on the snow in a turn.

 

Depending on what kind of tires you buy, they might be 150 a piece.

[brus brother]

drats, I just got a set of envigors delivered yesterday but haven't installed them yet. i'll keep you posted.

 

FWIW I have the V rated version and the noise got worse as I upped the air pressures.

 

I think yokohama's in general are more hollow sounding because of softer sidewalls so any tread noise is amplified.

 

OK I'll run mine flat. Problem solved!

Seriously, how were they when you used the recommended tire pressure for the car as posted on the door jamb?

[mdjdc]

Even at 150 a piece, that is still a far cry from 600 for the viscous coupling and the labor to install it, or the parts and labor to fix the auto trans when it starts binding up. That can also be a very dangerous proposition when the tranny binds in bad weather and you lose traction.

 

 

 

 

 

Depending on what kind of tires you buy, they might be 150 a piece.

[StructEngineer]

When I ran the envigors at the pressures on the door they made the noise but it was practically unnoticeable. My biggest issue at stock pressure was that they were squirmy. I couldn't stand driving them on the interstate because they needed constant correction. 1000 mi into my roadtrip I had to bump up the pressures.

 

I feel like we have two threads going here, geesh.

[brus brother]

When I ran the envigors at the pressures on the door they made the noise but it was practically unnoticeable. My biggest issue at stock pressure was that they were squirmy. I couldn't stand driving them on the interstate because they needed constant correction. 1000 mi into my roadtrip I had to bump up the pressures.

 

I feel like we have two threads going here, geesh.

yeah you're right. We now have howling tires as well as squirmy tires:lol:

[Suba9792]

its not the tires, its the rear wheel bearings getting ready to explode! it just happened to my friends forester, they are notorious for bearing failure. Get it done ASAP.

[mdjdc]

For what it is worht, I have BF Goodrich Tratctio TA's on my 99 forester and they do howl someon the highway. Worse on some types of pavement, bt they have a more agressive tread pattern and that is what I wanted. Overall I like them except for the fact that they are a rotational tire. Didn't know that when I bought them. Got them for about 100 bucks off a car that was being parted out and they were brand new.

[Fuzpile]

Re the measuring; My legacy had different brand tires F/R same basic size yet I was concerned and measured them with a BFC (caliper) to compare the outside diameter. It was about .125" (1/8) difference. I just measured with a tape measure across the tire from inner rim lip to outer lip (very straight) and see 1/8" difference that way too.

[Fuzpile]

Re my measurements. The problem with this is that would mean twice that difference approaching the magic number. I need a set of 4 185-195x70x14.

[Fuzpile]

I can edit this all out in a few days. I don't intend to distract from the thread. Only that there are ways suggested to measure the effective working diameter and that includes this cross section.