Torque binding question

Can a fifth generation 2012 Subaru Legacy 2.5l with CVT experience torque binding? I was told that vehicle with CVT are except from torque binding.

 

I have been chasing the solution to a noise and shudder when turning, I have replaced the belt, tensioner, power steering pump, idler pulley and flushed the power steering fluid but that did not help, I brought the vehicle to the dealer and mentioned the torque binding issue and they told me that since I have a CVT I don't have to worry about torque binding.

 

What do you guys think?

The binding was with the older Multi-plate clutch pack, the solenoids I think used to stick from old age or just not being used very often. The fix, was to do some figure 8s in a parking lot. But I believe the CVT is VTD so that shouldn't be an issue on them. But the figure 8s could still be fun!

Do all 4 of your tires have same tread depth?

Do all 4 of your tires have same tread depth?

 

No, and they are different brand, is that a big issue?

For Subarus, it is really important. The manufacturer wants all tires to have the same rolling circumference within pretty tight tolerances (1/4 inch). That's why it's important to use the same tires all around and keep them rotated on schedule.

 

http://www.subaruoutback.org/forums/66-problems-maintenance/30110-tire-circumference-spec-confirmed-subaru-techtips.html

No, and they are different brand, is that a big issue?

 

That is a very big issue! I hope for your sake it was shop that put them on and told you it would be ok.

Get 4 new same brand, same model, same size tires....IMMEDIATELY!!!!

What's the difference in tread allowed between tires? Isn't it no more 2/32nd's?

This cost me a center diff! 500$ part without counting my time to drop the trans and bla bla bla. Manual trans set up though, not cvt.

What's the difference in tread allowed between tires? Isn't it no more 2/32nd's?

The important measurement is the tire rolling circumference, so tread depth is derived from that, and depends on diameter of the tire. Figure somewhere between 1/32 and 2/32 for a 17-inch size tire.

 

If you wanted to be really meticulous you could measure the circumference of the tires on a lift using a measuring tape.

Yeah, I like the explanation in the link below. 1-2/32" might not sound like much, but it's the overall circumference of the tire that matters. It's much easier to use a tread depth gauge and measure 32nd's than it is to measure the circumference of a tire accurately, I've tried circumference, it's annoying to do.

 

Text and image below copied from the link below.

 

"It's been a long time since Subaru of America has posted anything official concerning the impact of tire circumference on the AWD system, so I thought I'd note that the December 2010 issue of TechTips has the following article which, once again, confirms the need for all four tires/wheels circumferences to be within 1/4 inch of each other.

 

Here is the text (also in the attachment)

 

"The Techline continues to receive calls from Technicians who have performed all types of unsuccessful repairs to transmissions with a “binding on turns” concern from the Customer. One of the first questions we will ask is whether or not the tire circumferences have been measured. All too often the answer is no. It is extremely important when diagnosing a transfer clutch-related concern, the tires must be one of the first variables you rule out. Remember, all 4 tires should be within approximately ¼" of each other in circumference when measured at the center of the tread. Otherwise, binding issues can result (or re-occur) due to the ratio imbalance caused by mis-matched tires. A quick keyword search on STIS of “Binding on Turns” will return a list of other bulletins and TIPS articles on this subject."

 

Odd size tires simulate tires slipping due to their different rotational speeds, and a slipping tire condition causes the AWD system to engage the clutch more fully (to help stop the slipping). If a car is driven with this condition when the tires in fact have good traction, the clutch will be forced to slip continuously, which will cause undue wear. The result could be mechanical damage that ultimately causes the clutch to remain engaged at all times (or not to work at all). The same can also happen to the center viscous coupling used in the manual transmissions.

 

The TechTips article deals with tire circumference when there might already have been a failure. What it does not say explicitly, but does imply, is that driving with tires with significantly different circumferences can damage the AWD system.

 

Different circumference tires turn at different speeds. Tires turning at different speeds appear to the AWD system as if they are slipping. The AWD system is designed to prevent this by engaging the AWD clutch in the automatic transmissions, or activating the center viscose coupling in the manual transmissions. If a car with different circumference tires is driven when the tires in fact have good traction, the clutch plates will be forced to continuously slip one against the other and in the case of the manual transmission, the viscous coupling will overheat. In both cases, the effect is undue wear and the potential for premature failure of the AWD system.

 

Some have mistakenly interpreted the measurement requirement to be the diameter or radius, whereas it's the circumference that counts.

 

A 1/4 inch difference in circumference in a typical 17 inch tire used on Subarus translates to between 1/32 and 2/32 of an inch difference in tread depth (or radius). It's not much. "

 

http://www.subaruoutback.org/forums/66-problems-maintenance/30110-tire-circumference-spec-confirmed-subaru-techtips.html