Clutch pack issue- I think

[laseron]

Hello all,

My wife has a '97 Outback with 100,000 miles on it.

It had the common "binding in tight turns" problem a few months ago. I put the FWD fuse in, and the problem disappeared, so I had the transmission fluid and filter changed at the dealership. No more problem- for a while. Now, after driving for 10 - 15 minutes, there's a gradually increasing shudder coming from (I think) the transmission. That makes me suspect the clutch pack in the rear of the tranny, maybe brought on as it heats up. Am I on the right track?

I understand that the fuse activates the Duty C solenoid, so it doesn't seem to be the problem (I'd get a trouble code for that ). My concern is that the clutch pack was damaged during the torque binding. Any ideas?

Thanks, Ron

[splicesite]

Hello all,

My wife has a '97 Outback with 100,000 miles on it.

It had the common "binding in tight turns" problem a few months ago. I put the FWD fuse in, and the problem disappeared, so I had the transmission fluid and filter changed at the dealership. No more problem- for a while. Now, after driving for 10 - 15 minutes, there's a gradually increasing shudder coming from (I think) the transmission. That makes me suspect the clutch pack in the rear of the tranny, maybe brought on as it heats up. Am I on the right track?

I understand that the fuse activates the Duty C solenoid, so it doesn't seem to be the problem (I'd get a trouble code for that ). My concern is that the clutch pack was damaged during the torque binding. Any ideas?

Thanks, Ron

 

 

My personal (and costly) experience with the whole "torque binding" issue is that in many cases people spend hundreds or thousands on new differentials and solenoids and tranny work when the problem can actually be resolved by making sure all 4 tires are the EXACT same diameter. Even if the tires are all the same brand and same model, uneven wear between the tires on the front and rear axles (caused by replacing one axle of tires at a time) makes the subaru differentials crazy. I would like to suggest to anyone having this type of problem as a first step- simply rotate the rear tires to the front and the fronts to the rear and see if helps the problem (by reversing the difference in tire sizes between front and rear somehow it seems to make a difference). Of course, it may be a more severe problem, but this simple (and free) test warrants a try.

 

This actually solved my torque binding problem (which hadnt gone completely away even after replacing the center differential!!), only after talking to several different techs one finally said, "yeah its obviously your tires"....

 

It also seems that rotating your tires from front to rear can cause a partially damaged clutch pack to more-or-less function somewhat normally again, as the strain of the unevenly distributed torque is relieved (or reversed) from doing this.

[laseron]

Thanks for the input. Like many of us, I tend to look for complicated solutions to these things, when beginning with the simplest fix is always the best place to start. Ron

[Chef]

This is good advice regardless, but it seems to me that the problem still exists - the difference in circumference is still an issue, and therefore should still cause binding.

[splicesite]

This is good advice regardless, but it seems to me that the problem still exists - the difference in circumference is still an issue, and therefore should still cause binding.

 

 

Agreed. In my limited experience, having tires of ever-so-slightly different circumference on the front and rear (same size, different brand) did not cause binding immediately but rather gradually perhaps due to increasing wear in the differential. Binding was as classically described by everyone. Rotating the tires from from to back effectively reversed the way the imbalanced torque was distributed and provided short-term relief of the problem. I dont profess to understand the mechanism involved with the way the plates in the differential interact to cause this problem, but I imagined that by rotating the tires back-to-front the process of wear would begin again but in the opposite direction, if you understand my meaning. I dont know if this reasoning is valid. All I can say is that rotating the tires immediately resolved the problem until I was able to purchase 4 new identical tires (this was after I had already wasted $$$ on tranny work!!).

 

A couple years later I hit a curb and blew out one tire (right rear). I tried replacing just one axle of tires with an identical (but brand new and thus of slightly larger diameter) pair and the binding problem started immediately. I again rotated the new tires up to the front and put the old pair from the front on the back axle and the problem immediately ceased. Concerned that I would be causing another problem in the long term, I ended up just buying two more tires so all four are identical. My conclusion from all this is that the Subaru AWD system (at least on my 95 Legacy) necessitates always changing all 4 tires together to avoid torque bind problems.

 

Many Subaru mechanics will tell you this is plain fact, however I would guess that upwards of 90% of tire shops will replace one axle only with tires of a completely different brand without even a clue that this is potentially a huge problem. If you try to explain to them that even slight variances in circumference such as between different brands of the same size tire (or heaven forbid- differing wear on tires of the same make and model), they will look at you like you are crazy. Of course they wont try to stop you from buying a complete set of four though!