Jump to content
Ultimate Subaru Message Board
Guest intrigueing

My AWD Torque Bind Problem - Solved!!!!!!!!

Recommended Posts

Guest intrigueing

Well it is fixed and here's the lowdown:

 

I conducted a controlled "study" to get the best results to report to the USMB on what worked for this problem. Here is what I did.

 

1) Checked all tire pressures 32PSI all around.

2) Drove car to get real familiar with torque bind situation. Every sharp turn left or right got 3-4 pulses of torque bind, steering wheel need not be "pinned" one way to get the bind however it was worse the sharper the turn. Turns to the left seem to be worse.

3) Changed rear Diff fluid with 80W90. Magnet was covered with black gunk - enough to make a large paper towel quite black. The top fill plug even had black on it, even though it is not magnetic.

4) Drove car, Noticably smoother and quieter straight line. Torque bind improved slightly, binds 1-2 pulses and only when steering wheel is pinned.

5) Changed Front Diff Fluid - Same Fluid. Not too much gunk on the magnet.

6) Drove car, torque bind 85% better mainly only doing it to the left, almost happy leaving it at that, then I remember End wrench article saying to measure tire diameter. My tires have dry cracking and the rears are noticably more worn than the fronts. All tires same brand (Bridgestone) and pressure is the same.

7) Jacked up car and measured tires, front to back passanger side was off almost 3/8 of an inch!!!!! Ok gonna get new tires, I kinda need them anyway. Then I remember someone on the board saying they filled their tires to 35 psi and their torque bind went away. Get out the compressor put the tires to 35 psi.

8) Drive the car and it is perfect and I mean Purrrrrfect! No bind at all, I could not get it to bind, ever!

 

Conclusions:

1) Check tire diameter before doing any trans work for torque bind.

2) Rotate your tires, rotate your tires, rotate your tires! I think I'm sold on the 5K interval now. And never mismatch brands, or types.

3) Change your diff fluid, it is easy, cheap and does have some impact on torque bind. My car is also way smoother than it was before.

Share this post


Link to post
Share on other sites
Guest newsooby

Wow!! Nice job! A very careful, scientific approach. And it sounds like your patience has saved you a few $$ too.

 

I wonder how many people have had mechanical work done to correct this "problem" when the true solution is as you described?!

 

Thanks for the top-notch analysis. Sounds like the first step to a potentially complex problem like this is to: stop, take a deep breath, and...think it through.

 

I love the info I get from this message board!!

Share this post


Link to post
Share on other sites

Yes the tires are always the first thing to check when this problem occures.

 

 

But over inflating a dry rotted tire is NOT a fix!

Share this post


Link to post
Share on other sites
Well it is fixed and here's the lowdown:

 

I conducted a controlled "study" to get the best results to report to the USMB on what worked for this problem. Here is what I did.

 

1) Checked all tire pressures 32PSI all around.

2) Drove car to get real familiar with torque bind situation. Every sharp turn left or right got 3-4 pulses of torque bind, steering wheel need not be "pinned" one way to get the bind however it was worse the sharper the turn. Turns to the left seem to be worse.

3) Changed rear Diff fluid with 80W90. Magnet was covered with black gunk - enough to make a large paper towel quite black. The top fill plug even had black on it, even though it is not magnetic.

4) Drove car, Noticably smoother and quieter straight line. Torque bind improved slightly, binds 1-2 pulses and only when steering wheel is pinned.

5) Changed Front Diff Fluid - Same Fluid. Not too much gunk on the magnet.

6) Drove car, torque bind 85% better mainly only doing it to the left, almost happy leaving it at that, then I remember End wrench article saying to measure tire diameter. My tires have dry cracking and the rears are noticably more worn than the fronts. All tires same brand (Bridgestone) and pressure is the same.

7) Jacked up car and measured tires, front to back passanger side was off almost 3/8 of an inch!!!!! Ok gonna get new tires, I kinda need them anyway. Then I remember someone on the board saying they filled their tires to 35 psi and their torque bind went away. Get out the compressor put the tires to 35 psi.

8) Drive the car and it is perfect and I mean Purrrrrfect! No bind at all, I could not get it to bind, ever!

 

Conclusions:

1) Check tire diameter before doing any trans work for torque bind.

2) Rotate your tires, rotate your tires, rotate your tires! I think I'm sold on the 5K interval now. And never mismatch brands, or types.

3) Change your diff fluid, it is easy, cheap and does have some impact on torque bind. My car is also way smoother than it was before.

 

 

I assume you didn't get any trouble codes from the TCU? It sounds like your TB was caused by a mechanical problem, right?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×