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torque bind and the FWD fuse


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17 replies to this topic

#1 bgambino

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Posted 21 April 2014 - 06:22 AM

So I recently bought a 95 legacy 4dr sedan with 2.2 and TB

I would like to find 2 matching tires as fronts are more worn....but the exact toyo model is not in production anymore and

I am not finding any leftovers anywhere yet--(Toyo Spectrum 185/70/14 in case anyone has free time and wants to search LOL)

 

I have to do the 3 flushes also

 

My question is:

Am I doing harm to the Duty C by using the FWD fuse all the time?

If so, I have to pull the rear shaft instead right?

 

It went completely away by putting the fuse in

 

If all easy attempts do not sure it......what will I need to do? Get the rear part of tranny off and have it rebuilt??



#2 mikec03

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Posted 21 April 2014 - 07:24 AM

I drove a 95 for at least 3 years with the fuse in, because I had torque bind.  I would take the fuse out when it snowed.  I didn't have any problem.  Of courses, the manual says not to do it.

 

Some people say that they eliminated the torque bind by replacing the fluid [3 drain and fills].  It didn't do any good with mine. 



#3 johnceggleston

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Posted 21 April 2014 - 07:51 AM

the duty C is an electrical part that is designed to switch on and off multiple times each minute.

will leaving it on all the time hurt it? possibly.

but it all depends on the age and condition of the solenoid.

 

you have mentioned 2 things that will cause torque bind,

dirty trans fluid and mismatched tires.

both of these are easier to fix than the duty c.

and both are cheaper if you are paying for labor.

 

tires need to be within 1/4 inch circumference,

buy a 10 ft steel measuring tape and measure your tires.

then you will have a target to shoot for.

 

if you do find tires the right size,

\you will need to keep an eye on the wear,

so they stay within spec.

rotate accordingly.

 

or pull the drive shaft and drive FWD.



#4 bgambino

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Posted 21 April 2014 - 09:53 AM

I was thinking of the same thing....pulling the fuse when it snows (assuming I can't do an easy fix)

 

Gary

I thought that if putting the fuse IN solves the torque bind.....that the duty C was ok....

If its not the tires or the fluid....a duty c is better than some kind of rear tranny rebuild

 

The one problem with your tape measure thing is this

the 2 front times are mounted

If I were to look for another set of tires with the same circumference(for the back)....they would need to be mounted and inflated to accurately compare

 

or conversely,,,,,I would need to break the bead on the good tires...take a measurement,,,,,,and shop for a new set of tires with the same

 

I don't want to buy 4 tires if I can get away with 2

 

Anyone ever go thru this exercise?

Is it possible to actually find the circumference of differing tire models online (I am doubting it)

thanks all



#5 johnceggleston

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Posted 21 April 2014 - 10:14 AM

correct me if im wrong,

 

the rubber and steel in a tire are not going to let the circumfrence change a lot .

an under inflated tire can be smaller since the tire can flex in toward the center.

but i do not think an over inflated tire is going to balloon up to a larger size.

 

i'm sure there is some variation,

but if you are looking to avoid buying 4 tires,

this is what you have to work with.

 

and it is better than not measuring anything.

 

or buy 4 used tires all the same.

or buy any two tires you want and mount one on the front and one on the rear.

done.


Edited by johnceggleston, 21 April 2014 - 10:17 AM.


#6 grossgary

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Posted 21 April 2014 - 12:31 PM

So I recently bought a 95 legacy 4dr sedan with 2.2 and TB

I would like to find 2 matching tires as fronts are more worn....but the exact toyo model is not in production anymore

 

matching exact model or even brand is unnecessary.  get the right size and you're golden.

 

1.  get your tires close

2.  change the fluid and see if it goes away - if the FWD fuse works then the clutches may free up with some fluid changes and matching tires

 

you can run it indefinitely with the FWD fuse, don't worry about it.

 

if the torque bind doesn't go away a simple fix would be to install a switch for the FWD fuse - one position of the switch would be FWD - the other position would be "locked" 4WD.

 

or replace the clutches in the rear extension housing to get it back to nominal operation.



#7 1 Lucky Texan

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Posted 21 April 2014 - 12:44 PM

correct me if im wrong,
 
the rubber and steel in a tire are not going to let the circumfrence change a lot .
an under inflated tire can be smaller since the tire can flex in toward the center.
but i do not think an over inflated tire is going to balloon up to a larger size.
 
i'm sure there is some variation,
but if you are looking to avoid buying 4 tires,
this is what you have to work with.

I've been thru these theoretical discussions before. I'm in the camp that the actual radius (distance from hub to ground) in use when the car is rolling is what matters. If that's true, inflation values could be manipulated (within limits) to eliminate TB. Of course, SAFETY and handling could be compromised.

sometimes, you can find used tires on ebay, or have a tire 'shaved' at a performance shop. I would never have 2 tires shaved. The money spent and value lost in tread wear combo is too much. better to get 4 new tires.

 
HOWEVER, as mentioned,(on a car with open diffs front and rear) with 2 worn tires that match EACH OTHER, 2 MATCHING new tires can be put on opposite corners and everything should be fine even if new is different from old.

Edited by 1 Lucky Texan, 23 April 2014 - 01:33 PM.


#8 CNY_Dave

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Posted 21 April 2014 - 08:22 PM

Flat smooth parking lot.

 

Chalk where each tire meets the ground.

 

Drive straight so one tire's mark kisses the ground 10 times.

 

within 1/4 inch circumference = furthest 'forwards' mark closer than 2.5 inches from (measuring along the surface of the tire) where the furthest 'rearwards' mark is.



#9 bgambino

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Posted 23 April 2014 - 01:12 PM

hmmm...interesting subject

Perhaps I'll get two new tires and be done with it

then do the fluid changes

 

I'm intrigued by the switch idea gary

What confuses me though is.....why would it be "locked" 4wd

Isnt the switch basically taking the place of installing and removing the fuse all the time?

 

Another question

If the duty C burns out....is 4wd then impossible?



#10 grossgary

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Posted 23 April 2014 - 01:25 PM

I'm intrigued by the switch idea gary

What confuses me though is.....why would it be "locked" 4wd

Isnt the switch basically taking the place of installing and removing the fuse all the time?

 

If you have:
A.  nominally torque bind (normal driving conditions)

and
B.  FWD with the fuse installed

 

then wiring in a switch would allow you to flip between A (torque bind which is "locked" 4WD) and B - FWD.

 

The Duty C solenoid is not going to burn out.  many people have driven for years with it and no one has ever had one burn out.  maybe you'll get unlikely but highly doubtful.  If it does "burn out" and you end up "locked" in 4WD and the FWD fuse doesn't work - then simply remove the rear half of the drive shaft and you've got FWD.  No big deal.



#11 bgambino

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Posted 23 April 2014 - 02:04 PM

Thanks Gary

 

When you said "locked" I was thinking of the old pickups and actually locking the differentials

 

I really like the switch

whats involved?



#12 CNY_Dave

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Posted 25 April 2014 - 07:55 PM

There are threads on it, but you use a stout double-throw switch to 'cut' the solenoid wire and send the signal from the TCU through a resistor to keep the TCU from throwing a code and lighting the ATF Temp light.



#13 grossgary

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Posted 26 April 2014 - 11:00 PM

Typically you install a switch with simply two positions, it's been a couple years since I wired one but something like this, I've always used a DPDT switch (double pole, double throw):

 

Position 1. "Locked" 4WD

Position 2.  normal AWD

 

Position 1.  nothing connected here - in this position, the wire isn't connected since it's not in Position 2 below. so power is cut to Duty C, "locking" it in 4WD.

Position 2.  simply attach the two ends of the Duty C wire you cut here - so that it completes the circuit as normal.  then you get normal AWD

 

That's how it's normally done for those that want to "lock" the 4WD themselves.  Your case is a little different though - since you have torque bind so in position #2 you'd also want it in FWD - so actually I think it would be identical to every one else that's ever done it except you'll just leave the FWD fuse in place.

 

Look up your Duty C wire in an FSM - at TCU under the dash above the gas pedal, silver metal box held in place with like 2 screws.  Find the pin out for that one wire there, or in the engine bay at the transmission wiring harness. 



#14 auto2

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Posted 27 April 2014 - 07:43 AM

2 questions, will locked 4wd be better in the snow than awd? and the fwd fuse;there is normally no fuse in it? and putting a fuse in there completes a circut making it only 2wd for towing? but the key has to be on



#15 darsdoug

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Posted 27 April 2014 - 09:56 AM

I've been driving a 96 Legacy LS wagon for a couple years now with the infamous "torque bind" but it just keeps going and going. The FWD fuse never made a bit of difference. The shuddering is always there during tight turns but I hardly notice it anymore. I imagine I should pull the driveshaft going to the rear wheels since I've been to lazy to install a new duty C solenoid in the tailshaft. duh....I was going to take it to GD many moons ago, but I never made it down there.



#16 CNY_Dave

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Posted 27 April 2014 - 02:21 PM

2 questions, will locked 4wd be better in the snow than awd? and the fwd fuse;there is normally no fuse in it? and putting a fuse in there completes a circut making it only 2wd for towing? but the key has to be on

 

No, unless the AWD is not working properly. Going downhill it can be worse, in fact, you hit the brakes and before the fronts have reached their max braking effort, the driveline transfers the braking force to the rear and makes 'em slide.



#17 bgambino

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Posted 28 April 2014 - 11:01 AM

ok...well I'm a little confused

 

How about this?

Since the fuse is now in...and I have FWD with NO TB...this would be my standard mode that I want to be in

 

Now...in the winter, during a storm...I want to flip a switch to go to AWD

Pulling the fuse would accomplish it but I don't want to open the hood

 

Couldn't I just cut both wires going to the firewall fuse holder....run both to the dash to a switch..

 

in the open mode of the switch I have AWD with TB....who cares if its slippery outside...

In the closed mode I have FWD with TB

 

Isn't this way easier?



#18 CNY_Dave

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Posted 28 April 2014 - 09:28 PM

ok...well I'm a little confused

 

How about this?

Since the fuse is now in...and I have FWD with NO TB...this would be my standard mode that I want to be in

 

Now...in the winter, during a storm...I want to flip a switch to go to AWD

Pulling the fuse would accomplish it but I don't want to open the hood

 

Couldn't I just cut both wires going to the firewall fuse holder....run both to the dash to a switch..

 

in the open mode of the switch I have AWD with TB....who cares if its slippery outside...

In the closed mode I have FWD with TB

 

Isn't this way easier?

 

For you, yes. That will work just fine.






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