Stupid quest. about torque bind AFTER a trans change.

[Green96GT]

My front diff fried, so I had a shop put in a whole new (used) trans and diff, and a rear diff to match. I didn't have torque bind before, but I've got a bad case of it now.

 

The garage eff'd up, didn't they? I can demand that they fix it right?

 

I told you it was a stupid question!

[lmdew]

Used parts are BBW unless they have a return policy. Then they will only give you another used part, may be good, may be bad.

 

Labor is always at your expense. If the garage was not inside the trans, they didn't do anything that would cause torque bind. Does it go into the FWD mode when the fuse is installed?

[Dr. RX]

So, I'm going to assume that this is a 96 Subaru, so it will be AWD. Is it an automatic or standard? It seems to me that the front and rear don't match. Unless you got the tranny and rear diff out of the same car, how would you know that they match? Most wrecking yards could care less about the diff ratios, all they car about is what make (and somethings model) of car it came out of. If you got parts off a shelf at a wrecking yard, it is possible that you got a mismatch. Subaru no longer has the neat metcals on the back of the diff telling you what the ration is, so it is hard to determine what the ratio is. I understand that there is a code that Subaru does paint on the diff, but I haven't found a reliable source for that code. And even if you know what the rear diff is, how would you know what the tranny ratio is. The best way is to look at the dataplate on the car, assuming that it still has it original tranny, it will have the tranny model number on the dataplate. You should be able to call a Subaru dealer's part department and get them to find out the ratio using that number. Sometimes there is a decal still attached to the tranny with the model number of the tranny on it, you might look on the bell housing near the center top. Another problem could be (if a standard tranny) that the center diff is frozen, that will cause the front to back binding. I have a lockable center diff, and I can cause the wheels to bind on pavement if I lock it up. Hope this helps.

[idosubaru]

first - call the mechanic and tell him to hold on to the old transmission, don't let him throw it away.

 

my guesses in order of probability:

Diffs are different ratio (don't trust yards or mechanics)

Duty Solenoid C isn't getting power (not connected or wire cut during install - only way it could be mechanics fault, not likely)

Used trans has torque bind

 

details on above items:

you need to verify the rear and front diffs are for sure, absolutely the same ratio. don't worry about what you were told or what the junk yard said, physically check to make sure the final drive ratio is identical on the front and rear. with the entire car off the ground you should be able to turn the front wheels 10, 20, or 40 times or so and count how many revolutions the rears make. if the front turns 37 and the rear turns 40, you know they don't match.

 

next you need to make sure Duty Solenoid C has power to it, if it's not plugged in or doesn't have power you will get the situation you are experiencing now. could be a dirty connection, bent pin, cut wire, or just not connected at all.

 

if this checks out, it's likely the trans had torque bind previously. try a fluid change before assuming the trans is bad. if you think it's torque bind you can replace the rear extension housing, you don't need an entirely new transmission. if you have your old transmission you can likely swap the rear extension housing with it. you said you didn't have torque bind before, so your transfer clutches in your old trans should be fine. swap those, this can be done without removing the transmission. that's a bonus. if you don't have your old transmission, then maybe the yard will give you a rear extension housing to swap? or you'll have to yank and exchange the entire transmission.

[kimokalihi]

I made the mistake of not checking the ratio of the donor car and my car's diff. Turns out mine was 4.111 but the donor was 3.90 and this caused a huge problem when I test drove it. The moron who sold me the car told me the rear diff was bad and that was the cause of the noise you'd hear driving down the road(turned out to be two bad wheel bearings)and I I stupidly replaced the rear diff with a different ratio one. It seemed ok at very low speeds but once you hit probably 20 mph+ it sounded horrible.

 

My friend told me it was the wheel bearings and we lifted the car and spun the wheels by hand and it was definately the bearings. Those are replaced and now the noise went away and like a week later the transmission died on me so I had to replace all that stuff anyway. Luckily I knew to look for the ratio first(on the back of the rear diff there's a sticker that shows it, you may have to wipe off the dirt to see it).

 

The guys at the junkyard told me that all the subaru 90-92or94? legacy's have the same ratio diffs in them. He was wrong. And then that idiot went so far as to tell me that even if it didn't have the same ratio, it wouldn't matter. I hate that guy. I hope they fire him. He's an rump roast and he's stupid.

 

So never trust the guys at the junkyard.

[idosubaru]

that idiot went so far as to tell me that even if it didn't have the same ratio, it wouldn't matter. I hate that guy. I hope they fire him. He's an rump roast and he's stupid.

HA HA HAAAAA AHAAHAHAAAH!!!!

i hate that you went through that mess, but DANG that was funny!! love the reply, thanks for being honest that's what i'm talking about! thanks for adding humor to a beautiful day!

[idosubaru]

i just read it again and laughed again...WOO HOO!!! i don't know why that is so funny, it just is.

[nipper]

My front diff fried, so I had a shop put in a whole new (used) trans and diff, and a rear diff to match. I didn't have torque bind before, but I've got a bad case of it now.

 

The garage eff'd up, didn't they? I can demand that they fix it right?

 

I told you it was a stupid question!

 

The garage did not f up. Its a risk with used transmissions. Sometimes its better to rebuild the awd unit while the tranny is out of the car, especially if its a tranny with an unknown history.

Unless you test drove the doner car, there is no way to know if it has TB without opening it up.

 

nipper

[Green96GT]

This shop does Subies exclusively, and is considered to be the best in the area by far . When I first talked to them about the repair they explained the issue about matching the front and rear ratios, and said they needed to see if they had two that matched. I assume they did their homework on this. They also said they would inspect the new one, do a power flush on it as well.

 

I'll talk to them on Monday and see what they can do.

[idosubaru]

check to see if duty solenoid C has 12 volts.

if it goes away with the FWD fuse in then that should rule out any Duty Solenoid C issues (at least connectivity issues).

check diffs (and check again, this has been seen before)

[xoomer]

i just read it again and laughed again...WOO HOO!!! i don't know why that is so funny, it just is.

 

'Because its not you... (its all fun and games until you end up in a dress)

[Dr. RX]

This shop does Subies exclusively, and is considered to be the best in the area by far . When I first talked to them about the repair they explained the issue about matching the front and rear ratios, and said they needed to see if they had two that matched. I assume they did their homework on this. They also said they would inspect the new one, do a power flush on it as well.

 

I'll talk to them on Monday and see what they can do.

So it is an automatic. Then most of what I said about the center diff will not apply.