1998 Imp OS torque bind?

[allwheeldad]

A friend of mine recently scored a really nice 98 Impreza Outback Sport. EJ22, two sets of tires (both almost brand new), and only 124,000 kms on the clock. I was jealous when she told me she only spent $1100.00 for everything. She doesn't have plates on it yet so I could only drive it around the back field, but it seems to be a really strong little car. The only hiccup was that at low speeds with the wheels cranked over there was a lurching hesitation from the rear end. I have searched some of the archives here and I think it sounds like torque bind, which I guess is common. I have never experienced it on any of my subies, so I can't say for sure. I will drain and fill the rear diff for her some time soon, but is there any special additive I should consider using when I do? Is it worth the time to do the front diff at the same time, or is the problem more or less localized at the rear?

[idosubaru]

yep sounds like classic torque bind. good diagnosis and use of USMB resources!

 

the fact that you said "two new tires" sounds like it's probably been mis-maintained. the tires on these 4 wheel drive trans should be rotated frequently and always matching and replaced as a set of 4. replacing 2 tires is generally a bad idea. the quantitative measure from Subaru is that the circumference of all the tires should be within 1/4" of each other.

 

i'd get all the tires matching and change the fluid immediately. start diagnosing from there, lots of information on this here. i would avoid an additive at this point, the tires and fluid change might do it. i'm assuming you know that a drain and refill of the ATF only gets like 1/3 to 1/4 of the fluid out? if the tires and fluid change don't help then i'd entertain an additive...maybe. be very careful and don't just buy any additive, it's generally a bad idea to treat issues with fluids, though there are rare cases when it's a better idea than others. in this case folks have successfully used a GM limited slip additive i think, a search would reveal the type of fluid. but i'd avoid the temptation to just start dumping bottles in.

 

the problem is not with the front diff at all. the problem isn't "in the rear" either, not of the car anyway. it's in the rear extension housing of the transmission.

Edited October 19, 2010 by grossgary

[Suzam]

Put a fuse in the FWD fuse holder under the hood on the passenger side near the firewall (any amp size will do) and see if the problem goes away. If it does then there is a chance that the fluid changes will help. If not then you may have to look for a replacement extension housing on the transmission.

 

If you feel it needs a mechanics touch, find one who has Subaru knowledge. A local mechanic may not be able to diagnose or service the problem without experience with the AWD system.

[WoodsWagon]

Automatic or manual transmission?

 

The problem is not in the front or rear diffs, you can change the gear oil but it will not fix the problem. The binding is in the transmission.

 

If it's an automatic, put the FWD fuse in (take a spare out of the under hood fuse box and put it in the fuse holder up on the passenger side strut tower that says FWD. Then drive in circles. If the binding is gone while the fuse is in and FWD is lit up on the dash, then all you need to do is change the automatic transmission fluid a few times. If the binding is still there with FWD lit up on the dash, then you need to take apart the transfer housing on the back of the transmission and start replacing parts. Same thing if the AT temp light flashes 16 times when you start the car.

 

If it's a manual, then the problem is in the center differential. No fluid change will fix that, the limited slip portion of it (viscous coupler) is a sealed unit. So you have to replace that, which means you need to pull the rear transfer housing off the transmission.

 

We need a damn torque bind sticky at the top of the new gen forum.

[allwheeldad]

Thank you for all your responses. I try not to bug anybody here unless I have to, I realise it gets tiresome repeating advice and information you have previously laid out (trust me, I have two young kids, I know ALL about it:grin:). I did forget to mention that it was an an automatic and that it came with two sets of tires, those being snow tires and summer tires. Sorry if that led to confusion the way I wrote it earlier. I have a tread depth gauge and each seperate set measured nearly identically to each other, so I eliminated tires as an immediate culprit. However, that doesn't mean that the tires that were on there before these were any good and may have led to some issues now. My friend lives in another town an hour or so away and I really don't have the time to work on my cars and hers. If it is something that can't be remedied with a couple easy fluid changes then she is going to have to take it to a shop. I'll do the FWD fuse operation and see where that gets me.

[johnceggleston]

if the fuse eliminates the problem then the duty c is good and the problem is either the actual transfer clutch plates or "gunk". (gunk is a technical term.) the fluid changes may help with gunk, maybe immediately or over time. some folks have reported some success with new fluid and driving backwards in tight circles. (reverse may help dislodge ''gunk", but it may not. if it helps, i would change the fluid again.) draining the trans oil pan and then re-filling with the same amount, and then driving around the block and then doing it twice more will give you about 80% new fluid depending on how much drains out each time. or go to the shop and pay $125? for a flush.

 

if all of that does not help, then you / she is looking at a repair in the 900$ range at the dealer maybe less at an independent subaru shop. you can buy the parts on line for about 300$, (including the duty c) i think.

Edited October 19, 2010 by johnceggleston

[lmdew]

Is the fluid temp light flashing 16 times after she starts the car?

 

If so there is a trouble code stored in the TCU.

 

If the FWD fails to come on when the fuse is put in and the light is flashing it's most likely electrical wiring/circuit problems.

[allwheeldad]

There is no flashing temp light at startup, just a CEL. I did a code scan and it came up with a 0440 code. I went through the usual inspections for that and the most obvious thing jumped out at me; rusted fuel filler neck. It still has the salt trap shroud on it and what looks like the original pipe, so I imagine I will be changing that out soon as well. This woman is on a pretty tight budget so as long as it isn't dumping fuel on the ground she isn't going to spend the money on the filler neck. A little time and cash on fluids changes is one thing, but more expensive parts is another. I'm a full-time student again (thanks recession) so my time is at a premium right now. I'm just trying to help her out. I won't be getting back to her place for a couple weeks, but I'll dig this thread back out and let everyone know how I made out. Thanks again for all the input.

[Fairtax4me]

(reverse may help dislodge ''gunk", but it may not. if it helps, i would change the fluid again.)

Funny you mention that. I knew a guy who swore up and down that the only way to "flush" an auto transmission was to drain and refill the fluid, then put it in reverse and drive around backwards as fast as it could go for about 15 minutes, then change the fluid again. I still don't see exactly how it helps.

Though in this case I can see some reasoning behind it. The clutch plates in the transfer unit will spin the opposite direction which may (or may not) allow them to slip again rather than sticking together and causing the binding.

 

Need some friction modifier additive for the transmission. (I'm just kidding don't actually put friction modifier in the transmission. That would be bad ).