Hey guys, my dad just bought a 91 legacy wagon and the fwd light is on in the dash. Where should I start trouble shooting? I dont have any experience with awd so any help would be greatly appreciated. Thanks. Ok one more question, I know what the manual button does, but what about the black button on the front of the shifter plate?

Edited January 9, 201115 yr by espey_16

Hey guys, my dad just bought a 91 legacy wagon and the fwd light is on in the dash. Where should I start trouble shooting? I dont have any experience with awd so any help would be greatly appreciated. Thanks.

 

 

there is a fuse hold socket about the size of a zippo lighter, the cap has FWD on it. (if it has a cap still.) it's ion the passenger side under the hood behind the strut tower. pull the fuse and the light goes out. put it in and the light goes on and you have FWD only.

 

but, my guess is that when you pull the fuse you will have ''torque bind'' binding, bucking, shuddering in tight turns. feels like a 4wd truck with the hubs lock on dry pavement. but pull the fuse and see.

 

more info on torque bind:

 

http://www.ultimatesubaru.org/forum/showthread.php?t=119181

 

 

http://www.ultimatesubaru.org/forum/showthread.php?t=78467&highlight=flashing+temp+light

to start with, pop the hood, and pull the fuse out - holder is located at the back of the passenger side strut tower - usually just a 10amp fuse.

 

once you get the fuse out, take it for a drive to see how it handles, reacts - if there is binding on turns, etc. (finding a large empty lot is a great place to check for torque bind)

So if I pull the fuse the awd might come on? When I drove the car I accidentally broke the tires loose but it was only the fronts, the rears didn't kick in.

So if I pull the fuse the awd might come on? When I drove the car I accidentally broke the tires loose but it was only the fronts, the rears didn't kick in.

 

it should.

Ok, I just tried this out. I pulled the fuse it was a 15 amp, and went down the road and did a few u turns but didnt feel any bind. It drove the same as it did with the fuse in.

The fuse is not supposed to be installed. you need to take the fuse out.

 

 

the fuse is for diagnostics trouble shooting the torque bind issues, or if the car was having problems, such as duty C solenoid. Having the fuse in there for long time could have burned up duty C.

Lots of idiot owners put a fuse in there cause they think its supposed to be there. NO NO.

 

you will not get a AWD light with the fuse removed. But you should get awd back with it removed.

 

You sould remove fuse, and have all four corners of the car supported on jackstands. once on jackstands on all 4, put the car in drive and see if the rear wheels are turning. You could also theoretically find a snowy ice patch road, and have someone watch the back tires for spinning action when you mash the gas pedal from a stop.

 

 

report back what you find. and we will go from there.

 

and, are all the tires exact same sizing, with same identical wear?

Edited January 9, 201115 yr by bheinen74

I guess I could go find a gravel road and try breaking the tires loose to see if its working. When I pulled the fuse I only drove slow, I think 35mph max.

Thats weird there's not supposed to be a fuse. I guess I should go take it back out again. Thank you for all the fast replies guys.

Ok one more question, I know what the manual button does, but what about the black button on the front of the shifter plate?

 

that button is for releasing the shifter with the car not running - such as to put it in neutral temporarily (i find this button useful when cleaning the car to get the ashtray out for emptying! LOL)

The tires are all 185/70/14 but they're all mis-matched. They do have about the same amount of tread though.

that button is for releasing the shifter with the car not running - such as to put it in neutral temporarily (i find this button useful when cleaning the car to get the ashtray out for emptying! LOL)

Ok sweet, it was bugging me not knowing what it was for.

that may well have been the reason for the FWD fuse being installed. The AWD tranny's dont particularly like having mismatched tires.

 

a simple check can tellyou if they are close enough in diameters to meet specs however.

 

you will need to measure each tire's diameter - they should all be within 1/4 inch....

you will need to measure each tire's diameter - they should all be within 1/4 inch....

Subaru specifies no more than 1/4" difference in Circumference, not diameter.

 

The tires are all 185/70/14 but they're all mis-matched. They do have about the same amount of tread though.

 

Different brands could mean different circumference. Measure around the outside of each tire. If they are all within 1/4" circumference they should be fine. If not go get a set of 4 new ones.

Hey guys sorry its been so long to update. My dad went and got a couple tires put on the legacy and noticed the rear half of the driveline was missing. So I went to the JY yesterday and got the driveline and the guard that covers the pinion, put them on and took it for a drive. The trip was only about 1/4 mile, then it started making an off and on howling noise. So I limped the car home and put it in the air and started it up. I had my dad put it in drive while I looked under the car to see where the noise was coming from. Its definatly coming from the rear diff. I checked the fluid level, it was black as hell but it was still full. Do you guys think its only the fluid? Or should I go rip off a differential with the same gears and put that one in? Sorry for the long post y'all.

Diff is probably shot.

 

Problem is, what is the reason the driveshaft was removed in the first place? Usually it's because the center transfer unit in the transmission is screwed up (clutch worn, duty solenoid stuck, grooves worn in the drum) causing the car to have torque bind. Your pandoras box has been opened.

 

Plenty of info here about how to get it fixed though. Search for Duty C, Torque bind, center diff, etc. Might even have a thread or three in the "Similar Threads" section at the bottom of the page.

Are there any differences between the 91 and 93 rear diffs other than possibly different gear ratios? I noticed when I picked up the driveline out of the 93, the front half was longer. I'm planning on grabbing the rear out of the same car.

there is a difference between automatic and manual for the driveshaft. The rear part of the shaft is the same, and the diff/axles bolt in the same. You will want to read up which year/trans has the right gear ratios for your car for the rear diff

Yeah I should've thought about that, it was a stick. There were a few wagons from the early 90s there, so if that rear dosnt work I still have options. How would I do a quick junk yard check to see if the diff is any good besides check the oil? My dads rear didn't make that howling right away and it wasn't constant, it was just kind of random. Thanks guys for all the help so far.

Yeah I should've thought about that, it was a stick. There were a few wagons from the early 90s there, so if that rear dosnt work I still have options. How would I do a quick junk yard check to see if the diff is any good besides check the oil? My dads rear didn't make that howling right away and it wasn't constant, it was just kind of random. Thanks guys for all the help so far.

 

 

as stated the front sections of the drive shaft are different between the autos and the manuals. but the 91 auto rear diff and the 93 manual rear diff should be the same, 4.11. assuming turbos are not involved.

 

check here:

 

http://bbs.legacycentral.org/viewtopic.php?t=32148

On the older diffs there is a sticker on the rear cover with a code that you could use to determine what the ratio was. I don't know any of the codes off hand, but I'll try to remember to look them up tomorrow. I know I saw them listed in a FSM somewhere before.

The gear ratio is right on the tag, my dads is 4.111