Question about 4WD

heathcom · Post by **heathcom** » Tue Dec 11, 2007 3:39 pm

I have a 91 Legacy, says all time 4WD on the dash. We just had our first big dump of snow here in Maine and I was expecting it to drive a bit better. I have a slight incline in the driveway and it felt like any front wheel drive car with the tires slipping in the snow. Didnt notice the rear wheels at all. Are these cars just like any other 4WD vehicle or is it some kind of "limited slip" type thing?

vrg3 · Post by **vrg3** » Tue Dec 11, 2007 4:32 pm

You don't say what kind of transmission you have. Automatics have a completely different all-wheel-drive system from manuals.

Your car is (or is supposed to be) full-time four-wheel-drive. There have been some cases with automatics where people have had their cars drive only the front wheels; you may be able to find a thread or two about it by searching.

heathcom · Post by **heathcom** » Tue Dec 11, 2007 4:58 pm

sorry, its an automatic. I was hoping its supposed to drive better in the snow, and hopefully not a big problem......

This may be a related problem. I get a nice kick going into second gear and than a little slide into 3rd. It maybe the speedo cable is a little off, takes a few seconds to catch up to the speed.

vrg3 · Post by **vrg3** » Tue Dec 11, 2007 5:09 pm

It may or not be related; I'm not familiar with the autos -- for all I know this problem could be resolved with a fluid flush and fill.

There are several board members who are well versed in the 4EAT. I suggest you spend some time searching for their posts.

jamal · Post by **jamal** » Tue Dec 11, 2007 6:46 pm

it may just be related to your tires not being any good.

When you put the gear selector in 1 it forces the center clutches to "lock up." Try that and see if it makes a difference.

ericem · Post by **ericem** » Tue Dec 11, 2007 9:43 pm

You said your speedo is not responding quickly? There is a speed sensor in the speedo. So if its detecting the front wheels not moving as fast as the rear wheels which has its own sensor it will go FWD. I suggest you get another speedo cable as they are only like $20 since it can create issues with the transmission shifting and the AWD.

What is the mileage on your car by the way?

Murphy · Post by **Murphy** » Tue Dec 11, 2007 10:50 pm

mine used to not lock up at all, i took it mudding practically in FWD, i had it in 1st and it wouldnt lock until like 5k rpms
i think its supposed to lock up in slipping conditions, and when you are at WOT it locks up, also 1st is supposed to be locked up, and ive noticed sometimes mine feels like its trying to lock up when i hit 3k rpms

i got tired of that, so i rigged up a switched to manually control it, with the switch off, the system operates normally, and will lock up normally, but with the switch on, it is locked up all the time, and behaves like a 4x4 truck, unless the clutches are burnt than you defiantly wont have problems with traction
heres a link if your interested at all
http://bbs.legacycentral.org/viewtopic.php?t=33061

you could of course have burnt out clutches, in which case, it needs to be rebuilt, or just get the clutches and steels. i would start with the simplest thing, check the fluid
but im definatilly not an excpert on this

speedoboy31 · Post by **speedoboy31** » Wed Dec 12, 2007 4:21 am

murphy, you had the same idea i did. i rigged up a switch to drop the power to solenoid c. it worked great,but the 4eat took a dive after a couple real hot suppers and the rest of the car didn't warrant a re-build-----car scrapped except for the engine.

ciper · Post by **ciper** » Wed Dec 12, 2007 9:29 am

The automatic transmission relies heavily on the speed sensors so that it knows when to tighten the clutches.

The dash says AWD not 4WD.

Are you sure the rear wheels werent turning? It could have been that one rear wheel was turning while the other stood still.

All_talk · Post by **All_talk** » Wed Dec 12, 2007 2:19 pm

ciper wrote:The automatic transmission relies heavily on the speed sensors so that it knows when to tighten the clutches.

The dash says AWD not 4WD.

Are you sure the rear wheels werent turning? It could have been that one rear wheel was turning while the other stood still.

I thought the same, with the open rear diff you can get one front and one rear wheel spinning.

And BTW, thru 1991 Suabru still called it "Full Time 4WD" (started with the EA L series cars), and yes there was a sticker on the gauge bezel.

Gary

Murphy · Post by **Murphy** » Wed Dec 12, 2007 10:53 pm

ciper wrote:Are you sure the rear wheels werent turning? It could have been that one rear wheel was turning while the other stood still.

i think you would be able to notice it in the way the engine revs and you can just feel a difference, its subtle but you'll notice it
when mine locks it revs much slower, even if the wheels are spinning

what kind of tires do you have?

heathcom · Post by **heathcom** » Fri Dec 14, 2007 3:29 pm

Its got over 250,000 miles, tires are decent enough. Ive driven on worse tires in worse conditions. Definately worth changing the fluid which I hope to do this weekend. Were expecting a big snow storm Sunday. Im guessing theres a tranny filter in there too. The speedo cable will be next and hope its not burnt clutches.
It does feel like every FWD car Ive ever driven. No changes that I noticed when I tried 1st gear, manual swith etc... I had my son look at the tires when I drove up the driveway in the snow and said the rear tires just rolled with the car while the fronts spun in the snow.
We'll see what happens. That manual switch sounds like a great idea. Thanks for all the info ; )

also, if anyone knows which wires it would be on a 91 legacy, might save some diggin time.

ericem · Post by **ericem** » Fri Dec 14, 2007 9:12 pm

At that mileage very possible its time to rebuild it. There is a external filter, dont remove the tranny pan. The filter in there leave. Just change the fluid and see if the external filter was changed. I think they updated the filter or removed it all together?? It may have already been done but check anyway. Make sure when you check the level of the fluid that the car is level and running. Fill some fluid first before starting btw.

ciper · Post by **ciper** » Sat Dec 15, 2007 1:08 am

All_talk wrote:
ciper wrote: I thought the same, with the open rear diff you can get one front and one rear wheel spinning.

And BTW, thru 1991 Suabru still called it "Full Time 4WD" (started with the EA L series cars), and yes there was a sticker on the gauge bezel.

Gary

Its not too hard to retrofit an LSD into the open differential. I did this on my wagon because I was getting two wheel spin.

There is an old thread on here somewhere about the AWD/4WD thing. Don't you think its odd that the "4" on your sticker is highly stylized to looke like an A?

heathcom · Post by **heathcom** » Sat Dec 15, 2007 5:16 am

Is it possible to find out if its more a mechanical failure by putting it up on blocks and see if all 4 tires spin? Or does it need actual "slippage" in the front to engage the rears?
Id hate to put the switch in and it not do anything.....

ericem · Post by **ericem** » Sat Dec 15, 2007 5:59 am

What I did to test it was lift the front of the car with a car jack. I lifted it by the cross member then reved the motor a bit to see if it engages.

ciper · Post by **ciper** » Sat Dec 15, 2007 12:49 pm

Ericem: That is just not safe in any fashion.

heathcom: Put the car up on 4 jack stands and have a helper put it in drive. Pull the parking brake up and see how much it can fight the brake.

ericem · Post by **ericem** » Sun Dec 16, 2007 12:06 am

Ya I know lol but I didn't go anywhere I just wanted to see if it would engage. Where I lifted the front of the car from is very strong anyway.

heathcom · Post by **heathcom** » Sun Dec 23, 2007 5:17 pm

I bought myself a car jack for christmas and got the car up on blocks. I figured if it was a mechanical issue there'd be some noise or movement somewhere but got absolutely nothing but the front tires. I ended up putting a switch to bypass the puter as suggested and voila! I tried to get myself stuck in the driveway where I didnt shovel but made it out without too much trouble. What a difference. I cant believe I got this car for 250.00
Is it the C solenoid that causes this problem or something else? Id just like to know for future reference. I am now a dedicated Subaru fan. ; )

ericem · Post by **ericem** » Sun Dec 23, 2007 6:53 pm

Could be the speedo cable affecting the front sensor. Might still be worn out clutch. Did you do the tranny fluid change? But anyway WOW! Only $250!! Amazing. Have fun.

Murphy · Post by **Murphy** » Sun Dec 23, 2007 11:44 pm

my theory is that maybe if it is harldy ever used, it will stop working. kind of like 4x4 trucks that have the electronic push button transfer-case engagement, if you dont use it the motor that engages it will freeze up over time.
the C solenoid always has power to it during normal driving, and it keeps pressure off of the clutches, when the TCU wants to go into AWD, it cuts power to the solenoid and dumps tranny fluid to the clutches to lock them up

but i did notice that after i used my switch a few times, the TCU started engaging AWD properly again. so its working now pretty much, but it will not stay locked, so i always use the switch if i am off road or something

davidson 5139 · Post by **davidson 5139** » Mon Jan 07, 2008 12:11 am

I have a question about my tranny. I have a 91 legacy sport with a auto and the only gear i have is like 3rd. could that be a senser or somthing because sometimes the spedo dont work. i have 0nly drove the car once because i thought it might just need a whole new trans and have been looking for one but if it is just a senser that would be great.thank

Post by **Legacy777** » Mon Jan 07, 2008 7:36 pm

It could be a contributing cause, but the likelihood is that the trans is shot, and needs a rebuild.

davidson 5139 · Post by **davidson 5139** » Wed Jan 09, 2008 3:27 am

THANK YOU VERY MUCH. I JUST FOUND A DONOR CAR WITH A AUTO TRANS.

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Question about 4WD

Question about 4WD