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Full Time 4WD?


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15 replies to this topic

#1 Bob E.

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Posted 08 March 2007 - 11:10 AM

When did subaru switch over from part time to full time 4wd?

#2 jeep5.9litre

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Posted 08 March 2007 - 11:51 AM

Do you mean to All Wheel Drive?

#3 Bob E.

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Posted 08 March 2007 - 11:55 AM

yup

#4 jeep5.9litre

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Posted 08 March 2007 - 11:57 AM

I beleive they started the AWD in the Legacy model line in late 1989-early 1990 and kept the pushbutton 4WD on the loyale until 1994.

#5 mikeshoup

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Posted 08 March 2007 - 12:16 PM

FT4WD was offered starting in 88 on upscale Turbo models, some XTs and XT Turbos, and the XT6. All of the EJ series (Legacy, Impreza, etc), are offered with AWD.

#6 86subaru

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Posted 08 March 2007 - 09:19 PM

i have a 88 full time 4wd turbo wagon , a/t :Flame:

#7 Phizinza

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Posted 08 March 2007 - 10:09 PM

FT4WD and AWD in the Subaru world have differences. They are, AWD has center VLSD differential. FT4WD has open center differential. AWD is better, but the FT4WD came with a center locking differential. Which if the like rough terrain, then FT4WD is much better, but that is the only case it is better that I know of.

Loyal shaped Subarus never came in "AWD" and Legacy shaped Subarus never came in "FT4WD" although for a while I think they called there AWD system in the Legacy "Full Time 4WD".

I just thought I'd come along and confuse you all.

EDIT: Oh, then theres Autos... Which are completely different and in my point of view have a very simple AWD/FT4WD. They use a clutch pack in the center (no diff) which engauges when the front wheels slip. I've seen so many videos of all kinds of cars with this system 4WDing and they aren't good at all...

#8 Gloyale

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Posted 08 March 2007 - 10:31 PM

FT4WD and AWD in the Subaru world have differences. They are, AWD has center VLSD differential. FT4WD has open center differential. AWD is better, but the FT4WD came with a center locking differential. Which if the like rough terrain, then FT4WD is much better, but that is the only case it is better that I know of.

Loyal shaped Subarus never came in "AWD" and Legacy shaped Subarus never came in "FT4WD" although for a while I think they called there AWD system in the Legacy "Full Time 4WD".

I just thought I'd come along and confuse you all.

EDIT: Oh, then theres Autos... Which are completely different and in my point of view have a very simple AWD/FT4WD. They use a clutch pack in the center (no diff) which engauges when the front wheels slip. I've seen so many videos of all kinds of cars with this system 4WDing and they aren't good at all...


FT4WD=AWD. only difference is the terminology. AWD abrieviates easy and rolls off the tongue. That's the only difference. heres why:

First, Many AWD Subarus have an open center diff. Not all are viscous.

Second the automatic FT4wd and AWD are basically the same. They are all 4EATs. a few minor changes to the trans over the years but still the same function. They rely on the TCU(computer) to decide how much torque to send to the rear. My 93 Legacy does a great job controlling it in the snow. My 89 GL "FULLTIME" not so much. I used a switch to interupt power to the Transfer solenoid which locks the car in 4wd like an old 3spd Part time auto.

I do not agree with Phizinza about the automatics off road performance. And I'm not relying on video, but my own experience. No Subaru without some modifications is a true "Off-Road" vehicle, but both my automatics hold there own in mud, snow and gravel. I've never been stuck unless it was a clearance issue. In which case it doesn't matter if you've got a triple nuclear super tranny, you're stuck.

#9 Phizinza

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Posted 08 March 2007 - 10:51 PM

Wow... I never knew this. Can anyone shed light on which didn't? My 89 Liberty/Legacy had a VLSD center. I thought they were all VLSD centers in the "new gens."

First, Many AWD Subarus have an open center diff. Not all are viscous.

I do not agree with Phizinza about the automatics off road performance. And I'm not relying on video, but my own experience.

I am glad you have had success with your auto. I haven't driven one offroad, so I guess just seeing how much better my car is then someone elses auto doesn't count as good as your experience. Thanks for your imput.

As you may of read, I said "FT4WD and AWD in the Subaru world have differences." But of cause this is all just a point of view on what people refer to as FT4WD.

edit: Ok, for interest's sake I thought I'd look on the net for what the general definition of FT4WD is. On Wiki I found that it is refered to as having a center differential and low range. Where the AWD system only has single range and a center differential. I can't seem to find any manufactures notes on what FT4WD is.
You could call it a early step to AWD, but then why are there big 4x4's coming out now that have "Full Time 4WD" on them, as in it's a huge step for 4x4 kind.
"That's so 1980's"

#10 calebz

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Posted 08 March 2007 - 10:55 PM

The correct generalized answer is 1987

#11 mikeshoup

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Posted 08 March 2007 - 11:18 PM

First, Many AWD Subarus have an open center diff. Not all are viscous.

Which ones? It was my understanding all EJs have a viscous center, EAs don't.

#12 Numbchux

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Posted 09 March 2007 - 12:00 AM

First, Many AWD Subarus have an open center diff.


sorry....but that's 100% wrong. the autos aren't viscous, but they have a clutch pack that limits the slip....but ALL AWD EJ subarus have a limited slip center diff. of somesort.

I will agree with you in that the 4EAT FT4WD and AWD trannies are the same. but both have the clutch pack limited slip, favoring the front. which, in an extreme offroad situation (one that you probably can't get in without a lift), will slip.


phiz has it right (be sure to read his edit....he's got ATs covered too)

#13 Gloyale

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Posted 09 March 2007 - 12:14 AM

sorry....but that's 100% wrong. the autos aren't viscous, but they have a clutch pack that limits the slip....but ALL AWD EJ subarus have a limited slip center diff. of somesort.

I will agree with you in that the 4EAT FT4WD and AWD trannies are the same. but both have the clutch pack limited slip, favoring the front. which, in an extreme offroad situation (one that you probably can't get in without a lift), will slip.


phiz has it right (be sure to read his edit....he's got ATs covered too)



Well I was just searching to try to find the post. But I swear there was someone talkin about a Legacy w/MT that was stuck with one wheel spinning in snow. That to me sounds like an open diff. Legacies came out in late 89 and I didn't think the viscous center came standard till 91. And I swore the guy who was stuck had a 97ish OBW. If I am wrong so be, but the viscous units are not always any better than an open diff anyhow.

I read his edit. I think we're splitting hairs, my point is that really other than the name, there is no difference between AWD/FT4wd. Both are basically the same in design and function, MT or AUTO respectively. The later AWD's are still the same trans design just with a limited slip. If there had been a limited slip center offered in the old FT4wd, would they have called it anything different? Probably not. It's all marketing, and which name "tested" better with the sales department.

#14 Phizinza

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Posted 09 March 2007 - 12:21 AM

Everyone here has a point.

What mine is simplyfide:
FT4WD in a Subaru means center diff with a locking option.
AWD in a Subaru means viscous center diff.

So in my mind, even though they use similar gearbox designs, they are quite different in operation and should be treated as quite different gearboxes.


As for AWD leg spinning one wheel: This is why I built my EJ FT4WD trans. Diff lock rules. The AWD center VLSD really isn't up to offroading IMHO. As for auto's, well you know what I think about that already.

#15 Numbchux

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Posted 09 March 2007 - 02:23 AM

I read his edit. I think we're splitting hairs, my point is that really other than the name, there is no difference between AWD/FT4wd. Both are basically the same in design and function, MT or AUTO respectively


we are splitting hairs to a point, but I don't want the wrong information to go unchecked.

they're basically the same in design. the ATs are identical, but the MTs are very different in function. take them both on the street and try to accel hard while turning hard. with a FT4WD MT, you get nothing but wheelspin at one front corner, do it with AWD, and the viscous center is strong enough to allow the car to actually accelerate.

or in the deep snow (like we've had for the last few days), if I forget to lock up my center, I just spin a front wheel. lock it up, and that all changes. the viscous would be enough to get me through most of that without the locker.

a limited slip is just that, it does still allow slip, so in some situations, it will allow all the power to go to one side, and they also wear out, so the effectiveness might vary. but all EJ AWDs came with a LSD center, MTs with a viscous, and ATs with a mechanical clutch pack.

#16 Phizinza

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Posted 09 March 2007 - 08:12 PM

I don't want to bring this topic back up, but...

but all EJ AWDs came with a LSD center, MTs with a viscous, and ATs with a mechanical clutch pack.

Am I wrong in saying an Auto does not have a differential? When we say a center LSD (limited slip differential) in a auto works like so, blah blah. I just can't get to grips with it. I can't call it a diff because it is purely just a clutch. So, have I got this all wrong, and the meaning of differential basicly means difference in speed, or difference in torque in cars. Or should a diff be called a diff and a center clutch pack be called a center clutch pack?
For some reason, saying a Subaru AWD/FT4WD auto has a center LSD just doesn't sit right with me.




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