Did all FT4WD's have a center locking diff? How does it lock, as in what is the mechanism driven by?

Did all FT4WD's have a center locking diff? How does it lock, as in what is the mechanism driven by?

 

To the best of my knowledge, the fulltime 4 wheel drive trannys have center diff locks. According to my Haynes, there is a cable that attatches to the side of the transmission and operates a lever that engages and disengages the center differential lock. I could be wrong though, and I'm sure that if I am, someone will chime in shortly and straighten everything out.

 

Patrick

Not all - the XT6 is a good example of one that did not.

 

Also you should make note that FT4WD and AWD are fucntionally identical - only differing in marketing terms. The early FT4WD was nothing more than the modern 5 speed Legacy transmission you see today. We just call the technology AWD now.

 

Most locking mechanisms are just a lever that engages a pin or cog into the spider gears and stops them from turning.

 

GD

What about the RX's (85-89?) did all their FT4WD boxes have center diff lock?

Only 87-89 RX's were FT4WD (AWD), and yes, all RX models with AWD came with a center diff lock. 85/86 were PT4WD with 1.2:1 low range but still had 2WD.

 

GD

Cheers. Thats pretty much all I wanted to know.

 

Now it's time to go looking for a FT4WD box

Not all - the XT6 is a good example of one that did not.

 

Also you should make note that FT4WD and AWD are fucntionally identical - only differing in marketing terms. The early FT4WD was nothing more than the modern 5 speed Legacy transmission you see today. We just call the technology AWD now.

 

Most locking mechanisms are just a lever that engages a pin or cog into the spider gears and stops them from turning.

 

GD

wrong, evrey ft4wd 5spd xt-6 i have seen has the diff lock, and i think the autos came with it as well but i'm not sure. it is a vaccume accuated servo

I think I am gonna have to just get one and open it up to see what they are like. Unless anyone have pictures of a opened up FT4WD trans?

I think the local USMB guys will have one opened up soon..... New thread on that coming shortly.

 

--E

i think the sutos came with it but i'm not sure. it is a vaccume accuated servo

Dunno what a suto is, maybe you meant auto?

Automatics based on how they work do not have a center diff lock. There is however a mod that you can force the rear clutch pack to be engaged all the time with a switch, making it a 50/50 split.

oh no... don't stoop so low you comment on spelling mistakes.. This forum was going so well without stupid comments lately too (exception given to GD) I know it's all in good fun.

oh no... don't stoop so low you comment on spelling mistakes.. This forum was going so well without stupid comments lately too (exception given to GD) I know it's all in good fun.

your totally right, see mike you had to go and ruin some one's day giving me ************ quit hijacking peoples thread's

also i'll be down tuesday barring someone at work getting sick

Ah - yeah it's the D/R that the XT6 trans lacks. My mistake: It does have the diff lock. Still - it shows the variability of the EA transmissions.....

 

Maybe all the FT4WD EA transmissions here did have the lock. It's still the same basic transmission as the later Legacy AWD's, so it certainly possibly to have one that doesn't have the lock. Although the FT4WD's were usually high-end cars, so probably most (if not all) did have it.

 

GD

Keep it friendly now. I've got all the info I need, so feel free to go off topic or leave this thread to die.

Yes, all Full Time 4WD Trannies for EA82's (usually EA82T's) and XT6's have a locking center diff.

 

Only the RX came with Dual Range Full Time 4WD.

 

-Brian

Check this old thread for pics inside the F/T 4WD trans.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=15410&highlight=anybody+inside+these+trans

 

The difference between the EA F/T MT5 and the EJ AWD is the EA is a open diff with a lock and the EJ has a VLSD center diff. A always open center diff wouldn't be a very good thing.

 

And FWIW... Subaru called it "Full Time 4WD" thu '91, my '91 Legacy SS is F/T, my '92 was "AWD"

 

Gary

Thats awesome! Thanks. So from what I see there the center diff goes between the trans output and rear diff. So the front diff is always connected to the output? And doesn't go through the center diff?

I always kinda wondered where they put the center diff Thanks for sharing.

The front wheel output shaft DOES get coupled to the center diff, it passes throught the gearbox output shaft suspended on needle roller bearings, that's why it at 1st looks like the gearbox output shaft is actually coupled directly to the front Diff when in reality it isn't..This is a true center differential providing differential action between the front and rear drive systems...

hth,

Kaz

The front wheel output shaft DOES get coupled to the center diff, it passes throught the gearbox output shaft suspended on needle roller bearings, that's why it at 1st looks like the gearbox output shaft is actually coupled directly to the front Diff when in reality it isn't..This is a true center differential providing differential action between the front and rear drive systems...

hth,

Kaz

 

Ahh... cheers. That was my other thought to start off with, but there wasn't anything really obvious.

um.....I realize you probably don't care, but the turbo 4EAT FT4WD trannies had no center diff lock.

 

in fact I was under the impression that any non-RX turbo EA82 had FT4WD without center lock.

 

 

 

 

and yes, it is a true center diff. I've got an RX tranny in my loyale, and with no driveshaft in it, I unlocked the center diff, and let out the clutch for a moment. the car didn't move at all. just like it was in neutral.

um.....I realize you probably don't care, but the turbo 4EAT FT4WD trannies had no center diff lock.

 

I can't remember for sure, but I coulda sworn that the FT4WD XT Turbo that was in my area had a diff lock. It's gone now, so I'll never know.

um.....I realize you probably don't care, but the turbo 4EAT FT4WD trannies had no center diff lock.

 

in fact I was under the impression that any non-RX turbo EA82 had FT4WD without center lock.

 

The 4EAT is an auto, and completely different. We aren't talking about auto's here, but yes it's a legacy auto trans basically, and it's got a viscous center coupling rather than a diff in the typical sense of the words. And it can be locked with the right application of voltages. Just like the later auto in the legacy.

 

Most turbo's had the push-button single range, or the regular D/R. Only a few later models had the FT4WD. It was a top-of-the-line option only.

 

GD

Most turbo's had the push-button single range, or the regular D/R. Only a few later models had the FT4WD. It was a top-of-the-line option only.

 

GD

 

huh....ya learn something every day!

my '88 XT turbo has FT4WD and center diff lock, maybe that's somethin that came with the 87,5 face lift session?

Yours is stickshift though Joost.

 

GD, wouldn't the FT4WD 4EAT cars have a clutch pack, and not a viscous coupling?