Power distribustion on AWD models

[My99LaserAWD]

does anyone know what the power distribustion between the front and read wheels is on DSM;s and is it different for 1g and 2g's or is it the same?

 

[c0degsx]

my friend has a wrx......he does not have a center dif. neither does my cousins wrx.

 

[steve]

Originally posted by 90AWDTalon
I think I believe what Mitsubishi says from the factory. Viscous rear, open front and center. If not why would they say so?

Don't know where you read that.

The center diff has a VCU on it stock on 1G, 2G, GVR4, 3kGT VR4, AWD Stealth and I believe some EVO's.
A rear VCU LSD was an option on 1G's (may be std on 2G's) but prior to '92 you couldn't have ABS and rear LSD. The front diff is open unless you install an aftermarket unit.

 

[90AWDTalon]

Originally posted by steve
Don't know where you read that.

I read it on my door jam.

 

[steve]

Originally posted by 90AWDTalon
I read it on my door jam.

So, read it again. It says you have a VCU LSD in the rear diff, that was an option. It doesn't say anything about your center or front diff. Again all AWD DSM's have a VCU on the center diff, it was standard equipment.

Steve

 

[90AWDTalon]

I did a little research and our cars come with a viscous coupler, but it is my understanding that a viscous coupler and a center differential are seperate parts. I read the VFAQ on replacing the the center diff and the viscous coupler gets removed a couple of steps before the center diff gets removed. I'm a little confused on this part, but I know I'm right about the rear.

 

[steve]

Originally posted by 90AWDTalon
I did a little research and our cars come with a viscous coupler, but it is my understanding that a viscous coupler and a center differential are seperate parts. I read the VFAQ on replacing the the center diff and the viscous coupler gets removed a couple of steps before the center diff gets removed. I'm a little confused on this part, but I know I'm right about the rear.

Your research is correct. the VCU for the center diff isn't inside the diff. It's right under the first cover but it is attached to both output shafts of the center diff. Your correct about your car but not all AWD 1G's have rear LSD.
Pre-'92 cars with ABS do not have LSD because the version of the ABS used wouldn't work with it. Pre-'92 cars without ABS may have a rear LSD if they were ordered with it and if they do they have that orange sticker (actually all DSM's with a rear VCU have the orange sticker if the factory installed it). '92 and later 1G's AWD's may have the rear LSD no matter if they have ABS or not. In '92 they improved the ABS to work with a rear VCU. I stopped following all the options on 2G's so I don't know for sure if the rear VCU ever became standard equipment or remained an option.

Steve

 

[90AWDTalon]

Originally posted by steve

Your research is correct. the VCU for the center diff isn't inside the diff. It's right under the first cover but it is attached to both output shafts of the center diff. Your correct about your car but not all AWD 1G's have rear LSD.
Pre-'92 cars with ABS do not have LSD because the version of the ABS used wouldn't work with it. Pre-'92 cars without ABS may have a rear LSD if they were ordered with it and if they do they have that orange sticker (actually all DSM's with a rear VCU have the orange sticker if the factory installed it). '92 and later 1G's AWD's may have the rear LSD no matter if they have ABS or not. In '92 they improved the ABS to work with a rear VCU. I stopped following all the options on 2G's so I don't know for sure if the rear VCU ever became standard equipment or remained an option.

Steve

Does the rear diff work in the same way, a viscous coupler attached to a normal diff or is it different? Any idea why Mitsubishi had a warning for the rear diff but not the center?

 

[steve]

Originally posted by 90AWDTalon
Does the rear diff work in the same way, a viscous coupler attached to a normal diff or is it different? Any idea why Mitsubishi had a warning for the rear diff but not the center?

The VCU is "inside" the rear diff but it works pretty much the same way. Both axles run into the VCU.

IIRC, if you flip down the drivers sun visor you'll find a warning for towing. It's also in the owners manual and the service manuals.

Steve

 

[steve]

I didn't recall correctly about the visor. I checked this morning when I went to warm the car up and the visor just talks about turbo and child safety. The AWD towing warning is in the manuals.

Steve

 

[Keaka26]

Hah, i knew i was right =) ...

 

[steve]

Originally posted by Keaka26
no no , front is open, center is always a viscous limited slip, rear is either open or a 1.5 way clutch type limited slip.

Not about the rear. It's not a clutch type...

Steve

 

[Keaka26]

ahh damn, you're right...haha, too bad...my bad.

anyways, does subaru really run an open center diff? Ive raced quite a few and they get tons of wheelspin... terrible....

 

[90AWDTalon]

Originally posted by steve
I didn't recall correctly about the visor. I checked this morning when I went to warm the car up and the visor just talks about turbo and child safety. The AWD towing warning is in the manuals.

Steve

Thanks.

 

[My99LaserAWD]

U sure about the subaru's not having center diff? i htought they did

 

[steve]

According to subaru's web site all manual transmission equiped AWD cars have a VCU coupled center diff with a normal 50/50 split.

Active AWD is available on some models with automatic trans and have a continously variable transfer clutch.

WRX's with AT have a planetary center diff with a hydraulic transfer clutch with a normal 45/55 split.

http://www.subaru.com/allwheeldrive/all_wheel_middle.jsp

Steve

 

[Defiant]

Whoa, cool, Subaru finally realizes which end of the car is _supposed_ to drive. There is some hope after all.

 

[Keaka26]

I heard subaru has a gear based power split....like 70-30 in first, 60-40, then 50 - 50 in third + .....it would make sense because i always hear subarus make crazy wheelsping off the line....where as DSMs seem to just take off...