Transfer Case Removal

[svx_commuter]

I have my car at a transmission shop to get the rear wheel drive fixed. The rest of the transmission is working okay but not the rear wheel drive.

Has any one ever had just the transfer case removed from their car and repaired? The service manual says this can be done and I wanted to know if it could really be done.

[svx_commuter]

Well I just called the shop and there is no line pressure in the transfer case. Does this sound familar to any one? He says it may be a problem with the TPS not being picked up by the TCU.

[eddycat2000]

Originally posted by svx_commuter
I have my car at a transmission shop to get the rear wheel drive fixed. The rest of the transmission is working okay but not the rear wheel drive.

Has any one ever had just the transfer case removed from their car and repaired? The service manual says this can be done and I wnated to know if it could really be done.

1. You don't have a transfer case.

2. The extension housing can be removed while the transmission is in the car. (That's where the transfer clutch assy lives.)

[eddycat2000]

Originally posted by svx_commuter
Well I just called the shop and there is no line pressure in the transfer case. Does this sound familar to any one? He says it may be a problem with the TPS not being picked up by the TCU.

I think I'd look for a second opinion. I've never seen a TPS cause a transmission problem...right Aredub?;)

I'd more likely suspect either a plugged orifice, (someone may have had the FWD fuse installed too long), or an open circuit in the transfer solenoid circuit.

[vkykam]

Do you have the blinking power light when you start the car?

Have you looked at one of the FAQ's to try to pull what the error codes are yourself? Might give you an indication as to what the problem might be.

Chris/Sith: If I were to make .mpg's or step-by-step with pic's of the tranny code retrieval, check engine light code retrieval, or anything else simple (I'm open to suggestions here), could you host it here, maybe under a D-I-Y'er section?

VK


Originally posted by svx_commuter
Well I just called the shop and there is no line pressure in the transfer case. Does this sound familar to any one? He says it may be a problem with the TPS not being picked up by the TCU.

[svx_commuter]

Originally posted by eddycat2000


I think I'd look for a second opinion. I've never seen a TPS cause a transmission problem...right Aredub?;)

I'd more likely suspect either a plugged orifice, (someone may have had the FWD fuse installed too long), or an open circuit in the transfer solenoid circuit.

Thanks and I was talking about the back end of the tranmission being the transfer case in the case of the SVX. Can't I call it a transfer case?

The transfer clucth is operated by duty solenoid "C" and the way I understand it if the power is off to solenoid "C" the car is supposed to be in AWD. Or am I missing something? I was planing on disconnecting the the wire to "C" from the TCU to check this out.

Clogged orifice where? Still in the transfer case? or in the hydraulic control valve unit? Is there any easy way to check for this and maybe a way to flush it out without removing the transfer case?

[svx_commuter]

I have checked for transmission codes and the car does not have any. It says that everything is okay.

Originally posted by vkykam
Do you have the blinking power light when you start the car?

Have you looked at one of the FAQ's to try to pull what the error codes are yourself? Might give you an indication as to what the problem might be.

Chris/Sith: If I were to make .mpg's or step-by-step with pic's of the tranny code retrieval, check engine light code retrieval, or anything else simple (I'm open to suggestions here), could you host it here, maybe under a D-I-Y'er section?

VK




I am picking up my car and I am going to check out the TCU and related items. Any ideas would be welcomed. At least I know it is not the clutches. I hope. Will the car run with the TCU disconnected?

[vkykam]

If there's no power to the duty solenoid C, the car will run 50/50 split all day long. I know this from experience. :( In fact, I still have the solenoid with the wire to it "fallen off".

I would doubt the TPS as the cause of it, as there is at least 10% power going to the back at any given time.

If the car is on a hoist, the rear wheels do not spin at ALL?

VK


Originally posted by svx_commuter


Thanks and I was talking about the back end of the tranmission being the transfer case in the case of the SVX. Can't I call it a transfer case?

The transfer clucth is operated by duty solenoid "C" and the way I understand it if the power is off to solenoid "C" the car is supposed to be in AWD. Or am I missing something? I was planing on disconnecting the the wire to "C" from the TCU to check this out.

Clogged orifice where? Still in the transfer case? or in the hydraulic control valve unit? Is there any easy way to check for this and maybe a way to flush it out without removing the transfer case?

[svx_commuter]

The wheels will spin until you look straight at them. Then the resistance from your line of sight stops them. No, seriously, they do not spin for long and can be stopped with a touch.

You say the wire fell off. Isn't the wire and solenoid inside the transfer case? I guess your power light said the car had a fault?

Can you say what the car was like with the 50/50 split? Great traction but 12mpg?


Originally posted by vkykam
If there's no power to the duty solenoid C, the car will run 50/50 split all day long. I know this from experience. :( In fact, I still have the solenoid with the wire to it "fallen off".

I would doubt the TPS as the cause of it, as there is at least 10% power going to the back at any given time.

If the car is on a hoist, the rear wheels do not spin at ALL?

VK

[vkykam]

The wire was inside the transfer case. 3 or 4 hours labour, one solenoid, 7 liters of Castrol synthetic fluid (they dumped out my old tranny fluid, which was 3 month old Redline Synthetic! :mad:), exhaust gasket, and $550CDN later, it was fixed. They saved the old part for me, so now I have a $100 paperweight.

Someone need a Solenoid C? Slightly used? Only needs a quick solder job... :)

12mpg was about right. Mileage was HORRIBLE. And to top it off, it was just past Christmas, with snow on the ground. On dry, every time I made a turn the thing would bind. And on snow, every time I made a turn, just a slight throttle blip would cause the tail to swing out wildly.

Believe me, it's much more fun doing 4 wheel drifts on snow with the system working properly. Never had so much fun on snow with a car!

Back to your problem. If the rear wheels spin, that's good. It doesn't take much to stop any one of the wheels with the car on the hoist. And once the wheel's stopped, I don't recall seeing it spin up on its own unless one of the other wheel was affected. What happens with the hoist on the car, stop the rear wheels, then stop the front wheels? Does the rear wheels start to spin up?

VK

Originally posted by svx_commuter
The wheels will spin until you look straight at them. Then the resistance from your line of sight stops them. No, seriously, they do not spin for long and can be stopped with a touch.

You say the wire fell off. Isn't the wire and solenoid inside the transfer case? I guess your power light said the car had a fault?

Can you say what the car was like with the 50/50 split? Great traction but 12mpg?

[svx_commuter]

Originally posted by vkykam
If the rear wheels spin, that's good. It doesn't take much to stop any one of the wheels with the car on the hoist. And once the wheel's stopped, I don't recall seeing it spin up on its own unless one of the other wheel was affected. What happens with the hoist on the car, stop the rear wheels, then stop the front wheels? Does the rear wheels start to spin up?

VK



Well both the back wheels stop and they do not start again. I tried to stop the front wheels by braking. This did not get the rear wheels going. I also have a 97 OBS and I tried the same test. The OBS wheels will not stop, lots of power but no LS rear, so one in the rear or the front will stop. Applying a little brake pressure will get all four spinning. This also tells the computer there is a problem with the speed sensor and the ABS system. These clear after the car is driven.

When I picked up my car yesterday, the man said "No pressure in the rear section" He even tried it on the grass. Broke the front wheels loose but not pressure in the transfer section even under heavy acceleration. He managed to get the bottom and side of the car caked up with dirt and grass and left two wide grass-less patches in the lawn! BIG fat SVX tire WIDE grass-less patches!:D

He says there is an electric problem. So........ I am off to track that down. I figure I will check the voltage to "C" at the connector by the TCU. If the voltage never goes off I am going to disconnect the lead to "C".

You know? You just reminded me of something. Where does the car get the signal from to tell the transmission that it is in a turn? Your experience says that when the car is in a turn the rear wheel drive backs off. I think this is because of the LS rear end or is it the same in all Subaru's?

[vkykam]

There have been people disputing whether the ABS sensors come into play with the AWD, but from the service manual, there was a mention that the ABS sensors are used to sense a turn as well.

I somehow doubt that as well, because I've pulled the ABS fuse now for 6 months, with a busted RR ABS sensor, and even in tight turns now the transmission does not bind.

Maybe there's an inertia sensor somewhere in the ABS system? I don't really know, it's just a guess.

If you disconnect the solenoid C power wire, you should have 50/50 split all the time. If you do, I would assume that the AWD physical components are working, and it could be an electrical issue. If you don't have 50/50 after disconnecting the wire, I guess it would have to be a physical problem? I dunno, just a guess.

Eddy??

VK


Originally posted by svx_commuter

You know? You just reminded me of something. Where does the car get the signal from to tell the transmission that it is in a turn? Your experience says that when the car is in a turn the rear wheel drive backs off. I think this is because of the LS rear end or is it the same in all Subaru's?

[eddycat2000]

The ABS wheel sensors have absolutely nothing to do with the function of the AWD. AWD is determined by the differential readings between speed sensors 1 & 2. Both of which are taken from the transmission.

However, after having read up in my copy of Road & Track, I think there may be a relationship between the ABS wheel sensors and the passive AWS.:D :D

[vkykam]

Hey, I'm just quoting the information out of the genuine Subaru SVX repair manual. Like I said, I doubt that as well.

I guess Fuji must have gotten Cletus-san to write that particular section. :D

VK

Originally posted by eddycat2000
The ABS wheel sensors have absolutely nothing to do with the function of the AWD. AWD is determined by the differential readings between speed sensors 1 & 2. Both of which are taken from the transmission.

[eddycat2000]

Originally posted by vkykam
Hey, I'm just quoting the information out of the genuine Subaru SVX repair manual. Like I said, I doubt that as well.

I guess Fuji must have gotten Cletus-san to write that particular section. :D

VK



Please scan and upload that section. The only computers that I know of that network in the car are the TCU and the ECU. I'd very much like to see what the F they are talking about. Think about it, why would the abs system care if you were 50% AWD or 10% AWD? *Nothing* that occurs in the AWD system would remotely affect the ABS system, all it needs to see is wheel 'inactive'...when braking. In other words, if it sees 3 wheels spinning, and one not, and the speed is above the specified limits, it activates the ABS...regardless of whether you are AWD or 90% FWD. (That's a condensed version, don't ask for a detailed description please, not in the mood).

[svx_commuter]

Well I got the TCU out. It is really tight under the steering column. The connectors are hard to reach. Not enough wire length to get it away from the brake pedal. I stopped by Radio Shack and got some leads to use in the connector next to the wire, as it says it the service books. I just can't believe all the tests they have in the service manual envolving the connectors on the TCU. This not a user friendly place. And if that is the ECU in front of TCU!!!!!!! Test on that will not be easy either.

Tomorrow I'll find out.

[vkykam]

I'll try to borrow a digital camera and take a picture of that page.

I don't own a copy of the manual. The local library does, and I'll get a copy for you.

I'm not disputing what you are saying, in fact, I agree with you that the ABS should have nothing to do with the AWD. That's what the VSS is there for. I mean, some SVXes, and certainly a large number of Legacy's didn't have ABS and had AWD. However, I'm just regurgitating what the manual said.

I *believe* they were implying that the ABS sensors were used to sense different wheel speeds, and therefore traction, and in a turn where the wheel speeds are different, it can sense it, and put the car in 90/10 split to reduce the possibility of binding.

I know that in some cars the ABS sensors are used to detect wheel spin and engage the traction control system. My since totalled 95 Legacy L+ FWD comes to mind.

If someone has the manuals and a scanner (AreDub, where are YOU??), the page I'm referring to is in the tranmission section. I found it while looking up the Duty Solenoid C troubleshoot procedure, so it should be near there.

Back to the problem at hand, since you mentioned the VSS, could a busted VSS not trigger a code, still have the speedo working, and cause svx_commuter's car to not have AWD?

VK
Definitely no AWD expert. ;)


Originally posted by eddycat2000


Please scan and upload that section. The only computers that I know of that network in the car are the TCU and the ECU. I'd very much like to see what the F they are talking about. Think about it, why would the abs system care if you were 50% AWD or 10% AWD? *Nothing* that occurs in the AWD system would remotely affect the ABS system, all it needs to see is wheel 'inactive'...when braking. In other words, if it sees 3 wheels spinning, and one not, and the speed is above the specified limits, it activates the ABS...regardless of whether you are AWD or 90% FWD. (That's a condensed version, don't ask for a detailed description please, not in the mood).

[svx_commuter]

I checked out duty solenoid "C" at the TCU connector and the voltages are fine. It has 11.6Volts in P and N. At rest in R,D,3,2,1 it is .37Volts to 3.7Volts and it oscillates on the digital volt meter. When driving at 5 mph it is about 5V and in a tight turn, left or right about 5V also. In a fast stomp to the floor I was not sure, as it was beeping and it is hard to keep track of the decimal point on the digital. So I got the analog meter and the voltage goes to ZERO when I stomp on the accelerator from rest. The analog also shows and the oscillation when at rest and in gear.
The resistance is 14.4 Ohms.

Would you agree that this means the transfer passageways are plugged up?

[eddycat2000]

Originally posted by svx_commuter
Would you agree that this means the transfer passageways are plugged up?

No, but I'd agree that someone needs to pull off the extension housing and have a look at the transfer assy. The transfer solenoid lives there too, so you can check it at the same time. If the electrical looks good, and it does, (but that's from memory and the fact that I always had a select monitor to watch voltages and didn't have to rely on multimeters)...now it's time to look for a hard failure. You could just have a case of completely worn out clutches that have too much clearance to engage. Sometimes the simplest explanation *is* the answer.

[svx_commuter]

Originally posted by eddycat2000


Sometimes the simplest explanation *is* the answer.

Hay Ed! Thanks:)

I have two more thoughts. The tranny man did not check the line pressure up front so I am going to have that done. To make sure it is where it is supposed to be. Could it be low line pressure? The tech manual has a very lrage range of what is acceptable. Any thoughts on this?

What about connecting the line pressure port in the front with the one in the rear? You know, run a hose from the one to the other. Would this not by-pass any blockage and engage the clutch? If the clutch is good.

Also a comment. I was speaking with Pat at Level Ten. He says that the transfer valve was changed after 92 because the original was too weak. Have you ever heard of that?

[eddycat2000]

Originally posted by svx_commuter


Hay Ed! Thanks:)

I have two more thoughts. The tranny man did not check the line pressure up front so I am going to have that done. To make sure it is where it is supposed to be. Could it be low line pressure? The tech manual has a very lrage range of what is acceptable. Any thoughts on this?



If your line pressure were really low, then none of the clutches would engage and the car wouldn't move at all. Or it could drop enough due to a busted pump gasket (old paper type), that it would move, but be *very* sluggish. If you have a manual, it'll tell you which port to plug into with your pressure gauge to check transfer pressure.

I've heard that Level 10 replaces transfer solenoids with suposedly updated ones...but I don't recall any bulletins about an updated part. But I may have missed it, or forgotten it, that's nearly 10 years ago now.

[svx_commuter]

Dear Ed,

Thank you again for your help.
When the car was at the tranny shop, the rear end transfer clutch pressure was measured. It was zero.

Originally posted by svx_commuter


When I picked up my car yesterday(8-24-01), the man said "No pressure in the rear section" He even tried it on the grass. Broke the front wheels loose but not pressure in the transfer section even under heavy acceleration. He managed to get the bottom and side of the car caked up with dirt and grass and left two wide grass-less patches in the lawn! BIG fat SVX tire WIDE grass-less patches!:D :( :(

[svx_commuter]

So the rear wheel drive does work on my car and the transmission shops do not really want to work on it.:mad: So I decided to cut the wire at the TCU for solenoid "C". Maybe this will clear any blockage in the transfer section. It will be open all the time and should see higher pressure always since it will open at highway speeds. A cheap attempt at a fix this is. I will most likely wire in a switch. Then I could turn it on and off as Larry III has suggested. If it ever starts to work!:cool: