How to know if a transfer case is bad???

Ok, found a nice 97 Legacy GT wagon automatic, its really cheap because he thinks the transfer case is bad.. He said it still drives but wobbles in the front. How do can you tell for sure that the something is messed up?

He said something about removing a fuse to find out that the front wheels weren't spinning or something crazy like that..

Some help on this subject would be great

TIA!

^^ that's what I thought! but I was afraid to say it; thanks for confirming it rmb

Yeah. My Jeep has a transfer case, but my Subaru does not.

Google the difference between 4WD and AWD.

Yeah. My Jeep has a transfer case, but my Subaru does not.

 

Google the difference between 4WD and AWD.

Has nothing to do with 4WD vs AWD, and everything to do with the boxer layout.

Has nothing to do with 4WD vs AWD, and everything to do with the boxer layout.

Nothing in front of the flywheel has anything to do with the drivetrain, so the boxer has nothing to do with AWD, 4WD, a transfer case or anything else pertaining to this discussion. As far as the drivetrains are concerned, the H4 in my Subaru is no different than the I6 in my Jeep.

4WD has a transfer case that can either engage only the rear axle or both the front and rear axles.

AWD has a center differential that engages both the front and rear axles at all times.

Nothing in front of the flywheel has anything to do with the drivetrain, so the boxer has nothing to do with AWD, 4WD, a transfer case or anything else pertaining to this discussion. As far as the drivetrains are concerned, the H4 in my Subaru is no different than the I6 in my Jeep.

 

4WD has a transfer case that can either engage only the rear axle or both the front and rear axles.

 

AWD has a center differential that engages both the front and rear axles at all times.

The fact that the boxer is not transversely mounted has nothing to do with whether a transfer case is required??? - might be tough to install a center differential on your I6, so I'm not sure what you mean when you say it's "no different"

To the OP, it's not good to buy a car off some one who has no idea what he's talking about, but seems to have self-diagnosed the problem. More importantly, it's not good to buy a car off of the aforementioned who has tried to "fix" the issue himself by doing things like installing the FWD fuse with out knowing why. What else has he diagnosed himself and tried to fix?

OT: Is the car truly FWD when the fuse is in or does it maintain a mechanical 90/10, but no greater to-the-rear bias?

" the H4 in my Subaru is no different than the I6 in my Jeep."

 

QUOTE]

 

Incorrect.

The AWD in a Subaru uses a trans axle in the front that splits the power between the front and rear wheels by means of a second pinion gear out the back of the case. There's no front drive shaft as you would find in a vehicle using a true transfer case.

Unless Jeep has moved to using a trans axle,the chances of the Jeep transfer case being the same as that found in a Subaru are nil.

 

cheers.

 

I'm 99% positive it's only FWD at that point. that's why it's not recommended because it's bad for that center diff. our cars are designed to be in some form of an awd at all times, whether it be 90-10 split or 50-50. If you put that fuse in, you better know what you're doing, and not drive for a while if you need it in an emergency. unfortunately, the OP's car that he wants to buy seems to have had that in for god know's how long, and that's a problem. pop the fuse and take it for a test drive if you can

The fact that the boxer is not transversely mounted has nothing to do with whether a transfer case is required??? - might be tough to install a center differential on your I6, so I'm not sure what you mean when you say it's "no different"

Both the Subaru H4 and the Jeep I6 are longitudinally mounted. A transfer case is not required in the Subaru because it has a center diff. And the Jeep I6 could easily use a center diff - in fact, they do on the full time 4WD Grand Cherokees.

Incorrect.

The AWD in a Subaru uses a trans axle in the front that splits the power between the front and rear wheels by means of a second pinion gear out the back of the case. There's no front drive shaft as you would find in a vehicle using a true transfer case.

Unless Jeep has moved to using a trans axle,the chances of the Jeep transfer case being the same as that found in a Subaru are nil.

 

cheers.

Who said the Jeep was the same as the Subaru? I used the Jeep as an example of a vehicle that has a transfer case, saying its different than the Subaru which has no transfer case.

Before anyone else wants to argue this, I'd suggest you spend some time and research how AWD and 4WD systems work.

From a high-level perspective, both systems have a motor, trans, front and rear drive shafts, front and rear differentials, axles and hubs. The only real difference is that the Jeep has a transfer case after the trans and the Subaru has a center diff after the trans. If you want to get into more detail, all of the above mentioned components are separate on the Jeep but the trans, center diff, front driveshaft and front diff are all part of the transaxle in the Subaru.

Sorry about the misunderstanding, bud. I don’t know much about Jeeps, and thought you were making a blanket statement that 4WD was the same as AWD, that a transfer case in a 4WD is the same as the center diff in an AWD.

We’re all here to learn, and I shouldn’t have used the rolly-eyed smiley face before asking what you meant – my bad.

Sorry about the misunderstanding, bud. I don’t know much about Jeeps, and thought you were making a blanket statement that 4WD was the same as AWD, that a transfer case in a 4WD is the same as the center diff in an AWD.

 

We’re all here to learn, and I shouldn’t have used the rolly-eyed smiley face before asking what you meant – my bad.

No worries, especially about the rolly-eyed smiley. Considering the double flip-off smiley that gets used on a lot of the other forums I use, that rolly-eyed smiley is child's play in the smiley world.

A lot of incorrect information gets passed around on all forums, so I generally try to correct it when I see it.

I apologize to the OP for keeping this OT - hopefully we've answered your question already - but what about the I6 precludes the use of a center diff. I'm still learning, but can't picture a longituduinally-mounted engine and transfer case arrangement.

The motor has nothing to do with it, but ALL 4WD and AWD systems have the motor mounted longitudinally. I don't want to search and post links because I'm at work, but do some googling and find out how a differential works, how a transfer case works, how 4WD works and how AWD works.

4WD uses a transfer case that accepts power from the transmission and sends power out to front and rear driveshafts. It also allows the operator to select 2H, 4H and 4L. When 4H and 4L is engaged, the front and rear drive shafts turn at the same speed at all times.

AWD uses a center differential that accepts power from the transmission and sends power out to front and rear driveshafts. It always has both driveshafts engaged, but it allows them to spin at different speeds.

Full Time 4WD is a combination of the two and uses a transfer case with 4H and 4L as well as a center differential. Its basically AWD with the addition of 4L.

I understand how they work, but thanks anyway for the info.

Are you sure about ALL AWD and 4WD being longitudinally mounted? I'm sure that's wrong

Are

The motor has nothing to do with it, but ALL 4WD and AWD systems have the motor mounted longitudinally. I don't want to search and post links because I'm at work, but do some googling and find out how a differential works, how a transfer case works, how 4WD works and how AWD works.

 

4WD uses a transfer case that accepts power from the transmission and sends power out to front and rear driveshafts. It also allows the operator to select 2H, 4H and 4L. When 4H and 4L is engaged, the front and rear drive shafts turn at the same speed at all times.

 

AWD uses a center differential that accepts power from the transmission and sends power out to front and rear driveshafts. It always has both driveshafts engaged, but it allows them to spin at different speeds.

 

Full Time 4WD is a combination of the two and uses a transfer case with 4H and 4L as well as a center differential. Its basically AWD with the addition of 4L.

I understand how they work, but thanks anyway for the info.

 

Are you sure about ALL AWD and 4WD being longitudinally mounted? I'm sure that's wrong

Are

He is wrong.

Look at the Evo,,, The Toyota Matrix AWD, and the like...

4WD is selectable 4 wheel drive. During normal operation the vehicle only powers two wheels. The user can select 4WD for low traction duty. You don't need a transfer case in a 4WD vehicle although this design is most commonly built using a transfer case.

AWD means the car powers all 4 wheels during normal operation, and most have a center differential. Some AWD vehicles have transfer cases, like the Chrysler 300C AWD. Some don't, like the Subaru Legacy.

A longitudinally mounted engine makes AWD and 4WD easier to design. The Subaru design has no transfer case. Instead, picture a regular FWD car with a longitudinally mounted engine. The front CV shafts run straight into the transmission, which houses the front differential. There is also a regular output yolk on the rear of the transmission to power a driveshaft to the rear differential. It's essentially a cross between a longitudinally mounted FWD and RWD transmission. There is no center front drive shaft in this system.

A transversely mounted AWD platform (Which is sadly becoming more and more popular with AWD cars like the Toyota Matrix and the Mitsubishi EVO) is pretty much a regular transaxle with a set of spider gears that run power off the front differential to a rear output shaft, where a center driveshaft carries the power to a rear differential.

I understand how they work, but thanks anyway for the info.

 

Are you sure about ALL AWD and 4WD being longitudinally mounted? I'm sure that's wrong

Are

Just to be sure we're talking about the same thing... A longitudinally mounted motor is like a V8 in an old muscle car. A transverse mounted motor is like an I4 in a Civic. To get power to the rear wheels, the flywheel on the motor has to be at the 'back' of the motor, against the firewall. ALL RWD, AWD and 4WD vehicles have the motor mounted longitudinally. ALL FWD vehicles have the motor mounted transversely.

edit: Just saw Platinum's post above mine, and I was unaware that those transversely mounted AWD vehicles existed. I was wrong, so change "ALL" to "MOST" in my posts.

Just to be sure we're talking about the same thing... A longitudinally mounted motor is like a V8 in an old muscle car. A transverse mounted motor is like an I4 in a Civic. To get power to the rear wheels, the flywheel on the motor has to be at the 'back' of the motor, against the firewall. ALL RWD, AWD and 4WD vehicles have the motor mounted longitudinally. ALL FWD vehicles have the motor mounted transversely.

 

 

edit: Just saw Platinum's post above mine, and I was unaware that those transversely mounted AWD vehicles existed. I was wrong, so change "ALL" to "MOST" in my posts.

Looks like some one's only right "MOST" of the time

Just to be sure we're talking about the same thing... A longitudinally mounted motor is like a V8 in an old muscle car. A transverse mounted motor is like an I4 in a Civic. To get power to the rear wheels, the flywheel on the motor has to be at the 'back' of the motor, against the firewall. ALL RWD, AWD and 4WD vehicles have the motor mounted longitudinally. ALL FWD vehicles have the motor mounted transversely.

 

 

edit: Just saw Platinum's post above mine, and I was unaware that those transversely mounted AWD vehicles existed. I was wrong, so change "ALL" to "MOST" in my posts.

The Oldsmobile Toronado is a prime example of a longitudinally mounted FWD car, and it has a big block V8 engine with a chain driven transmission. Another good example is the Dodge Intrepid with a similar transmission layout as my first gen 2WD Legacy. Speaking of the FWD first gen Legacy, it is also a longitudinally mounted FWD car. The Subaru FWD 4EAT transmission is virtually identical to the AWD 4EAT with the exception of the center diff, the rear output shaft, the valve body, and the electronics. Add the center diff, the output yolk, transfer duty solenoid, and the computer of an AWD and its the same thing with the same gear ratios and everything.

A prime example of an AWD car with a transversely mounted engine is the Honda Civic AWD Wagon, the Mitsubishi Evolution, and the Toyota Matrix AWD.

If I wanted to get all technical, the Toyota MR2 is a prime example of a transversely mounted RWD car, but it is a rear engine platform so this is a bit of a stretch.

It is true that most FWD cars are transversely mounted. In my opinion, these cars handle like a sled on concrete. It is also true that most AWD (And virtually all front engine RWD cars) use longitudinally mounted engines. The recent trend of transversely mounted AWD cars is disgusting, since the geartrain for the rear output yolks is grossly underbuilt and weak looking. The Subaru AWD transmission pretty much involves two separate parts of the transmission to power the front and rear drivetrain, while cars like the EVO and Matrix AWD are pretty much stock 2WD transaxles with an added pair of gears attached to a rear output yolk as a total afterthought. The center diff is also offensively small. Except for the rear output yolk and a couple of pieces, the transmission is virtually identical to a FWD transaxle, which seems a bit wimpy to me. At least Subaru made their cars to be AWD, rather than some companies who make their transmissions to be FWD then make them AWD later to save a dime.

http://i111.photobucket.com/albums/n160/Lil_Shoaf/Subaru/P7140428.jpg

Here is a Subaru transmission. Note the dual front output yolks attached to the front differential. The entire front drivetrain with the exception of the CV shafts is mounted inside the transmission. The output for the rear driveshaft is located in it's normal spot behind the transmission. Note the center differential, which is able capable of altering the power ratio to the rear wheels. On early Subaru vehicles the power was usually 90% front, 10% rear unless the front wheels started slipping, in which case the transfer case would alter power up to 50%-50% front to rear in an attempt to regain traction. Newer systems are more complex and offer more control.

http://image.off-roadweb.com/f/9132014/0707or_07_z+1991_jeep_wrangler_yj_buildup+transmission_transfer_case.jpg

Here is a transmission with a separate transfer case. The transmission only has one output which leads into a transfer case. The transfer case has two outputs, one for a front driveshaft, and one for a rear driveshaft. Each driveshaft goes into a separate differential or axle at the front or rear of the vehicle, which transfers power to the wheels. The unit pictured has no center differential like the Subaru transmission. The power distribution front to rear is fixed at 50%-50%.

http://www.motorauthority.com/wp-content/uploads/Mitsubishi/EvoX/final/S_AWC_L.jpg

http://static.flickr.com/39/75406251_1252c97eff.jpg

Here is a transmission from a Mitsubishi Evolution. Note that the engine is transversely mounted and there is are dual output shafts for the front CV shafts, and one output shaft for a rear driveshaft. Note how puny the rear drivetrain is compared to the Subaru. It's almost insulting. In the lower image, the yellow box labeled "ACD" are the internals of the transmission with its overly long output shaft and puny geartrain. In case you haven't already figured it out, I hate the EVO's transversely mounted AWD design and anything that even looks like it.

Ok, I already said I was wrong to say "ALL" and should have said "MOST." What more do you guys want???

And thanks for posting the pictures; that's what I wanted to do yesterday but couldn't because I was at work.

Ok, I already said I was wrong to say "ALL" and should have said "MOST." What more do you guys want???

 

And thanks for posting the pictures; that's what I wanted to do yesterday but couldn't because I was at work.

Hey, no one's giving you a hard time. I'm the only one who made a silly, non-harsh comment to lighten things up. Plat has been putting out some good info, besides.