awd vr4 only fwd

[Bmxr152]

Okay so i was doing my front control arms and sway bar links today and noticed when i spun the front tires in gear (with the rears on the ground) they did not lock up like normal. So i go under the the car and spin the front tires and dont see any movement on the driveshaft. This can explain why my car felt so loose in the snow recently.

I have a welded center diff and VCE on my jacks stage 2.1 transmssion. So im guessing the only thing that it could be is a stripped output shaft to the transfer case or stripped splines on the input to the transfer case. I was wondering how possible that could be. I have not done any launches with this transmission yet and i know when a month or so ago it worked fine. I didnt ever hear any weird noises or anything like that. I did however do some snow drifting and maybie that was to much stress on the splines. If anyone has any input or suggestions that would be great. Im going to look at it this weekend and see whats up.

 

[e85_4g63]

Your best bet is to put the car on a lift, put it in first gear and see if all 4 tires spin with the motor running and clutch engaged..

 

[jtmcinder]

The center VC is between the input and the rear. If the center diff is blown, the car is RWD directly via the VC. If the transfer case is blown (or the input to it is stripped), then the car is FWD indirectly via the VC and center diff. If the front diff is blown, the car is again RWD indirectly via the VC and center diff.

If you have a welded center, my money is on the front diff. But a diagnosis of this sort, across the internet, is probably worth what you paid for it.

edit: crud. he wrote VCE, not VC. ignore this post.

 

[RvlutionMtrsprt]

What exactly do you think the VCE is for? It turns an AWD car into FWD, generally for dyno tuning purposes. I could be wrong but I've never seen a VCE used for anything other than dyno'ing an AWD car someplace that only has a 2wd dyno. Were you using is as a substitute for welding? A proper diagnosis with all 4 off the ground is in order as suggested above. If you were using that combo of welded center and VCE to run in AWD I'm curious why you chose to run it like that??

 

[donniekak]

It's because you have an open front diff. When you spin one front, the rears can't move, because they are on the ground, so the other front tire spins the opposite direction.

 

[pauleyman]

I second the front diff. Normal operation.

 

[donniekak]

What exactly do you think the VCE is for? It turns an AWD car into FWD, generally for dyno tuning purposes. I could be wrong but I've never seen a VCE used for anything other than dyno'ing an AWD car someplace that only has a 2wd dyno.

He has a welded center diff. What a welded center, and/or vce do is lock the differential between the front, and rear. This lets you dyno your car fwd by removing the t case, or doing donuts in rwd by removing the front axles, and plugging the trans with cups.

 

[Bmxr152]

Yes the vce can be used to make your car fwd or rwd only but, only if you remove the axles. It makes it so you dont blow out the factory viscous coupler. Ive had it since the trans was new and i had awd for about 6 months until around when i was messing around in the snow.

So if i blew the front diff the car would still drive normal? I drives and shifts fine with no abnormal noises. well when i pull the transfercase this weekend we will see. i have a spare trans and xfer case so i guess i could put something together but its just weird how it just happened. I used to launch the crap out of my old 1g and never had this happen. You think the welded center diff would be causing alot of drivetrain stress?

It's because you have an open front diff. When you spin one front, the rears can't move, because they are on the ground, so the other front tire spins the opposite direction.

well it used to stop after a 1/8th of a turn or so and i could hear the driveshaft shock. I just locked the e brake and let out the clutch slowly in the ice/snow and it felt like just the front tires were spinning.

 

[RvlutionMtrsprt]

I get the FWD/RWD operations with a VCE but I don't understand why it would be used when running AWD for a prolonged period of time. A quick trip to the jack stands will uncover what's broken. Can you explain the reasoning for running the VCE in AWD mode? Were you constantly eating up viscous couplers and got sick of it so you just tried it out? Is there some advantage in f/r power distribution? I'm not trying to harp on you at all so I hope that's not how I'm coming off. I'm really just curious in case I run across a viscous coupler problem in the future since it's probably the weak link in my driveline (Quaife front, 4 spider, 4 bolt LSD rear).

 

[Bmxr152]

There is no reason to keep it in or take it out besides pulling the 5th gear cover. It just came with the transmission so i keep it in and also everyone around here only has 2wd dynos. So i just keep it in so all i have to do it put in my dummy front axles. Theres nothing wrong with keeping it in and ive never eaten a viscous coupler but if i put my dummy axles in with the factory coupler it would.

 

[RvlutionMtrsprt]

So basically just for convenience? It's just that most of the instances where I've read about people leaving it in for AWD operation lead to parts breaking.

 

[Bmxr152]

Just wondering how a vce would cause that with a welded diff. I was under the impression the welded diff does the same thing as a vce.

Anyways on a side note i did the front diff test where you jack up one side and spin the tire. I did it on both sides and both locked up at about an 1/8th turn. Jacked the front two up and the turn in opposite directions. So im guessing the front diff is ok and just a output to xfer or input to xfer problem. Well i hope at least because that would be easier.

 

[donniekak]

I get the FWD/RWD operations with a VCE but I don't understand why it would be used when running AWD for a prolonged period of time. A quick trip to the jack stands will uncover what's broken. Can you explain the reasoning for running the VCE in AWD mode? Were you constantly eating up viscous couplers and got sick of it so you just tried it out? Is there some advantage in f/r power distribution? I'm not trying to harp on you at all so I hope that's not how I'm coming off. I'm really just curious in case I run across a viscous coupler problem in the future since it's probably the weak link in my driveline (Quaife front, 4 spider, 4 bolt LSD rear).

He has a welded diff. A vc would never do anything anyway. They are removed to cut down on rotational weight in the trans, and replaced with the VCe to keep the ball in place that keeps the output shaft in place.

Just wondering how a vce would cause that with a welded diff. I was under the impression the welded diff does the same thing as a vce.

Anyways on a side note i did the front diff test where you jack up one side and spin the tire. I did it on both sides and both locked up at about an 1/8th turn. Jacked the front two up and the turn in opposite directions. So im guessing the front diff is ok and just a output to xfer or input to xfer problem. Well i hope at least because that would be easier.

Because with only 1 side jacked up, the other front tire can't spin backward, and the rear diff has an LSD so it won't spin just 1 tire. With both fronts off the ground the open front diff is free to spin backward. With 1 side jacked up, one side of the open front is stopped by the ground, the center is locked, and the rear has an LSD.

 

[Bmxr152]

Because with only 1 side jacked up, the other front tire can't spin backward, and the rear diff has an LSD so it won't spin just 1 tire. With both fronts off the ground the open front diff is free to spin backward. With 1 side jacked up, one side of the open front is stopped by the ground, the center is locked, and the rear has an LSD.

okay i was just read a past post that jtmcinder wrote saying if you jack up one side and the tire spins freely in the front then it would be a bad center diff or bad front diff.

 

[donniekak]

Your car is not displaying anything to indicate a problem.

okay i was just read a past post that jtmcinder wrote saying if you jack up one side and the tire spins freely in the front then it would be a bad center diff or bad front diff.

Yes, but you jacked up one side and it didn't spin. Your tires only spin with the whole front of the car jacked up. Unless you install a front LSD it will continue to do this.

 

[swifteagle]

Dident the vr4's have a selectable tcase?

 

[Bmxr152]

Your car is not displaying anything to indicate a problem.



Yes, but you jacked up one side and it didn't spin. Your tires only spin with the whole front of the car jacked up. Unless you install a front LSD it will continue to do this.

My tires used to lock up when both fronts were up and both rears were on the ground. Also i can lock the e brake and spin ONLY the front tires. before it would not move or spin any tires till i released the e brake. So it is showing a problem, thats not normal operation. also if i drop the clutch in dirt only the fronts spin. also when i get underneath the car and spin the front tires the driveshaft does not move when the car is in gear.

On a side not only older JDM galants had a switchable transfercase.

I'm not trying to argue or anthing, just trying to eliminate possible problems. Im leaning towards transfercase input out splines as my old transfercase splines were really worn when i threw my newer used one on like 10k ago.

 

[jtmcinder]

Now that I've decided to read more carefully, I, too, lean towards transfer case or something else between the center spool and rear wheels. When you launch a car with a center spool, a very large proportion of the torque ends up being used by the rear wheels (due to weight transfer). I can see it being 90% with good grip, lots of power, and a great launch. I do not believe that the transfer case was designed to take that much.

The only thing that makes me hesitate with this guess is that the OP said that the car was feeling loose on snow. If the word "loose" was being used in the typical way, that doesn't fit a blown driveline to the rear at all. FWDs push; they aren't loose. If it really was feeling loose, then we're back to a blown front diff.

With the car in gear, lift one front wheel and turn it while someone has their hand on the transfer case. If the wheel turns easily and very little or no vibration is felt in the transfer case, then it's probably the front diff. If the wheel isn't that easy to turn and/or a grinding is felt in the transfer case when you do this, then it's probably something between the center and the rear, such as the splines on the input shaft to the transfer case. But, in any event, if you can turn one front wheel with the others on the ground and the car in gear, you will be tearing the car apart to fix it, so a complete diagnosis right now isn't very important.

 

[donniekak]

Now that I've decided to read more carefully, I, too, lean towards transfer case or something else between the center spool and rear wheels. When you launch a car with a center spool, a very large proportion of the torque ends up being used by the rear wheels (due to weight transfer). I can see it being 90% with good grip, lots of power, and a great launch. I do not believe that the transfer case was designed to take that much.

The only thing that makes me hesitate with this guess is that the OP said that the car was feeling loose on snow. If the word "loose" was being used in the typical way, that doesn't fit a blown driveline to the rear at all. FWDs push; they aren't loose. If it really was feeling loose, then we're back to a blown front diff.

With the car in gear, lift one front wheel and turn it while someone has their hand on the transfer case. If the wheel turns easily and very little or no vibration is felt in the transfer case, then it's probably the front diff. If the wheel isn't that easy to turn and/or a grinding is felt in the transfer case when you do this, then it's probably something between the center and the rear, such as the splines on the input shaft to the transfer case. But, in any event, if you can turn one front wheel with the others on the ground and the car in gear, you will be tearing the car apart to fix it, so a complete diagnosis right now isn't very important.

With a welded center diff, if he only jacks up one front tire, it should not be able to rotate. And, if he tries really hard to force it, it can cause the car to drive off the jackstand. If he can turn the wheel, it does point to a front diff, or output shaft/t case issue.

 

[HIGHPSI4]

Dident the vr4's have a selectable tcase?

The EVO I had the switchable trans/tcase.

 

[jtmcinder]

With a welded center diff, if he only jacks up one front tire, it should not be able to rotate. And, if he tries really hard to force it, it can cause the car to drive off the jackstand. If he can turn the wheel, it does point to a front diff, or output shaft/t case issue.

If your front diff is OK and your center spool is still intact, but the transfer case is blown, then what stops you from being able to rotate a lifted front wheel is transmission and engine.

 

[donniekak]

If your front diff is OK and your center spool is still intact, but the transfer case is blown, then what stops you from being able to rotate a lifted front wheel is transmission and engine.

If the tcase or output shaft is blown when you rotate the front tire, the other cant spin backward, so the motion goes to spinning the center diff case, which spins the output shaft. If the output shaft is broke, or transfer case stripped, the wheel can spin freely, as the output shaft has no load on it. Why would you test the differentials with the trans in gear? That keeps the center diff housing from rotating.

 

[jtmcinder]

Exactly. That's one of the ways to discriminate between a blown front diff and a blown transfer case when you have a spool. If turning a front (with the other three on the ground) is difficult because you're trying to turn the engine, then the front is fine. If you can turn a front without difficulty (with three others on the ground and in gear), then it's the front that's blown.