Awd traction. Gurus needed!!

[Stainbox12]

i mounted my car in 4 stands last day, to check if my 4 tires would spin, and only the two on the front would spin, the rear ones didn´t spin at all, my question is basic though, when i launch my car, it burns all four tires, and it feels, that it pulls pretty hard, i get no wheelhop or anything like that. can someone tell me whats wrong or what should i check?


Thanks in Advance.

 

[FastGS-T]

4wd is when all wheels spin equally. AWD is smarter and different wheels move according to the load present (roughly). If Im right nothing is wrong.

 

[Stainbox12]

So that means, that if the car, is in 4 jacks, the rear wheels should not spin. but when i launch, it actually gets the AWD traction? WTF. Im confused, because ive heard people standing the car in 4 jacks, and all wheels spin.

 

[imasturb8onurv8]

You could try getting in some wet grass or something and gassing it and see if all 4 pull I mean there you have a little bit of load...

 

[Stainbox12]

I did. and all 4 wheels work. But im just suspicious for the fact, that when the car is standing in 4 jacks, just the front ones would spin.

 

[KVGSX]

this is just my asumption here but theres a differential in the transfer case and the way they work is they distribute power to the wheels with less traction. So i'd come to asume that its diverting the power to the front wheels cause with just the weight of the axles being the load theres less load on the front drive shafts then there is on the entire rear assembly. But when the car is on the ground the motor and everything adds extra load to the front end and kinda evens things out? all i know for sure s thatthe differential won't always distribute full power to front and rear.

sounds reasonable to me but again i'm just throwing out an idea.

 

[i1nk83]

Try turning the rear wheels, and see if all 4 wheels spin. You could possibly have destroyed your viscious coupler of the center diff. The front diff in our tranny's is an open diff, so it kind of makes sense for only the front to turn... I think

 

[Marc91GSX]

Ok I am really confuesd here. What are you trying to tell us? Do the rear wheels turn at all when there is no weight on them? If not then take off your e-brake. Unless your calipers are locked up then that is only thing that ( that you would not notice when driving your car) will cause your rear wheels to lock up .

 

[DragSourceTsi]

It takes a bit of a load to get your VC locked up. Just sticking your car up in the air and turning the front wheels won't make the back ones turn.

 

[Marc91GSX]

4wd is when all wheels spin equally. AWD is smarter and different wheels move according to the load present (roughly). If Im right nothing is wrong.

4WD and AWD are the same thing, It simply means that all four wheels receive power. The difference between smart track and a normal 4wd system is the way and time that the power is distrubitued to all four wheels. I have 5 4wd vehicles and the only difference between the 4wd system is the way the 4wd is engaged.

1) manually operated transfercase with a 50/50 split (89 Amigo)
2) Push button operated transfer case with a 50/50 split (02 F250)
3) viscous operated transfer case ( 00 Bravada)
4) viscous operated centerdifferential with a transfer case attached (eclipse X2)


Basicly they are all functioning with the same premise, to distribute the power to all four wheels and improve traction.

I guess to sum it up our cars are full time 4wd instead of part time 4wd. We also have a one speed transfercase instead of multiple range t-case.

 

[slugsgomoo]

on four stands, your rear tires should spin, and one of the fronts should spin (front is non-LSD). If you stop the front wheel that is spinning (careful!) it should allow the other side to start.

I have never heard of a dsm that is in the air only spinning the front two when it's in gear, assuming it's not FWD. Something isn't right, IMO

For what it's worth, I was doing this last week to my galant to flush the gearbox, and the rear, and front left DEFINITELY spin all at once. The right spun when I stopped the LF from spinning.

 

[DragSourceTsi]

I guess I ASSumed the car wasn't running when he did this. IF the car was off and he was spinning by hand the VC wouldn't lock up therefor nothing would go to the rear wheels.

 

[Stainbox12]

AS i said, they dont spin in the air, but in the ground i can feel the AWD traction. As a matter of fact, all 4 tires burn. no Wheelspin at all. If there´s something wrong i can´t figure it out.

 

[silvah_gsx]

Nothing's wrong...these AWD systems are based off of FWD, and on top of that you've got all this extra drag on the rears from the T-case and driveshaft--by hand there isn't enough strength to spin the rears, but by engine (or Schwartzenegger) there will be.

 

[DragSourceTsi]

It's about RPM you just can't spin it fast enough to lock up the VC.