Is my AWD clutch pack working?

[johnceggleston]

I came across this by accident the other day and thought some of you might like to try it.

 

Find a hill, come to a stop, shift your A/T into 2 and start to slowly climb up the hill. Give it just enough gas to move forward. Then while moving forward, bump the gear selector from 2 to 3 and if your AWD is working, you should accelerate up the hill without changing the throtle.

 

When the gear selector is in 2, the computer / trans drives both front and rear axles all the time. This puts a much greater load on the engine. When you shift up to 3 the computer/trans only drives the rear axles if needed. This frees up a bunch of engine power which is all on the front wheels, and off you go.

 

 

EDIT: doubtful.

looks like my knowledge and reasoning is off. i need to do more reasearch.

 

 

John.

[Manarius]

My clutch pack was working just fine. Yesterday, I could get the rear wheels to engage anytime I felt like it.

[RallyKeith]

Sorry, but I think you're off. On the 4EAT transmissions that do not have the manual switch on the shifter, 2 acts like a manual mode. I keeps the car in 2nd gear no matter what. 3 on the shifter does not work this way, rather it is more of an overdrive cancel. Meaning in 3 it will use what ever gear it feels it needs, except 4th.

 

So, in your situation what you are really doing, is pulling out in second, and when you put the shifter up into 3 it's shifting back into 1st.

 

Sorry....

 

Keith

[Skip]

sorry John,

I believe the reason you picked up speed was

not the clutch pack disengaging

 

but

 

the TCU shifting the car into first gear.

 

In "2" the TCU locks the tranny in second gear,

 

used when low traction is prevalent and the lowered

gear ratio would cause tire spin.

 

You do not grace us with the year/car you used for this test

so I could be mistaken.

[PopsicleMud]

Also, doesn't the year of the transmission affect whether the TCU engages the clutch pack when you shift the lever to 2?

[johnceggleston]

sorry, 97 obw.

 

i just ASSUMED that when 2 was selected, it would use 1st or 2nd. i didn't know 2 was 2nd only.

 

i didn't try it but a couple of times and i didn't check the tach while doing it. so i'll have to try it in 1st and see what happens.

 

i guess i better edit the title and my first post.

[nipper]

HUH?

 

thats just silly

 

that makes no sense. If you want to know if your wad is working, just do what the rest of us do. Find a dirt lot or grass or someplace slick and nail the gas. Either you will take right off, or you should spin a front and rear wheel.

 

The other way is to put in the FWD fuse on a wet road and nail the gas, the front tires should spin. Do it again with out the AWD and you wont spin.

 

The ECU forces 50/50 in 1st and reverse. Also the TCU forces it at wide open throttle. Technically in the auto you always have awd (10/90 split minimum).

 

Also more wheels driving on the ground does not mean an increase in speed, unless the surface is slick (and in this test would have to be ice).

 

As far as engine power, this goes along with the gas mileage theories. Since everything is driven all the time, there is no increase or decrease in engine power. You have to physically dissconnect the rear wheels from the rear cv joints for that to work. And with computers, the engine would adjust anyway so you wouldnt see a differnce.

 

nipper