AW4 Should it free wheel?

I finally got my AW4 shifting right but since I have never driven it shifting I'm not sure it is right yet. When driving down the street and letting off the throttle it doesn't freewheel like my other car. It has compression braking....right or not?

It as a little as long a you don't touch the brake.

Am I understanding that it should freewheel unless you touch the brake? Mine at the present does not freewheel at all. If I chop the throttle the drivetrain "clunks" from the engine braking.

tgregg said:

Am I understanding that it should freewheel unless you touch the brake? Mine at the present does not freewheel at all. If I chop the throttle the drivetrain "clunks" from the engine braking.

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No the other way around, there is engine braking until you touch the brake then the converter unlocks.

OK I got it. Thanks. Then it sounds like it is doing just what it is supposed to do. Having it shift through ALL the gears automatically sure improved my gas mileage....always a good thing.

Tgregg,

I have observed in my '90 that when in D, the tranny will freewheel when the throttle is 0%. I.E., coasting @ 40mph in D, RPMs will be at ~900 if I am off the gas.

However, if I shift to 3, or 1-2, then there will be compression braking when coasting and the engine speed will match wheel speed.

It sounds like your AW4 is behaving as if it's in engine braking mode all the time, and I do not believe that is normal. Definitely shouldn't buck back and forth when transitioning from decel to accel unless you are winding down from 3,000 RPM with the selector in 1-2 or 3.

You should get, to quote langer, "a little" drag when coasting in gear, but my AW4 seems to freewheel just like any other automatic.

Is your NSS working? Perhaps your AW4 thinks it is in position "3" all the time?

When the convertor is locked, stalled, or near stall, you have more coupling to the engine. When those conditions exist, the larger the difference in speeds between the engine and drivetrain, the more engine braking action you will encounter. So in order of increasing brake action it comes out like this (least)OD,D,3rd,2nd,1st(most).
The only time you loose engine coupling completely is if the engine stalls. Since the forward pump is driven off the engine, all the clutches/bands dissengage.

So, yes, contrary to most peoples belief, you can use an automatic for engine braking. It is just not as efficient a brake as a direct coupled clutch system.

I'm not sure I saw a definitive answer here. When cruising along at or above ~45mph, my TC is locked. However, if I lift my foot from the throttle, the TC unlocks until I put my foot back on the accelerator. Is this normal or should the TC stay locked until I touch the brake pedal? If the TC should stay locked upon lifting from the throttle, what is likely to be the cause of my problem. My AW4 shifts correctly otherwise and the lockup kicks in at about 42-43mph under light throttle application.

Thanks,
Dave

CantonXJ said:

I'm not sure I saw a definitive answer here. When cruising along at or above ~45mph, my TC is locked. However, if I lift my foot from the throttle, the TC unlocks until I put my foot back on the accelerator. Is this normal or should the TC stay locked until I touch the brake pedal? If the TC should stay locked upon lifting from the throttle, what is likely to be the cause of my problem. My AW4 shifts correctly otherwise and the lockup kicks in at about 42-43mph under light throttle application.

Thanks,
Dave

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If what you are descibing happens in D, then put your worries away. At 43-45mph the Trasmission is in OD, the TC is almost Stalled, and everybody is happy. When you lift, the TC drops below stall, and everybody is still happy. Well, every one except the guy behind the wheel.
I have found that my Jeep likes to see a constant speed with rpms above converter stall for a while before it actually locks the convertor.

CantonXJ said:

I'm not sure I saw a definitive answer here. When cruising along at or above ~45mph, my TC is locked. However, if I lift my foot from the throttle, the TC unlocks until I put my foot back on the accelerator. Is this normal or should the TC stay locked until I touch the brake pedal? If the TC should stay locked upon lifting from the throttle, what is likely to be the cause of my problem. My AW4 shifts correctly otherwise and the lockup kicks in at about 42-43mph under light throttle application.

Thanks,
Dave

Click to expand...

Mine locks at the same point. But won't unlock unless I let off the gas or give it lots of gas. So when I get to a hill and don't want to have to hammer the throttle to downshift I have to do a quick off then on to get it to unlock and pull up the hill.

It's annoying but I'm pretty sure it's because my gear ratio is taller than it should be.