Need Help, Drivetrain Binding

[ajax33]

I have a 98 XLT 4.0L with AWD. when I put it into one of the drive gears, the engine bogs down, I hear a sort of ratcheting sound, then the engine dies. reverse seems to be fine. and I noticed that it isn't so noticeable in 4Low. I am thinking it is the TCase. Is there anything I can do to know for sure? Thanks for your help.

 

[joecrna]

This sounds like you are stuck in 4WD but lets make sure. Leave the selector in 4WD Auto. Turn the front wheels sharply to one side and drive forwards slowly. This will make the binding and noise worse if the front axle is stuck engaged. Also the turning circle will be much wider than expected.

 

[ajax33]

you don't understand, then engine dies when I put the X into one of the forward drive gears. I can not drive it.

 

[IZwack]

Get the wheels up in the air, put your foot on the brakes, start the vehicle, put the vehicle in Drive, and slowly let the brake out. Then have some one else listen for any noise. To stop the vehicle, just kill the engine (dont try to put the vehicle in Park unless you press on the brake first to stop the wheels from spinning).

What I'm thinking is that one of the axles might have grenaded.

 

[joecrna]

Quite possibly. With all four wheels in the air, at least one front and one rear wheel should spin. No matter what position the 4WD selector is in. Completely killing the engine in gear is almost certainly mechanical, not electrical. Tell us exactly what happens when you do this. We can go from there.

 

[joecrna]

Just had a thought. You say the engine stalls whenever it goes into one of the foreward gears. I think we're looking too far down the drive train. The torque converter should allow enough slip to keep the engine running. Just as when you are sitting at a light, in gear, with the brake applied. So the engine starts normally. No sounds or trouble in Park. Reverse, still everything is OK. No bog, stall, or noises and the truck moves? How about Neutral? Is everything still OK?

You then put it in drive or any foreward gear and it makes a ratcheting sound, then bogs and the engine stalls. Do I have this correct. We are going to need detailed specifics to try and diagnose this.

 

[ajax33]

Just had a thought. You say the engine stalls whenever it goes into one of the foreward gears. I think we're looking too far down the drive train. The torque converter should allow enough slip to keep the engine running. Just as when you are sitting at a light, in gear, with the brake applied. So the engine starts normally. No sounds or trouble in Park. Reverse, still everything is OK. No bog, stall, or noises and the truck moves? How about Neutral? Is everything still OK?

You then put it in drive or any foreward gear and it makes a ratcheting sound, then bogs and the engine stalls. Do I have this correct. We are going to need detailed specifics to try and diagnose this.

You are correct above. The truck is on stands. The front wheels will spin at first, then after just a short time, they stop spinning. Neutral is ok. I noticed the a clunk when I shift now into any gear other than park or into neutral. Then the engine dies. The engine continues to run though when put into reverse.

 

[gijoecam]

Indeed, I think we're looking at a transmission issue, not a t-case or driveline issue... Nothing in the driveline or from the transfer case back is going to cause the engine to stall.

-Joe

 

[joecrna]

I wouldn't think transmission itself either. We use trans brakes (1st and reverse both engaged) to hold at the starting line while applying power on our dragsters. The torque converter still supplies the slip to allow the engine to run. Though I don't know why Park and Nuetral are OK if it is the torque converter. Unless these are no load conditions on the converter output shaft. I think we need to here from Glacier.