GEN 1 Nasty pop from driver's side front wheel area in four wheel drive (still)

I've had my right side axle replaced twice under warranty because it has broken - I'm extremely familiar with the sharp metallic TWANG of a ruined weekend. I'm still getting this sound when I'm in four wheel drive (not on pavement) and moderately turning to the left. You can physically feel it bind for a moment and it's loud enough that anyone around looks to see what just broke. This can't be normal.

I took it to the dealer for a couple routine things in addition to this. Dealer says everything appears fine, but agrees it shouldn't do that. Dealer wants to charge me $300 to go through and torque every bolt (mechanic thinks something is loose). I'm sitting at just under 50K miles (drivetrain warranty still active, in addition to an extended bumper to bumper). Uh, negative ghost rider. I told them no dice unless they come back with what is specifically wrong and we go from there. I'm not paying for their mechanic to monkey around for three hours. My opinion is that it's the IWE - and I've told them as much. They say the vaccum lines are fine (whoopee). So, they've agreed to dig some more, but I'm pretty positive they're going to try to find a way to charge me for something that, in my opinion, is drivetrain, no matter how you look at it. I mean, how can the front end binding/popping NOT be drivetrain? The front is stock other than mid-perch (done at dealer with assurance it wouldn't affect warranty).

Thoughts? Opinions on what's going on?

Iwe is pooched.

ntm said:

Iwe is pooched.

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That's what I think too - first thing I told them... now how do I convince THEM of that other than "the internet says..."

That's gotta be drivetrain, right?

Dane said:

That's what I think too - first thing I told them... now how do I convince THEM of that other than "the internet says..."

That's gotta be drivetrain, right?

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What happens with the IWE is it will get a small longitude crack in it. When the truck is on the lift with 4 wheel engaged, there's no load on the iwe. So it appears to be operational. If the mechanic was able to load the iwe, the crack would open and allow the gears to slip. When the iwe snaps back together, the system catches and causes the loud noise.

So, have you taken the tech for a ride to show him what is happening?

Or, tell him to take the three hours and pull apart the iwe and do a thorough inspection, or replacement. If it fixed the issue, he covers under warranty.

@Yukon Joe
www.runraptorrun.com

Yukon Joe said:

What happens with the IWE is it will get a small longitude crack in it. When the truck is on the lift with 4 wheel engaged, there's no load on the iwe. So it appears to be operational. If the mechanic was able to load the iwe, the crack would open and allow the gears to slip. When the iwe snaps back together, the system catches and causes the loud noise.

So, have you taken the tech for a ride to show him what is happening?

Or, tell him to take the three hours and pull apart the iwe and do a thorough inspection, or replacement. If it fixed the issue, he covers under warranty.

@Yukon Joe
Run Raptor Run | Great Lakes Raptor Excursions (GLRE)

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Great info, thank you. I didn't take him for a ride personally, but they did take it out and reproduce the noise - I also have it on video from a couple weeks back. So there's no disagreement that it's happening at least. I'll see where I can go armed with that info.

Dane said:

Great info, thank you. I didn't take him for a ride personally, but they did take it out and reproduce the noise - I also have it on video from a couple weeks back. So there's no disagreement that it's happening at least. I'll see where I can go armed with that info.

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Also, you can get enough wear on the iwe engagement surface on the outboard cv to do the same.

Well, went and took the tech for a ride and was able to demonstrate the noise. He's able to make it happen too. Replaced the IWEs (I don't know why both) and no joy, it's still happening. They're going to go through and torque every bolt - he thinks something is loose, loose being relative where stuff is torqued to ridiculous numbers.

Sorry that you still have the problem, but could you elaborate on the 'torqued to ridiculous numbers'

Oh, I forgot, have them check the front diff, it is likely locking up.
Or you could just have a loose pivot on the lower control arm.

PropDr said:

Sorry that you still have the problem, but could you elaborate on the 'torqued to ridiculous numbers'

Oh, I forgot, have them check the front diff, it is likely locking up.

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Oh, I just meant that the bolts in the front suspension are torqued to something like 400+ pounds if I remember right... so "loose" doesn't really mean it would appear/feel loose, but if something is supposed to be 450 ft lbs and it's 300, well, that's "loose".

Front diff locking up? I'll bite, what do we do about that if that is the case? It REALLY feels and sounds like the driver's side CV area.

Dane said:

Oh, I just meant that the bolts in the front suspension are torqued to something like 400+ pounds if I remember right... so "loose" doesn't really mean it would appear/feel loose, but if something is supposed to be 450 ft lbs and it's 300, well, that's "loose".

Front diff locking up? I'll bite, what do we do about that if that is the case? It REALLY feels and sounds like the driver's side CV area.

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Well, hat particular bolt is relying on clamping force, and therefore needs a high preload.
As to your problem: the diff is on the left, your noise is on the left; if the diff mounting bolts are loose it will shift under changing loads. If the diff is locking up it will cause the a windup and release in the shafts from the transfer case to the front hubs.
If you have a loose lower control arm pivot it will shift under front drive engagement. Two wheel drive the pivots try to move out; with the front wheels pulling the aft one will try to pull out, but the front one will try to push in, and that would make a bang...