andrewe539

All makes perfect sense. The humming is very rare, like maybe ones every two weeks for about 5 seconds. Could I*t* hold vacuum most of the time even if a seal is slightly damaged?

Also I️ used a vacuum pump on all the lines and they held at 25 for 2 minutes. Tested both iwe’s and they held the same. I️ don’t think I️ have a check valve issue since I️ feel like I️ would head the noise from both sides. Anyways will probably change both to be safe.

Would a bad IWE cause the grinding I️ hear when switching in and out of 4L?

techrep

iTrader: (1)

I would try an IWE solenoid first if both IWE’s held vacuum like you said. If you have a vacuum problem.. the noise should go away while the wheel ends are engaged (in 4WD) unless you have a clogged vent line which would prevent the wheel ends from disengaging or partial disengagement.

andrewe539

Me and a guy a Work just went out to try to dig deeper into this. Vacuum tested Rachel IWE,check valves,hoses separately and together. everything held at 25 for 2 minutes. The vacuum box hissed when I disconnected the check valve so I️ know that’s working. Either there is an IWE with a small leak that only appears randomly or the solenoid is bad. However I️ don’t have any trouble switching to 4H so I️ don’t think it’s a solenoid. May try an overnight vacuum test on the whole system.

We we also tried to identify where the noise is coming from when I️ shift into 4L. Couldn’t really tell anything other than somewhere right around the engine, which could be any aspect of the 4wd system.

This is time when I️ got the shift delayed message I️ put I*t* in drive but didn’t hit the gas and back into neutral. No whining just a loud bang when everything locked in. Tried I*t* again but hit the gas while in drive and the whining came back and then the bang. A new thing I️ noticed was that the 4L light was still on when I️ had I*t* into 2wd for a few minutes.

gohip2000

To me it sounds just like the IWE. They can still hold pretty good pressure and be messed up. Mine did that and the is a plastic component in them that easily snaps if the half shafts aren't properly installed back into the hub before torquing down the axle nut. I had very similar symptoms and just bought aftermarket IWE for about $90 a piece and installed them my self. The problem was completely fixed. I'm almost positive its your IWE. I would tell the place that installed your leveling kit that your dealership diagnosed a screwed up IWE's and they should replace them for you since they incorrectly reinstalled the drive shafts. Offer small claims court if they don't want to fix what they screwed up.

andrewe539

Update: I just got done installing a new IWE on my driver side. The thing was completely destroyed. The gear was out of the house and the rubber housing had split in two. Unfortunately, like an idiot, I torqued the CV shaft stud to much and sheared it off. So I ended up replacing the CV shaft as well. Did about a 3 mile test drive and everything is working great as far as the IWE goes, no more rattle and no humming.

However I still seem to be having the same issue with my 4WD low. After I did my initial test drive I stoped and shifted into 4H and out of 4H twice and everything worked great. Even drove about 100 ft and no issues. I then shifted from 2WD to 4L and everything shifted perfect. Then I shifted from 4L to 2WD and I got the "Shift Delayed-Pull Forward message. So I put the truck from Neutral to Drive and tried to pull forward, couldn't go anywhere. Then came the whinning and banging. My dash said 4x4 Low for about 10 seconds and then went to 2WD.

So I tried it a second time. 2WD to 4L, I got the "Shift Delayed-Pull Forward" message. Only this time I went from neutral to drive and I was able to pul forward and if shifted into 4L fine. Then tried to shift from 4L back into 2WD and got the message again, so I went into drive and could not go anywhere. This time I did not hit the gas I just sat there to see if that made a difference. I did not hear any whinning but I still heard the bang. My dash stayed in 4L this time, after about 30 seconds I shut the truck off and turned it back on. Dash now said 2WD. So I guess I am just going to have to have the issue diagnosed.

I am not very experienced in transfer cases but I do have a few questions.
1. Could the CV shaft not be meshing properly with the IWE and that what the noise is and why the first IWE was toast? Reason I ask is because when this started happening I was able to shift into 4L but coming out of 4L is where the problem started, same thing here.

2. Could it be something electronic?