So I had bilsteins and new tires put on a couple of weeks ago. I had the shop set them to 1.75 and I put 295/70/18s on the truck. Everything looked perfect. I went on vacation so I did not drive it for a week and when I got back and went to town there was a whining noise that sounded like wore out mud tires coming from the front end. I brought it back to the shop and looked at it and said that it was my vacuum system for the 4x4 and gave me all these scenarios. I brought it home and looked at it myself and noticed that the vacuum hose was pinched down by one of the bolts for the top of the strut. I did not touch it and brought it back the next day. They said oh yes that is on us. So they replaced the actuator and the vacuum hoses. All good driving it home....drove it a couple of days later and it was doing it again so I pulled into a driveway and backed out to go back home and the noise went away. So I turned around again and went to run my errand. When I left the store, it was doing it again so I pulled into another parking lot and put it in reverse for about 10 yards and then went forward and it never made the noise again all the way home. Today I put it in 4 high and drove a little ways and all good, then switched back to 2wd and went down the road and it was making the noise again. I put it in reverse for about 10 yard and it went away. My question is, are we looking at an installation error or could it be the something else. I am going to bring it back on Monday but just wondering if there is some troubleshooting I can do myself.

 

The other side could have gotten ruined also depending on how the vacuum played out while that line was pinched. I'd thoroughly check that hose for any kind of cracks or holes. Especially around the area that it was pinched.

Could also be an installation error if they had to pull the half shafts out of the IWEs.

 

They replaced the whole hose assembly. While the hose was pinched, it made the noise the whole time. Now its just sometimes. Being that when I stop and go in reverse, maybe it allows the vacuum to catch up and hold.

 

Or backing up unbinds the bad IWE so that it can fully retract.

Sounds like you have a leak somewhere. IWE (the one they didn't replace assuming they reinstalled the new IWE correctly). Or just a coincidence that your check valve is now giving you issues.

 

Yeah, i'd say there was a pinch leak too, i've seen people have this intermittently when their pipes only open the crack under certain conditions, like wheels turned one way or the other. I'd have it under pressure (2H engine on) and go round poking at all the pipes on both sides, wiggle them etc.

 

So they replaced the actuator on the side that was pinched and the whole hose assembly to both sides. They did not replace the solenoid or check valve. So it’s one of three......bad install on the actuator, have a leak at one of the connections, or bad check valve. It’s still just the passenger side that’s grinding. I put it in 4wd several times today and when I switch back to 2wd it does it until I stop and go in reverse for a few feet then go forward. I did notice that it does it in reverse after switching back to 2wd and then when I go forward it stops. I’m leaning bad install and it’s not lined up just right and it’s hanging up once the vacuum is started. Bringing it back tomorrow to the guys that screwed it up and give them one more chance. If they can’t get it right, I might need some help.

 

Make sure that they know to put some vacuum (not a lot as it doesn't take much to get it to move and you can ruin them that way also) on the IWE before they tighten the nut on the shaft. This way they won't have to worry if the gears are meshed or not. If they tighten it without vacuum and they are not meshed, they will ruin the IWE. Usually, not always, the tell tale sign is they would have heard a pop when tightening the nut down.

 

Thanks Blue. They called me back today and they heard a different noise when its in 4wd there is a air type sound coming from the transfer case when driving. It ramps up when on the gas and ramps down when you let off. I never noticed but when I use 4wd I am not at a traveling speed. I made it make the whining, mud tire type noise today when switching from 4wd back to 2wd. I went in reverse and it went away. He is telling me since I put the bilsteins on, it is putting the differential in a bind and he thinks it is a bad bearing. Its just making noise now since the shafts are on different angles.

Here is my view now. The whining noise was constant until they changed the vacuum line that was pinched. Now its just when put into 4wd and back to 2wd until I go in reverse. I could not make him understand that and he kept mentioning bearing. The air noise in 4wd traveling speed is new to me. I am going to pick my truck up and bring it home and decide if I will have them do any further work on the truck. They did a good job on the install and the truck rides great but they messed up the vacuum hose on the install and I am discouraged. I just do not have the time to do this myself.