4 Wheel Drive - Front end popping

[BSouders80]

With the cold weather and snow, I've used the 4 wheel drive more in the last week than I have in the last 2 years. When in 4H, I sometimes hear a popping noise coming from the front end. Sounds more like the passenger side as compared to the passenger side. Example: Had a 8' x 10' trailer behind my truck (empty - headed to cut a load of wood) and I had a slight hill to get up and over. Kicked in the 4 wheel drive from a stop and started after it, slow and steady. I started to slide so I got on it a little. We're talking like 10 mph. 4 wheel drive engaged fine and I got to where I needed to go. In the getting up the hill, I heard it pop a few times.

I plan to get it looked at, but would like input on where to start first. IWE's have not ever been replaced. Sitting at around 105K. Ball Joints, UCA's, Tie rod's are all good. I'd say maybe 5K on those. In my mind, front differential, CV shafts, IWE's, but what else?

Thanks.

Brian

 

[The Car Stereo Company]

rookie. you should know this by now. its either a vacuum leak or a bad axle.... or both.

 

[BSouders80]

Haha. Yeah I know. I don't think it's vacuum becuase it does go into 4wd without issue. I'll pull the CV's and check them out first. Just getting a little input on what I might not be thinking of. Realistically, it can only be a few things. Thanks man.

 

[MTF]

Transfer case is an electric actuator, the two IWE are vacuum.
When giving gas, vacuum decreases and what you're describing is noise when gas is applied.
So, somewhere you have a small leak, vacuum test is in order, just my two cents.
Otherwise IWE are damaged or at least on their way out (not enough plastic teeth left/worn down)

 

[ograptor]

The plastic tubing that Ford uses doesn't last very long in my experience.

 

[TomDirt]

They've been using those rubber IWE vacuum/vent lines since 2004. I'm sure the oldest ones have ALL worn out since new.

 

[Jhollowell]

I've been having a similar problem. If i engage 4x4 on a hill I'll get a pretty loud bang after a few feet. Sounds like its slamming into gear or something. Only does it if i engage 4x4 on a hill. if i engage on flat road and drive a little ways, i don't have any issues when getting to the steep parts. I should just suck it up and replace my IWE lines as well. Seems like an easy fix or at the least, good preventative maintenance.

 

[BSouders80]

Agreed. I'll probably start with the IWE's and vacuum lines as well. That is if nothing jumps out as being the culprit. I've considered the IWE delete, but my mileage already sucks running E85. I don't need anything else to pull that down more.

 

[pcs]

sometimes the center nut that holds the cv shaft to the hub behind the dust cap can back off. check the torque on it. as mentioned earlier what you are describing sounds like a iwe issue. as the engine revs, vacuum goes down which can cause the iwe to slightly disengage. going up hill while pulling a trailer adds extra load and with minimal gear teeth engagement due to vacuum lose could be the reason. i had a similar situation when pulling a trailer in some soft terrain. when i would get on the throttle, the hubs made a popping sound. when i let off the throttle and vacuum would go up, the iwe would try to re-engage and make a grinding sound.

 

[Gumby]

sometimes the center nut that holds the cv shaft to the hub behind the dust cap can back off. check the torque on it. as mentioned earlier what you are describing sounds like a iwe issue. as the engine revs, vacuum goes down which can cause the iwe to slightly disengage. going up hill while pulling a trailer adds extra load and with minimal gear teeth engagement due to vacuum lose could be the reason. i had a similar situation when pulling a trailer in some soft terrain. when i would get on the throttle, the hubs made a popping sound. when i let off the throttle and vacuum would go up, the iwe would try to re-engage and make a grinding sound.

This is not how the IWE works. Default is no vacuum and engaged. When you shut the truck off the hubs lock every time. if you have a Gross leak the hub will remain engaged and Will ware on the IWE. Mine Popped the other day coming in the hood.... going up the hill in the snow. why? I waited to late to activate the 4 wheel drive. the hubs will struggle to engage in this situation. It is like the transfer case works faster than the hub. that is my thought on it.