I hate to keep posting after myself, but I can't say I'm getting a ton of replies Anywho.... After getting home this evening I poured over the vacuum system and messed with everything again. As far as I can tell

-IWE solenoid (replaced earlier this year): Checked
-Vacuum Check Valves: Checked
-Vacuum Lines: Checked
-Jacked up either side and started truck, IWE's disengage every time: Check
-Put truck under load (pressed gas pedal a bit) while jacked up in Park, hubs
stayed disengaged: Check
-Put hand Vacuum pump on either IWE and both disengaged: Check

Is it possible to lose all vacuum under load? Or have vacuum under load, but when you, say, let off the gas lose vacuum for a period of time?

Listened to the wheel bearings and could not hear anything grinding or binding or squealing... Pulled off the small cap on the ends of the hubs off and listened with an automotive stethoscope deal and still nothing. I would love to take the hubs/IWE's apart and physically inspect them but have no time for the truck to be down for an extended period of time anytime soon..

 

Yes the vacuum can be lost under load while the truck is driving. That IWE thread in the DIY thread has something about that were the guy hooked up a system and drove down the road while monitoring the gauge.

 

Well I checked it today and I am not losing vacuum under load... It drives me nuts.. I would see if the IWE's were trying to engage right, in the CV axle's turning just a bit when they touched together or just outright turning because they made a connection?

No sounds what so ever except some clicking from the front every so often, just a 'rough'/slight vibration sensation through the floorboards I swear is coming from the front. dumb question since every bearing I have ever seen go bad you 'hear' (John Deere bearings sing like no bodies business when they drop bad ); is it possible for them to crap out and not make a noise?

The only other thing I can think is somewhere in the transmission something is worn out... But i just changed the fluid and there was no chunks of metal, and not much in the way of shavings except on the magnet. I did a visual inspection and saw nothing I considered out of the ordinary?

 

Matt not to throw you for a loop but I had an issue like this that drove me insane. My problem with those sounds turned out to be a loose cam bolt on the bottom of the lower control arm bolts on the rize frame. Some how that massive bolt worked it way loose, but it was still really tight with a wrench on it, just enough to clank and make noises when taking off and slowing down (unloading and loading of the bolt.) I mark my cam bolts now with a paint pen for this exact reason.

I had a IWE problem with low vac and the noise was soooooo loud when it started to grind it was insane.

 

Clicking sounds do not sound like the IWE's. The IWE sounds are like what sbchris said because they are annoying. Its like a screaching type sound idk. But also have you checked out your Driveline up front?

 

Chris, I'll have to see about the control arm bolts, I have always had a suspicion that even though they were tight they wiggled around like you said.


Mhockey-- I'm certain now that the IWE's checked out, and the front driveline is all brand new as of earlier this year (for the 3rd time in the trucks lifted life)... the truck is at a mechanics shop today for an alignment and to see if he might be able to diagnose it; I told him to check all the front end components to see if I overlooked a worn part. In talking with him this morning though we both seemed to agree its sounds like a transmission part wearing out or failed already; my only qualm with this theory is the truck shifts fine and runs great. just has this annoying roughness emanating from somewhere..

 

Maybe the transfer case sense its closer to the front of the truck?

 

FX4life, Did you ever get this issue resolved? I am having a very similar problem. I just had my lower ball joints replaced and now I am getting a vibration from the front suspension. I can feel it in the steering wheel and floorboard and also like you it is most noticible at low speed 5-10 mph while speeding up or slowing down and around 50 mph. I don't get a metallic noise though it feels and sounds like a put a set of mud tires on the front.

 

I kinda gave up on this issue, I checked the IWE's and a mechanic said the wheel bearings checked out, I checked all the front bolts, the front driveline checked out... I still have the issue's though. I'm thinking its in the rear of the truck now, see my 'truck shuttering thread'. The only thing I have not tried on this issue is putting the truck up on jack stands and 'driving' in 4wd and looking at everything to see if something is happening I obviously would not see while driving or watching someone else drive it. My new tires did help a bit...

I have had a long standing theory that my transmission is going to leave me soon It's just way too expensive to tear it down and find out it was not the issue...or was the issue and costs an arm and a leg..

definitely if someone else finds a solution to our similar issues let me know. I have a rear driveline issue right now that is eating up rear pinion seals

 

Darn it I was hoping you had the answer! My initial thought was it was a wheel bearing. My tires are new, less than 2000 miles on them, I had the exact same tires before these so the fact that they sound and feel much rougher after a ball joint replacement has me puzzled. I haven't had a chance yet to put it on stands or jacks and check it out. I just had it done last Wednesday. Something could be loose I guess? Maybe turning the tires while off the ground will reveal a bad bearing for me. I usually would have time to look at this good but it is right in the middle of hunting season here and all me free time is spent in the woods!

It's always something!!!

 

You ain't kidding about that.. Lately it seems like my truck is just pushing my buttons to see if I will or won't go get a new one I stopped modding and showing the truck; I just wanted to drive it and enjoy it for a while before getting into a new one.. So far I have spent all damn year fixing things... I never had this much trouble with the truck in the last 4 years, now all the sudden I can't even find all the things wrong somewhere >(

 

I seem to have the same problem on my 2005 F150 SCrew FX4 4x4 - for about 2 months now I have heard a sound that I would normally think is a bad bearing but I jacked the truck up and didn't feel any play in any of the wheels. I think I have a bad lower ball joint so I am going to replace that and I do need an alignment but I can't imagine that this is causing my problem. It sounds like a bad bearing on the front drivers side wheel and i can feel a vibration in the floor and the steering wheel. The vibration and noise seems to fluctuate with the speed of the truck - it is definitely a rotational sound. Is this the same type of symptoms you guys have? Any new developments from anyone?
Thanks!

 

well you can see my new thread, currently above this one in the 04-08 forum. It seems my issues stems from a faulty gear installation that trashed the entire rear axle. My growing shutter/vibrations where from the axle finally self destructing after 60k+ on a faulty gear job I would highly doubt this would be the cause of most of you guys that are still running factory rearends/gears problems.. you never know though, I guess.

 

Dam Matt!!! I had a feeling you would report back with something like this... EEK, might have to check mine out now! Wouldn't be the first time I've blown up the ring and gear before also.

 

I would check them Chris, he guaranteed me this was 95% of my issues... the grrrt-grrrt when letting off the gas, the vibrations, the shutters, the crappy 4wd engagement.... he also told me a double cardan joint was too heavy for our tailshafts, is it really? I don't know... for just the rear i'm 1600 in the hole for parts and they are taking the front apart this morning... In short this had BETTER be the real issue, I might lose my mind if it isn't..