Hey guys, I have an '08 F250 CC Lariat 4x4 with a V10 auto and a 4.10LS gearset. There are 87,xxx miles on the truck and up until yesterday, there were no strange noises whatsoever. I put in a 3" front coil spacer and 5" rear block last night, and changed to some wider wheels and tires. Immediately after install, it picked up a small growl in the rear somewhere with really no rhyme or rhythm as to when or why it happened. I checked everything; U-bolts are tight, tires are balanced, U-joints appear to be fine with no odd clean spots from rubbing, etc. I drove it 40 miles, just ran to town to get some stuff and when I was almost home it began this horrendous howling from somewhere back there strictly on deceleration and under 45 mph, but yet still maintained the original growl as well! The only thing I can imagine is the rear diff is hagged out. Call me crazy but it just seems awful fishy that simply lifting it 3 inches should destroy pinion angle enough to roach a diff.... Does anybody have any idea what this may be? Perhaps I'm overlooking something obvious but I can't put my finger on it. Thanks in advance!

 

got any pics ???

hard to help without seeing your trucks install.

maybe something is installed wrong ???

 

I can certainly take some pics, but not sure if I'll be able to figure out how to load them. It was a simple block swap, pulled out the 2's and put in 5's with new U-bolts. I'm pretty certain it's done correctly but I'll see what I can do about pics

 

Is your truck a long bed. If so did you use a tapered 5" block. Did you adjust/shim the carrier bearing. Its either the axel to bell housing not aligned or something with the rims tires rubbing. Something that spins that is causing the noise. In the rear you used a 5" block so you went up 3". actually I think you went up more. I think the correct rear stock block on a F250 of that year is approx 1 and 3/4 inch. (someone will chime in if I am wrong).

 

It's a short bed, and I don't believe the block is tapered, nor did I adjust the carrier bearing. The block I took out measures exactly 2" all the way across. I was told this was a bolt in install with no other adjustments. I just jacked up the read to eliminate wheels/tires from the equation, and same noise. It's something in the rotating assembly but I can't see what. The U-joints have all the same rust on them everywhere, not like they're hitting due to pinion angle anywhere. I took some pictures and a video, I'm trying to upload them now but having problems, it says I may not post attachments to this site

 

Short bed no need for tapered. but I would still look into the carrier bearing. When they say bolt in, I take it as you take out the old and put in the new without having to modify the part you are dealing with. You still may have to adjust the carrier bearing.
Most people on here do not have a problem when replacing the 2 " block for the 4" block. You went with the 5" thats different. So I would look at that. If you have no wear marks due to the new rims and tires. the only other option to look at would be that carrier bearing.. Considering you only did change the blocks and u-bolts. its all you have left to look at. Oh and get a complete alignment from a shop that does 4X4's..

I am trying to find a post on here from awhile ago. short bed with lift vibration and growl. It ended up being both. He had tappered and had to change them.. He also had to add to the carrier bearing. When i find it i will post it..

Well when reading this post over again. I would recheck what kind of blocks you have. I am sure you did but it could never hurt.

Ok found it:
https://www.ford-trucks.com/forums/1...ituations.html

 

dont be surprized like any wearable part if it turns out to be U-joint/wear/noise...

think about it, for the life of those Ujoints they have been operating within a certain angle/degree.. now you just changed that degree by quite a bit..

the potential for noise is high..first thing i would do is lower the carrier bearing, that will help. bit in the end it might just be ur U-joints are dry/worn enuf to require replacement to eliminate teh noise..

are your U-joints greasable ? i bet they arent if factory original units.

ps my truck has a 4" lift and its a SB/CC aswell, and my truck uses a carrier bearing drop.

 

Well, I feel like a moron! I was doing this diagnosis alone so it was tough to decipher exactly where it was coming from, but I had a buddy help me out last night and I crawled underneath while he got it up to speed with the rear on jackstands; turns out the noise I was hearing was coming from the transfer case! Now we're opening up a whole new bag of marbles.... What the hell could possibly make that happen?! The angle on the output shaft never even changed- fluke accident/coincidence?

 

Bump- Anyone got an idea for a crunchy/grinding t-case above 30mph, speed specific not rpm

 

ok, just to make sure...

your not driving down teh road with teh hubs locked and the 4WD on are you ???

 

Hubs are in auto and it's in 2wd. I tried flipping into 4x4 today, thinking maybe it was just hung up in between, but that made it even worse

 

fluid level ???

its def. starting to sound like you somehow have a problem in the transfer case..

 

Fluid level is good, and it looked extremely clean as well.... At any rate I was pulling my hair out so I just took it in last night, we'll see in a couple days I'll let you guys know. I was also meaning to ask originally; when I put the lift in, it seemed as though the track bar was too short, forcing me to pull the axle off center toward the driver's side an inch. Is there a relocation bracket of some sort for the bar or is that just how it's got to be?

 

There is a drop track bar bracket, but there is also an adjustable track bar. I have the ICON bar.

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