I used my 4wd the other day. I was in 4-low going through some really sticky clay mud. She started to bog down and I got on the gas to clean off the tires and keep her moving. When the truck shifted gears (up-shift from 1st to 2nd) there was a VERY LOUD clunk that sounded like it came from the front end. It sounded like the front ends ring an pinion jumped a tooth or something. Not sure if it was from the hubs or the differential. This happened a total of 3 times while going through the mud, not all at once but randomly.

The truck seems to be normal while in 2wd, no clunks, no unusual noises. When I crawled under the truck, there are NO oil leaks and the fluids are full and clean (I didn't drop any pans or anything, just stuck my finger in the oil to check it), the CV boots are good with no tears, everything looks good...this makes me think that it's internal to the differential. I also checked the vacuum lines of the hubs and started the engine to make sure they are engaging and disengaging...all seems normal. One thing I did notice was with the engine off (no vacuum, hubs default to locked without vacuum) I grabbed and twisted the front CV axle's and they will turn about 1/3 turn in either direction with a small clunk when it stops that sounds like it's coming from the hub. I think this is normal but I'm not sure, it does seem like a lot of "slop".

Any help with this would be great! I'm not sure where to start. The truck is under it's power train warranty, but I have installed the Bilstein 5100's...do you think Ford would decline the warranty due to the sharper angles on the CV joints from the 2" lift?? I drive and use my truck everyday and cant afford for it to be sitting at the dealer for a week or two being fixed...(if they have to replace the front axle)

Thanks for you help on this!!! All the truck info and mods are in my sig.

 

bump

 

No help....????

I'm tring to decide if I even want to deal with the dealer or take this as my opertunity to regear and change to some electric lockers. If you guys think that there might be a larger problem them I'm going to take it to the dealer, if not then looking at the gear swap... What do you think?

 

Ya, well thanks anyways guys for helping me with my problem. It must just be an amazing phenomenon that only my particular truck has ever had this problem in the entire history of automobiles. Maybe I should return it to Ford for extensive research. That way when your truck runs in to the same problem then maybe Ford will know what to do.

 

hey man mine does that when i turn in 4wd i think it's the hubs...thats my opinion though..im not a pro i had my gears changed and my transfercased changed and it still does it..hope that helps

 

So it's not something major to worry about? It just doesn't sound normal, that's all.
Sorry about my sarcasm in my last post, I was just getting rather frustrated that no one was helping me out with this...

thanks for the info

 

how many miles are on it??? sounds like front universals, i would take it to ford and get it checked out if its under warranty, why not. i don't think that they would void a warranty for a leveling kit and shocks

... and if you jumped a tooth on the ring and pinion you deffinatly have bigger problems

 

Most likely the cv's got bound up and then popped when they unloaded.

There's no way for it to "jump a tooth" without destroying the gears.

 

I agree, if a tooth jumped then it needs a new front axel. It has 34k on it. I know it's under warenty, I am worried that Ford will void my warenty due to all my mods. I don't want to take it in for a something that might be a common sound and then the next thing I know the dealer voided my warnety due to some other mods.

If it's the CV's then it sounds like they are worrren out... I havent used 4wd all that much, seens they shout last longer then that... Is it common for CV to do this or is this a sign of wear?

 

It usually happens in higher traction terrain while turning left or right. Sticky clay mud may fit that bill. It's a pretty common occurrence when in 4lo. At least it is with me

 

most likely just a loading and unloading, like everyone else said.

there really isn't a reason to be in 4lo while just mudding. that could actually make things worse.

 

I just got it back from Ford, they inspected everything and were unable to get the truck to do it again. They did say that there is some wear on the steering stops on the lower control arms, and that could have caused the noise if I was turning sharp while going over rough terrain. They said that if they can't get the truck to make the sound again while they have it, they cant narrow down where it's coming from. They told me to bring it back if it does it again.

I'm thinking that it was just binding like you all said. I'm not that worried about it anymore after seeing that Ford doesn't seem all that concerned about it (I went out to the service bays and talked with the actual mechanics out there, rather than the service writer that spends all day in the A/C), and you guys say it's just something that happens sometimes...

 

I was towing a 100kw generator at the time. I needed the lower gearing. I wasn't out playing in the mud, I was on a job site that got flooded out by a water truck. All was fine going down the mud until I got to a low section in the road that all the water had drained to. That's when it started to get real muddy. I stopped put it in 4-LO and went on. If I left it in 4-HI I would have gotten stuck.

I'm just trying to explain the situation I was in...

 

Yeah I've actually had my truck make that "popping" sound several times while in 4wd... usually while turning the wheels... and it happens a lot in 4lo when I first shift into 4lo and then shift back to drive.... It makes a loud pop or clak and then goes on... I mean, my brother's tahoe does it too every now and then, but he has stock angles... I have a 3" level kit - soon to be replaced with coilovers though so Im thinking it could be the CVs binding :/

 

Mine does it too, never figured out what it was. Only does it in 4wd while turning the wheel............