Humming noise with hubs locked

[Skandocious]

Okay don't go jumping to conclusions based on the title, theres more to the story.

I went to the snow this weekend and had to use my 4wd. Got out, locked the hubs, got in the truck and hit the button. Light came on and all was good. Started goin agian. Well as soon as I had to pull my foot off of the accelerator (to let the truck coast down a hill), I heard grinding/humming noise coming from somewhere in the front end. It stays for a second or two then it goes away. But as soon as I step on the accelerator it comes back for 1-2 seconds and goes away again. Then repeats if I take my foot back off --- etc etc.

So it seems to only make this noise during the transition from power-to-coasting or coasting-to-power. And yes my 4wd was working fine with this noise, I tested it by gassing it hard from a stop and all 4 tires spun in the snow, also checked to make sure both my axle shafts and the front drive were spinning with the trucks movement, affirmative.

So what the heck?! I'm thinking either a bad u-joint somewhere or possible (ahhhh!!!) the guy that did my gears recently setup the front pinion wrong. The u-joints on the front driveshaft and axle shafts are (I believe) original to the truck. I plan on replacing the driveshafts joints this weekend but man I don't wanna replace the axle shaft joints

Anybody got any ideas?

 

[Skandocious]

Also, earlier I left my hubs unlocked and drove down a straight road at about 30 mph, then turned on my 4x4 (push button 4wd). With hubs unlocked and 4x4 enabled, no apparent sound was coming from the front end... That is, all front drivetrain components spinning but wheels are getting no power with hubs unlocked. Ehhh... What the heck?

 

[blacksnapon]

Yep, checking u-joints are in your future. Keep in mind. that locking it in without your hubs, isnt a definate. There isnt any load on them that way (you said it is quiet in the transition from power, to coast). It still may be a bearing issue.

 

[Skandocious]

Yep, checking u-joints are in your future. Keep in mind. that locking it in without your hubs, isnt a definate. There isnt any load on them that way (you said it is quiet in the transition from power, to coast). It still may be a bearing issue.

I'm not relying on that no-hub 4x4-on method to make an conclusions, it was just another observation.

And I'm not sure if you read my post correctly but it was most definitely NOT quiet in the transition from power to coast, not with the hubs locked that is.

And the wheels bearings are all new on both sides. Replaced them (and greased the new ones liberally) when I did my front brakes.

 

[blacksnapon]

Sorry, poor verbage. When you find something that changes the noise (either good, or bad) you're at the same place that the problem is. Just trying to say, the Load/no load, makes a change in the noise. The hubs not locked in, is a no load situation. The bearings I was referring to, are the "carrier bearings" or "side bearings" on the differential.

 

[Skandocious]

The bearings I was referring to, are the "carrier bearings" or "side bearings" on the differential.

Those are also [supposedly] new. The guy that installed my gears a couple months ago also did complete rebuild kits for both diffs. I believe that he because the seals that are visible look shiny and new.

 

[eco]

Did you ever get this one figured out?

 

[Skandocious]

Damnit. How the hell did you find this site?

Beware eco, I'm good friends with the admins here and if you start being an ass I'll have you kicked out dude. And no I'm not joking. This forum is STRICTLY for friendly people and anyone raising hell (not in a good way) will not be tolerated.

 

[eco]

Slow down tiger...you must have me confused with someone else.

 

[O'Rattlecan]

sorry eco. Don't mind chris. There's always a blacksheep.

Ryan

 

[mrfixit]

Is our resident Hippie having flashbacks???

ECO... maybe there IS another with that name elsewhere, but this site is
"Wild West" kinda friendly, lol... You are who you say you are til you prove otherwise

As for the HUMMING issue... Maybe your truck is changing....







into a HUMMER!!!

 

[6L PWR]

into a HUMMER!!!

OH GOD NO!! Is PB having an effect that's transferring into our trucks?!?! We may have to BANISH him!!

 

[Skandocious]

If you truly aren't the person that I know from the other forum then I apologize. There is a user that harasses members on another truck from under the username 'eco' and I'm not about to let him come and harass our members over here.

If you ARE the same eco then please be a man and fess up. If you can be on good behavior then we'd love to have you here, but as I said, we're not going to have trouble makers on this forum. I've already had an extensive phone conversation with one of our admins here and they're all keeping an eye on you.

Again, if I've got the wrong guy then I apologize. But you coming on our forum under the same username, and immediately posting in MY thread without any kind of announcement about your joining our team, seems a bit suspicious.

 

[d-kuzmen]

Okay don't go jumping to conclusions based on the title, theres more to the story.

I went to the snow this weekend and had to use my 4wd. Got out, locked the hubs, got in the truck and hit the button. Light came on and all was good. Started goin agian. Well as soon as I had to pull my foot off of the accelerator (to let the truck coast down a hill), I heard grinding/humming noise coming from somewhere in the front end. It stays for a second or two then it goes away. But as soon as I step on the accelerator it comes back for 1-2 seconds and goes away again. Then repeats if I take my foot back off --- etc etc.

So it seems to only make this noise during the transition from power-to-coasting or coasting-to-power. And yes my 4wd was working fine with this noise, I tested it by gassing it hard from a stop and all 4 tires spun in the snow, also checked to make sure both my axle shafts and the front drive were spinning with the trucks movement, affirmative.

So what the heck?! I'm thinking either a bad u-joint somewhere or possible (ahhhh!!!) the guy that did my gears recently setup the front pinion wrong. The u-joints on the front driveshaft and axle shafts are (I believe) original to the truck. I plan on replacing the driveshafts joints this weekend but man I don't wanna replace the axle shaft joints

Anybody got any ideas?

You may want to check your front diff bearings, as you load and unload the diff with the hubs locked the sound will change slightly. The pinion preload could be wrong or pinion depth not set properly. Make sure your pinion flandge doesn't have any up/down or in/out movement (check with the truck in 2wd hubs unlocked) if so theres a problem there. Also check to see how easily it spins by hand, you should be able to turn it without any effort.

 

[Skandocious]

All the differential seals, bearings, and shims are SUPPOSEDLY new. The guy did rebuild kits on both diffs when he swapped my gears, and the visible seals look very new so I'm assuming he actually did do it.

I'll check for play on the pinion when I can. I have spun the driveshaft by hand in the past (to make sure my hubs were unlocked) and it very easy to do it by hand.

Your theory about the pinion backlash not being set properly is what I'm thinking the problem is, but that theory isn't founded and any sort of hard evidence. I was going to check it all out this weekend but I ended up having to come down to the bay area for my moms birthday, so no truck worth 'til next weekend

 

[eco]

If you truly aren't the person that I know from the other forum then I apologize. There is a user that harasses members on another truck from under the username 'eco' and I'm not about to let him come and harass our members over here.

If you ARE the same eco then please be a man and fess up. If you can be on good behavior then we'd love to have you here, but as I said, we're not going to have trouble makers on this forum. I've already had an extensive phone conversation with one of our admins here and they're all keeping an eye on you.

Again, if I've got the wrong guy then I apologize. But you coming on our forum under the same username, and immediately posting in MY thread without any kind of announcement about your joining our team, seems a bit suspicious.

It would be slightly helpfull if you would specify which site and which eco (assuming there is more than one out there) you are thinking of...don't you think? If you are thinking of FORD TRUCK ENTHUSIESTS then yes, same eco. But, with all the hell raising and harrassment verbage I was led to think that you must have me confused with someone else since I don't do any of that.

 

[Skandocious]

Figures.

Watch yourself eco. I'd love for us to get along and be friends, you've a very knowledgeable guy, but you allow your sarcasm and general bad attitude to stand in the way of being helpful to other members. On this site we all watch each other's backs, admins included. Step out of line and I'll have you booted. I don't have the power to make that happen on 'the other site' but god knows I've got it here.

That being said, I'll reiterate myself. I'd love for you to become more friendly and become part of our FTF family that's been built here. I think a good start would be to tell everyone your REAL name, no more mysteriousness.

 

[mrfixit]

Many people have had issues "Over There" and come away with some hard feelings. Consequently we have decided to NOT make that site an issue here, and everyone gets a fair shake at being part of the family.
Just to reiterate for new members... No site bashing, no flaming and no harassment here. We tease each other, yes. Most of us are adult enough to know the difference and also are sensitive to known experiences elsewhere on the web, so we check the past at the door and we watch out for each other here.
If that's all good to you, Eco, Welcome.