Binding in rear end when warmed up

I have a 2006 4wd 4.7 L truck. After driving for at least 45 min I begin to feel something in the rear end binding and hear a popping/binding noise when accelerating from a stop. I had my mechanic look the truck over and he found nothing that looked worn out. He couldn't duplicate the problem since the truck hadn't been driven long enough when he looked at it. He said there was no unusual rear brake wear going on so not likely a brake issue. The binding is pretty severe. I will put the truck in gear when it's hot and release the brake and it won't even move on a level surface. I have to press on the gas and then I hear the binding/popping noise. Could it be the rear carrier bearing? I took a video of the rear end spinning after I jacked it up. Doesn't seem to bind unless it's under a load.

 

Carrier bearing or you need to grease your driveshaft. It needs it from time to time.

 

I do religiously grease my driveshaft. Question... whats the little flat head screw for on the underside of the carrier bearing? There's a hole in the housing and u can see a small screw up inside. Possibly a spot to add oil? There is some play in the drivshaft at the carrier bearing but the rubber looks fine from the outside. My mechanic didn't seem to think there was excessive play at that point.

 

How much play is too much for the carrier bearing. I do get vibration while driving at times. Enough to shake the passenger side front seat. How do I upload a video if it's in MP4 format?

 

The drive shaft should be pretty steady in the carrier bearing. The bearing rubber shouldn't look collapsed, it should look symmetrical. Your symptoms don't sound like carrier bearing to me. They sound like rear axle. Like brakes or gears / LSD issues.

 

Warm it up, put rear on jack stands and try and turn the wheels by hand.

Sounds like internal differential.

 

Thanks for all your help, really appreciated! One thing seemed odd to me. When I jacked up the rear end the other day, I only jacked up one side at a time. Then I started the truck and put it in drive. One rear wheel would spin in drive even though the other wheel was still on the ground. My mechanic told me last yr that he had to add a special additive when changing the rear diff fluid because my truck had the limited slip differential. I shouldn't have been able to spin only one wheel when I had it jacked up on just the one side then, correct? Just a thought. I'll be checking the rear diff fluid level 2day and looking to see if it's contaminated.

 

Sounds like a worn LSD or an open diff.

Factory LSD isn't that strong and may slip in drive with one wheel on pavement.

Also that was a fairly unsafe test. If it grabbed it would have driven right off the jack stands/jack and into anything in front of the truck. Not recommended.


The additive is to quiet chatter when turning in a parking lot. Not the issue you're facing.

 

stupid me. Won't do that again. Would have driven off a ledge into the woods!

 

So worn LSD = rebuilt rear end ?= $$$?

 

Throw it up on jackstands again with both in the air. See what it does. You can grab a tire and stop it to see what the other side does. Do you have a sticker on your diff above the fill hole?

 

So spin one tire at a time and see what happens when I stop the tire? Sorry, not sure what u mean.

 

I'll look 4 the sticker. I do have the LS rear end.

 

Put it up on 4 jack stands then put it in D, or have someone else do it while you watch and listen. You can grab a tire to stop it spinning. With an open diff the other side will start going backwards. LSD I'm not sure.

 

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Thanks @bmf4069 for getting us back on track with the LSD. Now, about that rear end action...

 

Safer to leave the engine off and put it in neutral if you're going to be grabbing tires.

Easiest way to check for LSD action is to do a brake stand on a loose surface (dirt, snow, etc.), see if both tires spin or only 1.

 

I'm still totally stumped on this issue. I jacked up the rear end after driving for over half hour and the binding/popping was occurring in the rear end. With both rear tires off the ground, running the truck in both forward and reverse, no binding noise at all. Put it in neutral and spun tires in both directions, the other side always would spin in the same direction as the tire I was spinning. No binding in neutral but seemed like alot of play in the diff when switching directions whole spinning tires.wish I could figure out how to post video on here.

 

The opposite tire does rotate backwards when the truck is in park.

 

Sounds like normal LSD operation to me. (Same direction in neutral and opposite in park where case is held still.)

How quick did you get it up on jacks? Could it have cooled down enough to stop binding?

 

Reaaalllly dumb question....... Is the 4WD engaged?

 

No, definitely not in 4wd or it would have driven off the driveway. I did jack it up immediately when I returned home. I checked the diff fluid level yesterday and it was fine. No burnt smell from the lube and it looked fine to me. I'm just going to have to take it 4 a long drive after work and then pull it into my mechanic and let him drive it. I'll be sure and post what he finds.

 

Not really related to this problem I'm having but I noticed the bottom of the diff pumpkin is rusted bad. I saw one youtube video where a guys was rusted completely through to the point that it started leaking. Any suggestions on what you guys would do to slow down the rot that's happening? Just paint it or use a rust inhibitor?

 

I did wire brush all the loose rust off already.

 

Once the steel starts flaking off like that, I'm throwing in the towel, it's going to continue whether you like it or not. Even if you coat it, it'll just keep chipping under the coating. You can try using a rust converter. Eastwood makes great products for this. You could try wire-brushing it to get to get steel (if it exists), then coat with an Eastwood product or POR-15 (wear gloves).

If this is on the removable side, the cover, I'd just go ahead and replace it. If not, one of the above suggestions may help. Nothing beats getting past the chips and into clean steel, then coating. But steel is only so thick and needs its rigidity.

 

Not on the removable side so I'm screwed there. I just picked up some of that POR-15. Hope it helps. Guess I need to start a savings account for a rear diff replacement. Not even sure it's worth it on a 2006.

 

Oh, it's absolutely worth it. You could use a service like car-part.com to hunt for a replacement, you never know, maybe you could find one with LSD or something. If the original cover is on it, the LSD units typically indicate it on that cover by sticker, if still intact.

But that said, if you go with POR-15, read the instructions carefully. Wear gloves, it'll cure rapidly on contact with skin, like superglue. Knock as much old rust off as you can using whatever mechanical method you can until you no longer see layers chipping and flaking away. I'd probably attack with a heavy-duty thick-tine wire wheel followed by a flapper, or if you just want fast results and you're skilled with one, maybe a die grinder.

POR and Rust Bullet are both similar and great products. If I really need to seal something up, I'm usually grabbing for the POR-15, but I know a lot of products have come out since then which may be better at re-encapsulating rust-infested steel.

 

There are cheap ways to do it that seem to work for others once theirs leak like JB weld or 47 layers of por15. On my FIL's truck we just went ahead and got a whole new axle housing and swapped all components over. Took the axles to a shop to have the bearings pressed off and on. I don't fully recall the cost of all this but I believe it was between $1500-$2000. Hopfully you can coat it good and get some more life out of it. May want to take a good look at the rest of your frame if your axle looks like this.

 

Great, thanks for the good info.

 

Just watched the video. Is there a bearing noise? When you had the camera near the driveshaft to rear end connection, it sounded like maybe there was a pinion bearing noise maybe? Also, if your mechanic said something about an additive for the rear diff, maybe the wrong additive was used, causing the LSD to operate abnormally? Binding severe enough to make a truck hold against the idle while in gear does not sound like a bad bearing. Something mechanical is likely going on. I would suspect the rear differential if the brakes have been ruled out.

 

Update on the binding issue I'm having. Had my mechanic take a ride with me when the truck was making the noise in the rear end. He thinks it sounds like the LSD clutches are binding. Causing the chatter. It primarily does it when turning. He suggested adding another 4 ounces of additive to the diff. What do u think? He said it's worth a try. Have to research whats recommended for this truck. Otherwise he said they'll have to pull it apart and try to see what's going on.