I have a 2005 F 150 Lariat. when I grab a wheel and shake the truck from side to side I hear a clunking noise comming from the rear axle also on occasion the rear of the truck seems to hop up and down it is not tires just had new tires installed and it still does it; 40,000 miles on the truck. Any ideas ? thanks. Bob.

 

Limited slip? May be time for some more friction modifier or change the diff fluid and add friction modifier.

 

Sound like this?

http://www.youtube.com/watch?v=N4Bm6...layer_embedded

 

experties thats what it sounds like but whats the fix ? I also believe it is limited slip What would the code be on the door jam to find out rear end size and limited slip ? Thanks. Bob.

 

Well Bob, I have taken my truck into my local dealership 2 times, argued and dealt with the GM and they claim that is normal. It seems worse because I have over sized tires therefore I have no fix for you. I was told they confirmed it with other trucks BUT I have yet to be able to perform this issue on any other trucks.

Sorry I wish I could help you because it worries me.

 

had that on my 04 with about 5k miles on it, dealer put whole new rear end guts in axle, you can hear it when you take turns, right ? it's a chucking sounds like it's sliding then stop's

 

Funny you say you argued with the GM, my dad is a GM at a Ford dealer and to put is nicely, he doesn't know much about mechanical work. He is there to make sales and to make the dealership profitable. Also when it comes to the service work he will just back up and agree with whatever the service manager says.

 

My truck kinda does the same thing though, but I haven't had it checked out or looked at. My friend has a dodge that sorta did the same thing and his fix was new Ujoints on the yolks of the power axle.

 

Loose Spare Tire?

 

sounds like maybe your bearings are shot, ither that or you may just have alittle to much play in your rear end take the diff cover off and there should be 4 bolts you will be looking at in the rear end go online or ask the dearlship what the torqe rating is on those bolts and try re torqing them they may just be loose, just an idea for you, also while the cover is out inspect the rear jack the rear end off the ground and spin the tires looks for chunks missing in the gears or on the bottom of the diff after you drain it look for chunks of metal if there are pretty big chunks of metal on the bottom, you might want to have it looked at by a professional, and come to think about it i think my truck does it but only a tiny tiny tiny bit, probably because ive replaced my rear end in my truck once and 4 times in my old truck, so i have a little knowledge on this

 

Actually that's not terribly uncommon. It's probably a little bit of wear where the "C" clip goes on the inner end of the axle before the axle is pulled back out to seat the clip and install the cross pin. Jack the truck up and see how much play you have on either side just pulling in and out on the wheel. Bet there's not much. When you go around a corner or yank back and forth like that, you have a lot of weight moving quickly back and forth on the sidewall movement on the tires. If you can't detect much when you try and do that with it on stands, I don't think you have any problem. For it to wear either the pin, groove in the end of the axle, or the "C" clip enough to cause any problem, you would have to have 700k mi on the truck or some parts that didn't get heat treated or were HORRIBLY abused. Try it on stands so the weight of the truck isn't doing you're work for you and I'll bet you don't have any movement (maybe a few 1000th's, 10-30) which it should have. I've seen many cars and trucks that you can do that to with absolutely nothing wrong with them.

 

Have an S331 guy with the Same problem on another board. Ford is swapping his entire rear? However, everything is on backorder until God knows when (per the dealership)