I have a 2005 f-150, XLT, 5.4, 4x4. Every time I make a left or a right hand turn, from a dead stop, I feel a few jolts in the rear of the truck. Sometimes it does it, and other times it won't. Before I take it to my mechanic, I'd like to see what I may be able to do before I here the typical mechanic bull, and fork out a lot of money. The e-brake does work, and isn't hanging up. I recently changed pads, and the rotors were fine. Could the calipers be hanging up, or the sliders in the breaks? How would I know if the bushings are going bad? Or could it possibly be the rear-end getting ready to go? I never tow with my truck, I never have weight in the bed, I don't go off roading. Hopefully I gave enough info for people to give me some suggestions.....thank you for your time.

 

sounds like it may be time to change the rear end fluid and put the friction additive in it. being a 4x4 it most likely has a limited slip rear end which has clutch like plates.and requires an additive not sure of the miles but may be time to change it. or if the rear end oil was changed and the additive was not put in it. it will give you a pulsing vibration going around corners.

 

I agree with t lindemann sounds like a fluid change is in order. I had the same issues in my truck, changed the fluid and all is fine.

 

I drive a 04 that had a tsb out on the same issue . The dealership took care of it free off charge .

 

Is it a shudder or a clunk?

 

You need to have the clutched changed. This has been a known issue with the 04/05 rear ends. Worse on the explorers, but my 04 has started to do it again as well and it was rebuilt 3 times under warranty. Unfortunately, for me now, I'm passed the warrantly, so I'm debating on what to do

 

Someone sugggested (and said it worked for them) long ago that you need to take the truck to a large parking lot and do a bunch of tight figure 8s to force the clutches to slip and loosen up and let the lubricant work.

 

It's more along the line of a shudder. I changed the rear-end fluid today, and put the lubricant in also. To no avail, the feeling still continues. I actually did the figure eight thing today also, per mechanics request. No change in the rear-end. I just may trade this heap in on a Nissan.

 

Trade it on a nissan.......Rethink that move. I have just bought an 01 and amhaving the same issue with the rear end. The modifier does take a while to work its way into the clutch packs though. I actually got into it with the svc mgr at the dealer....he was telling me I had an open diff, and I asked him why it says LS on the tag, and also H9 on the door jamb?He made parts look it up and they evenhad a hard time finding it believe it or not!! . I am waiting a bit to see if the change made any difference. Does yours only do it once the rear end gets warmed up? Mine never does it when the truck is cold.
Rich

 

It does it when is it cold. However, when it has warmed up.....it does it horribly. Passengers in the car start freaking out, thats how bad it does it.

 

Thats how bad mine was...you could feeel the shudder athroughout the whole truck, but like I said, mine NEVER does it when the rear is cold. I had them do a oil change and add the modifier. Its only been a week now and its still there, but not as bad. I would replace the clutch packs myself, but I have no idea what to even look for when having it apart.

 

Seems to be a clutch pack issue or a slip yoke issue...

For ref: There should be quite a few threads related to the thump/clunk upon take-offs and low speed maneuvers.

Here's a few TSBs that may help:
https://www.ford-trucks.com/tsb/full...p?tsb=05-26-11
https://www.ford-trucks.com/tsb/full...hp?tsb=05-13-1

 

Go ahead, trade it in. Nobody here is going to stop you, nor will it hurt anybody's feelings. It also will not get your problem fixed any faster to talk about trading it in.

Now, as far as your original problem goes, the clutch packs need to be replaced. It is a fairly straight forward job.

 

Can you please post which fluid and additive you used? Thanks

 

I'm no rearend guru(no pun intended) but would it be any better to switch to an open instead of a limited slip if/when the rearend goes out. I see that many of the newer 4x4s have an open axel type. Just wondering in case I run into this.....