Clunking noise after accel while in 4x4 - Ford F150 Forum - Community of Ford Truck Fans

2004 - 2008 Ford F150 General discussion on the 2004 - 2008 Ford F150 truck.

Clunking noise after accel while in 4x4

Thread Tools Search this Thread
Old 11-10-2010, 03:28 AM   #1
Junior Member
Thread Starter
Join Date: Oct 2010
Location: DFW TX
Posts: 21
Thanks: 0
Thanked 0 Times in 0 Posts
Default Clunking noise after accel while in 4x4

I dont know if this is more of a transfer case issue or a differential issue, I was hoping you guys/girls might help me shed some light in the subject. Here is the scoop.....

Let me start off by saying that none this happens while in 2x4. FWIW, the truck engages into 4x4 mode rather easy. No clunking/thud is made when I shift from 2x4 to 4x4 (parked or while moving). I notice the thud/clunking sound predominantly after acceleration, either accelerating from a dead stop or accelerating while cruising, it doesnt matter. I can feel it in the front end. The clunking/thud is deff coming from the front end. It may be doing it in the rear, if it is I cant hear it. It is quite loud at times. I wouldnt call it a violent thud, maybe an agressive thud.

Additionally, I noticed another noise/issue while backing up in 4x4 a day or so ago.....while backing up it there was a sound coming from the front/under that sounded grinding/whinny noise. The noise kinda resembles the sound of "grinding the gears on a manual transmission/clutch". Although this sound was more whinny than grindy. Nonetheless, the sound my truck made when this happened was still similar to the gear grinding sound that happens on a stick shift automobile. Additionally, the intensity of the sound was greater with more acceleration. Again, this noise only happened while in 4x4 and while moving in reverse.

I bought the truck about a month ago. It has about ~70k on the odo right now. I am going to differentials, transfer case, and a tranny service soon. I dont know if the noise(s) are due to a lack of service. However I was wondering if you think a fresh differential/transfer case service would take care of things. What do you think, is this a differential issue or a transfer case issue?
havhon is offline   Reply With Quote
Old 11-10-2010, 06:45 AM   #2
iTrader: (1)
techrep's Avatar
Join Date: Jan 2009
Location: Va. Beach, VA.
Posts: 31,063
Thanked 1,449 Times in 1,299 Posts

Check all the u-joints on your front drive shaft.
techrep is online now   Reply With Quote
Old 11-10-2010, 07:46 AM   #3
60DRB's Avatar
Join Date: Dec 2009
Location: East L.A.
Posts: 1,138
Thanked 104 Times in 45 Posts

The grinding noise=sounds kind of like ice in a blender or sheet metal being dragged? That is from the IWEs not being fully engaged with the hubs on the front wheels.

The clunk, if occuring at the end of a "grinding noise" is the IWEs re-engaging with the hubs.

Possible causes are leaks within the vacuum system (to include the IWEs themselves) that operates the 4x4 on our trucks, or an intermittant malfunction of the solenoid that turns on/off the vacuum to the IWEs.

The good news is troubleshooting and repairing is relatively easy. These two threads are my "go to" sources for info on the issue.
60DRB is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
My 4x4 is acting all kinds of crazy....... aswrg7 2009 - 2014 Ford F150 13 10-07-2016 01:08 PM
Need help with P0022, P0354, and P0355 Chipadelphia 2004 - 2008 Ford F150 13 12-03-2015 09:36 AM
Why is my truck shaking while i drive? Jordan P Maintenance Shop 13 10-28-2015 01:49 AM
intermittent random grinding noise from front left KFWA 1997 - 2003 Ford F150 9 09-12-2015 01:43 PM
tailgate rattle on small bumps xtream 2009 - 2014 Ford F150 3 09-03-2015 11:50 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 09:33 AM.

Copyright 2006 - 2017 We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: