<HR style="COLOR: #d1d1e1" SIZE=1> <!-- / icon and title --><!-- message --><TABLE width="100%" border=0><TBODY><TR><TD vAlign=top>I am having a klank in the drive train under deceleration. Happens around 10-20 mph. 2000 Excursion V10 6 inch lift, 35 in tires 4x4

I have had the following done and still the same Klank
New Rear Drive shaft
New Ujoints (2times)
Slip Yolk serviced.
New Gears
New Carrier Bearings
New Seals
I was told by one of te driveline people that it could be the transfer case chain? Has anyone heard of that being an issue The X has 97K miles

Thanks
</TD></TR></TBODY></TABLE>

 

I had a very similar issue in my truck. I have an 03 F250, 8" lift, 38s,4X4,5.13 gears, 90k miles. It began at about 30k miles, which was 5k miles after the lift was installed. My clunk, however, was always from a dead stop and clunked after the truck began to roll. And it also clunked after I came to a complete stop again. Occasionally it would clunk under heavy acceleration while the truck was at about 20 mph. The strange part about my clunk noise was that it was temperature dependent. It was only detectable at 60 degrees F and above and was worse the warmer it was outside. So that is the setup for the clunk I experienced. Over the course of 60k miles, I took my truck in around 8 times to see if anyone could fix it. I was told it was potentially<O></O>
1. backlashing in the gears<O></O>
2. transfer case chain is loose<O></O>
3. carrier bearing is bad<O></O>
4. seals<O></O>
5. u-joints<O></O>
6. driveshaft length<O></O>
7. drivetrain angle where it connects to the rear diff<O></O>
8. the limited slip in the rear diff<O></O>
<O></O>
So, I've had seals replaced, backlashing checked, transfer chain checked, carrier bearing replaced, u joints inspected (they were fine), friction modifier added to rear diff. I even found a link on this site that did a walkthrough of "superduty driveline clunk." It described that all superduty's have or will have a clunk due to a dry slip yoke. So, I took it in to get that serviced. Nothing worked. It has been infuriating. I finally got pissed off and decided to try lubing the slip yoke myself as per the instructions. Well, I soon realized that the pictures the guy posted were backwards from the way my driveshaft looked. Upon further investigation, I read that some superduty's had the driveline installed backwards. I don't know if his is backwards or if it is mine, but I stopped following the directions at that point. I took the entire driveshaft off from the front of the truck to the rear diff. I quickly discovered that when I took my truck to have the slip yoke serviced, they never did it. So much for Ford service. I got a big tube of grease and slapped it on the slip yoke, lined everything back up, and bolted it back on. I really didn't think that what I had just done would fix the problem. But, I started my truck up and drove it around and couldn't have been happier! I have clunk free driving now. It has now been two weeks since I have done this, and I haven't had a single clunk. Now, it might be the grease that fixed it, or it might be that I took the driveline off and changed the alignment ever so slightly. Whatever it was, 45 minutes of tinkering and a $5 tube of grease was worth the long shot of fixing such an annoying problem.<O></O>

 

I think I need to do that.. How long did it take you to pull the shaft and grease the yolk....

 

OK I found out what the clank was. During braking the pads would shift up and hit the top of the caliper. I replaced the hardware and serviced the brakes and wala no more clank/klunk. Even though it sounded like it was under the truck it was the drivers side brake hardware........

__________________