I have a new 2003 E350 Econoline 4x4 van. At about 900 miles the van began making a loud "clunk" when engaging in reverse. My Ford dealer replaced the rear drive shaft (shaft from Quigley Motor Co. - the 4x4 converter) same result.

There is no clunk when going into drive - just reverse. The van now has nearly 7K miles on it, and the clunk is still there. It is no louder than before, but still definitely there.

Quigley thinks it may be the transfer case, and has sent one out for warranty replacement. (They are real quality folks at Quigley).

Any ideas? Thanks!

 

My F-350 clunked in forward and reverse. I fixed it in about 45 minutes after reading this:
http://www.eurekaboy.com/f250/slipjoint.htm

Hope this is it.

 

Add ford "teflon" grease to the splines of the output shaft and yoke

 

Many thanks for the excellent ideas. I will have the 4x4 shop grease the splines of the output shaft and yoke.

Do you know what the actual name is of the Ford "Teflon" grease is... or better yet the part number?

If I can't get the Ford "Teflon" grease... is there another grease that would work just as well.

My installation is on Monday morning, so I don't have much time to get the proper lubricants.

 

WHile i've heard the shaft splines can cause this problem, what about it being a rear end noise? What I would do is chock the wheels and see if someone can listen from under or the side and see if they can pinpoint the noise. It could be the pinion hitting the coast side of the rear gears on reverse application because the lash is too high (ie the rear was originally setup badly). Especially since a new drive shaft didn't fix the problem and probably came lubed properly.

Chris

 

The part number for the greatest grease made is:

D2AZ-19590-A

NAME: LUBRICANT - TEFLON GREASE

NET CONTENTS: ONE POUND

It is pretty spendy(I think about 40-50 bucks) but it is the best stuff for driveshafts, window regulators and any where else that needs a lubricant that can stay put even around moisture. One can will last you a long time.

 

Ponyracer

Many thanks for the specifics. I will get some today from my Ford dealer.