Rear End Clunk when D to R

[A K]

Edit: I should be clear with the category--it's not with the 4WD system. It occurs in 2WD.



Occasionally, the rear end will clunk when I go from D to R. It's repeatable, but not always. On my old Explorer, the rear end developed a clunk at about 80,000. I'm only at about 42,000 on the '04 ST, though.



It has to go in for a diffy fluid flush (and a few other things). Should I have them check the U's? Or what are the other common causes of a clunk?



Thanks, folks.

 

[Ray McIntireJr]

I was gonna say check your u-joints but ya beat me to it.

 

[Dingo]

That's exactly why the regular Exploders have the mysterious phantom 5th shock absorber.

 

[Ray McIntireJr]

5th shock absorber? Never heard of it.

 

[Dingo]

Runs from the passenger's side frame rail to the rear diff.

 

[Bill Barber]

Was supposed to be a stabilizer, most people removed them as they did nothing.

I think they stopped using themabout 10 yrs ago.

 

[Todd Z]

Ford buys their rears from some one else, For some reason they run high backlash, Allways causes pinion to ring slop....



Both my STs do it..



Todd Z

 

[Johnny O]

Both Rangers I had before did that. The dealer replaced the rear driveshaft on both with an aluminum unit on warranty which fixed the problem. Johnstone has the Ranger unit on his Sport Trac so I guess it will fit. You should be able to find one in a junkyard if you look a bit, get the aluminum unit, not the steel one.

Also simply removing the rear driveshaft, spray the inside of the slip yoke with brake cleaner, and re-lubing it has been known to fix the problem. The slip yoke simply dries out. Try that first.

 

[Todd Z]

I have the aluminum d/s in my 03 and the steel one in my 04



Todd Z

 

[Kevin Lang]

Doesn't aluminium fatigue under stress though? Airplanes have to have the metal maintained as its strength degrades under stress, unless they want to repeat the incident where the stewardess was sucked out.



Isn't that a bad thing for your driveshaft to be made out of? I've been curious about that for a while.

 

[A K]

Well, it looks like I better block off a week for this--depending on what the dealer wants and doesn't want to replace.



Thanks folks.

 

[Todd Z]

Kevin,



Most racers use solid aluminum shafts... I have run them for a while and as long a s there is no significant heat, they last just as long as the steel ones..



The drive shaft has no tension or compression just torsional...



Todd Z

 

[Johnny O]

It's not like a Trac puts out 500 hp to a pair of slicks. The hi-perf Mustang driveshaft from Ford racing is aluminum. The aluminum driveshaft on my Rangers was fatter than the steel one it replaced.