3.0L Cam Position Synchronizer "squeak"

[ptf18]

Replaced the Cam Position Synchronizer with a Motorcraft unit p/n DA 2089 as the OEM unit (with 245K miles on it) had been "squeaking" at start up for sometime. I had heard an occasional "squeak" for many years (its a '02 Edge, bought new) and had purchased the new unit some years ago never thinking of the possible problems I could of had by not replacing it.

Anyways, all went well with the replacement.

What I would like to know is why I can't get the old unit to "squeak" now that I have it out and on the bench? The thing looks like new. Doesn't seem to have excessive axial or radial play in the shaft. The gear teeth look like new. Try as I might when spinning the shaft, I can't get it to "squeaking".

Thought?

 

[RonD]

Its the bushings that wear out and squeak

At idle synchro is spinning at 50% of crank RPM, so 800rpm idle means synchro(can) is spinning at 400rpm, so you would need to spin it at least that fast if not faster to get the squeak
Cordless drill can do up to 1,500rpm, full speed "drill" mode

Odd thing is, the 3.0l distributor(1991-1994) used the same bushings and never had an issue as far as "the squeak"

 

[ptf18]

Does the synchro actually have bushings in its housing?

 

[pjtoledo]

yes.
on the bench there is no side loading, hard to get it to squeek.
in the engine the drive gear adds a side load so the shaft can rattle around if the bushings are worn.
at the top does the shaft move any at all side to side? that's where the problem starts.

 

[ptf18]

pjtoledo. I examined the syncro closer and found that there is axial play with the shaft. "Wiggling" the gear end of the shaft caused the upper portion of the shaft (the part with the "tab" on it) to move axially a noticeable amount.

Anyways, I ran the engine and no "squeak" at cold start up as there had been.

Now to change out the 3 O2 sensors with 245k on them.