I removed the vacuum pump, which was replaced about 5,000 miles ago. I noticed the timer cam was not perfectly smooth. See photos. Should I replace this? The wheel on the vac pump still lookks ok. I was thinking of using some fine emery cloth and cutting oil and trying to polish the timing device cam.

Attached Thumbnails

     

GSXR's pictures (For your comparison Purposes)
I'm sure you've seen his post on (Almost)Catastrophic VP failure?
http://www.peachparts.com/shopforum/showthread.php?t=231260&page=4

I'm already scared to death of my VP Cam interface.

Pierburg and Mercedes would probably say replace.

opinions much more expert to follow ,shortly.

(It sure looks like something other than the VP roller has been interfacing with
the Cam? Did you encounter any "Stressful" actions removing the VP that would account for the Imperfections on the Cam?)

Attached Thumbnails

 

__________________
'84 300SD sold
124.128

Virgin (As In still in box)
For your comparison:
('Wish I knew WT* I was doing Photographically,Shot these through a Magnifying Glass using ZOOM)

Attached Thumbnails

       

__________________
'84 300SD sold
124.128

(Once again forgive the photography)

Timing Device with 10K wear on it.

Attached Thumbnails

     

__________________
'84 300SD sold
124.128

I don't think any wear or gouges occured when I removed the vac pump for inspection. My previous vac pump failed and disintegrated. I suspect any wear to the timer cam occured before I removed the new one. Since the timing device cam "rolls" the roller instead of scraping it like a camshaft lobe/lifter relationship, I believe I can "polish" the timer cam enough to drastically reduce wear on the roller. It appears to have a sort of "scalloped" wear pattern on the surface of the timing device cam. Even the photos of a brand new timing device appear not to have a very smooth surface, as compared to other machined surfaces on an engine. Emery cloth will do a surprisingly good job of smoothing a metal surface, with patience.

Are you going to "Polish" it in place?
I'd be tempted to expose the process to a very strong shop vac to reduce the
probability of any swarf falling down into the TC cavity.
(rags stuffed into the cavity under the Timing Device ,first of course.

In Hindsight, after looking at the old pictures I took of the slightly used TD
mayhaps yours doesn't look so bad...

I'll see what I can do to make the 186,000 mile Timing Device visible sometime
this weekend.'should give a better comparison.

In comparison your Roller has a definite Burnished (Polished) appearance VS
the "New" roller

I am coming to believe the "Ramps" on the TD have less Brinell (Hardness rating) than the Roller on the VP.

[I 'll tell you what,I'm going straight to 15W40 Synthetic after seeing these.]

__________________
'84 300SD sold
124.128