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The Case of the Missing Friction Washers

6/2/2012

 
Made a weird discovery today.  The front and rear friction washers that bookend the crank sprocket assembly on the Duratec are missing.  As a modern "dispose when done" engine, Ford/Mazda optimized for assembly line speed rather than rebuild ease, and opted to use clamping force to hold the crank pulley and sprockets in proper alignment, rather than a woodruff key.  These missing washers are paper thin, Porsche priced items ($20/ea) and apparenlty form a critical component of the clamping design.  

I don't recall replacing them when I did the cams in 2007.  I'm not sure if I
simply didn't know about them back then, or if I was told that they didn't  require replacement.  Now I suppose I could have simply screwed up and failed to  put the front washer on 5 years ago when attaching the crank pulley, but in order to get to the rear washer, you have to remove the oil pump sprocket and then slide it and the crank sprocket off the nose of the crank as a unit (there is virtually no slack on that chain even when the tensioner is removed).  I am absolutely positive I didn't touch the oil pump 5 years ago, and given there is no reason to remove the crank sprocket unless you're removing the crank  or replacing the rear washer, I can't imagine I would have taken it off, removed  the old washer, and then put it back together wihout a new one.  This tells me  that these washers were never on my engine.

As to why they were never there, I suppose it's down to the engine's
history.  It was purchased from Kansas Racing Products who manufactured  alloy racing blocks for Ford who in turn gave them sweetheart deals on excess engines. I was told these engines become available for a variety of  reasons: over production, pulled from the line for Quality Assurance testing, or  simply for the engineers to look at and measure. Because none of these engines  are considered “new” Ford can’t resell them as crate engines, so they are stuck with two options: destroy them or allow their “friends”  such as KRP to resell them at deep discounts to their own customer base.  When the engine arrived, the  coil pack mount was missing a corner, but other than that it looked brand new  and had never been fired.  Perhaps there was an issue with the washers on the  assembly line that was dioscovered after the engine was assembled, and it was  deemed cheaper to sell it (and possibly others) as an excess engine, rather than  repair it.

Between this and the cam bolt issue described below, I really dodged a
bullet.
GREG
6/6/2012 08:12:36 am

those nasty little washers are diamond-coated to increase friction so's the sprockets do not slip - that's why they are lunar-orbiter grade prices

tooth's sheaf stout is also an adequate dring - actually more suited to triumph and ducati motorcycle riders

Anton
7/28/2012 04:56:27 am

I have disassembled a 2.3L engine from a 2006 Mazda 6 recently and was also surprised to find no friction washers present on the nose of the crank. The official Mazda workshop manual also does not make any mention of fiction washers in this location. The washers are also not on the parts list of my local Mazda dealer. Friction washers are present behind the cam sprockets though.

The official Ford workshop manual for the 2L engine as fitted in the Fiesta ST does show the presence of two friction washers on the nose of the crank but none on the cams.

I know that the MPS (Mazdaspeed in the US) engine also has these washers on its crank.

BTW the 2.3L was still in an excellent condition after more than 100 000 km then I opened it up. I’m busy preparing it for boost. I am going to put the engine back together with friction washers on the crank and cams.

Howard
1/15/2013 08:26:05 am

I'm in the middle of changing my timing chain on my 2003 2.3L DOHC Ford Ranger and I only found 1 of these washers behind the double cranshaft pully gear. I went to Ford parts store and their parts system shows that 2 are needed for front and rear. I have no idea where the front one went. Mabey it broke and disintegrated.... I have no idea. Also I noted that the rear washer was not perfectly straight. The side that touches the cranshaft is slightly bent out from wear and the the crankshaft looks like it is worn. Makes me wonder if this washer has been cutting away at the crankshaft after so many years of spinning. Each washer is around $20 from ford.


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