Another slant on a 617 crank issue. I have one of these engines torn down at the machine shop right now getting resleeved (see the thread about rebuilding a 300SD that I put up). About 8 months ago on this particular engine I installed a new timing chain. It had a problem at cold idle in the fact that it idled like crap. Anyway, after I rolled in the new chain I could manually turn the engine over and the cam mark would not line up the same everytime I cranked it over and there were still some issues at cold idle. Anybody want to guess what I found wrong that I suspect was causing this issue.

The woodruff keyway on the crank shaft was wallered out pretty severely. I will try to eventually get a pic of it. I am going to install my good crank out of the 617 engine I tore down about a year ago in the engine when I put it back together. First time I had seen one of these keyways in the crank wallered out like it was.

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Jim

The answer was there right in front of me!

Thanks again, Leathermang!

Now, if the crank snout can be retapped, the 240D can be resurrected.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

Let me know if you are unable to repair it. I have a good spare 240D crank in the shed I will sell for a fair price if you need it.

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Jim

Herb, Since you are in Houston... you should contact this group/join their club... and read their clubsite.... I am sure they are the type which will say " you will only have to replace the crank after our cold dead fingers are pried off our metal lathes"... LOL

http://www.homemetalshopclub.org/news/oct96/oct96.html

The are IN Houston... how lucky can YOU get ? I wish they were in Austin....

note the ' thread forming taps' on that page....

To be extra carefull you might want to use a starter tap and then a bottom tap....The starter tap might not clean up the last inch or so of threads....this is where the bottom tap will help as it will clean and redo the last inch of threads. This is what I would do....Jim

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James A. Harris

Mount the three cup springs (washers) with the crown (raised dome) toward bolt head.

The harmonic balancer is secured to the crankshaft by a single 18mm X 45 mm bolt torqued to 270 - 330 Nm = 200-244 ft. lbs.

I was told the dowel holes are NOT 180 degrees apart therefore the balancer only goes on one way. It was almost difficult to tell by eye because the dowels are like 178 and 182 degrees. The replacement dowel pins that I got were the wrong length, so they had to be ground down so that the three washers on the crank bolt did not bottom out on the dowels. I have heard of several others that also needed to grind down the dowel pins for proper fitment. Just noticed you have the 240d, I have a 300td (5cyl.) so I am speaking about that car...not sure if the 4cyl is the same.

This thread is only 7 Years old and still gets help . Hope he has it back together by now.