I have a 1993 300 D. I found an external coolant leak in my head gasket so pulled the head and it is currently at the machine shop. To cut a long, painful and slightly embarrassing story short, (I couldn't get the timing chain guide of - I ended up cutting it apart), I moving the timing chain with a number of revolutions of the crank shaft. I am pretty sure that the timing chain, which I held with my hand as I turned the crank shaft slipped on the injector pump sprocket. So how do I make sure I have everything lined up properly? I know that my chain was 1 degree of Top dead center before I pulled the head. How do I make sure that the injection pump in synced correctly? Help greatly appreciated.

 

Here is a site that you might want to look at:
http://www.ps2cho.net/downloads/MB%2..._603index.html

I would pull the Fuel Injection Pump off. Insatall the new timing chain and follow the instructions to re-install the Fuel Injection Pump.

There is a Fuel Injection Pump Locking pin that is sold on eBay for about $28 plus shipping to lock the IP in position as you re-insert it into the Engine.
I am not sure the Locking pin is a replacement for timing but it will get you in the ball park.

 

I am trying to add a pic of the Locking Pin

 

Ah, thanks. So as long as the crank is at 15 degrees ATDC and the lug of the governor is visible in the hole where the locking bolt is screwed in, then the crank and the injection pump are pretty closely synced.

I think I will try to line these two up without removing the injection pump as I have a very loose timing chain and can spin the injection pump cog without moving the crank shaft. Do you think this should work?

 

Diesel 9112, thanks for your comment and the image of the locking pin. I opened up the bolt whole where the locking pin is installed. I found that when I lined up 15 ATDC, the pin showed correctly. When I turned the crank shaft 2 full turns it showed up again. This was hard to do and required a strong light and a little mirror to see into injection pump. I think I could see clearly!! I take from this that the crankshaft and injection system is aligned correctly. This brings up a couple of questions.
1. Using Murphy's law, if I could of screwed up the alignment I did, can I assume that with the head off I cannot un-align the crank and injection pump no matter what I do? Can someone who has rebuilt one of these engines confirm that the timing chain could not slip between the crank and the injection pump?
2. When putting the cam shaft back on, I will align the cam shaft with the crank when it is at 0 TDC (actually 1 degree BTDC due to chain stretch). This is the same TDC as the 15 ATDC that I align the injection pump with? Obviously the injection pump will only be correct for every other turn of the crank shaft, or fuel will be injected during the compression cycle. So which TDC do I align the cam shaft with?
Thanks for the help. I really don't want to bend any valves or have to break down the injection system again cause I aligned it wrong!!!

 

I am not sure what to say about this because when you do these sort of jobs it is best to line things up before hand and leave it that way until it is time to assemble them.

Rotating the Crankshaft only gave things a chance to shift some.

Since under normal circumstances the Camshaft timing is set at TDC and the Camshaft Drive Gear Installed. If it has to go back on at the 1 degree of retarded timing due to the Chain stratch so be it.
You would need to make sure that everthing is oriented so that the Fuel Injection Pump timing will be coming up next for the 15 degrees after top dead center if your rotat the Camshaft a little more (assuming you are looking through that Fuel Injection Pump hole at the timing mark inside).
I am not so sure how accurate "eyeballing" the IP timing mark with a mirror is going to be. But, it could be close enough if you are going to re-time the IP after the Engine is completely assembled.

I am also not sure what happens when the thinner head is installed and the distance between the Crankshaft Gear and the Camshaft gear is now closer. I know the Timing Chain Tensioner will take up the slack but I am not sure what effects this has on the Degree on the Crankshaft Damper that will be pointed to when the Camshaft Gear is aligned with the Timing Mark on the Camshaft Bearing Cap.
So I would like to hear back on that.
I am guessing that shaving the Head might retard the Camshaft timing a little more (assuming the same thickness of Head Gasket).

 

If you still have the head off it is a good time to replace the timing chain. Just my two ¢

 

There is a yes and no to the above.
If he mearsured the Timing Chain Stretch Correctly he said it only had 1 degree of stretch; indicting plenty of life left in the chain.
On the other Forum I hang out at a few members have said their timing chain failed within a month or 2 after replacement; a few others said afther 1-2 years.
They do not know if it is due to inferior aftermarket chains or improper installation (with the special chain crimping tool) or a result of wear on the Gear Teeth or other parts. But, it is clear that the factor instlled chain will last a long time if the oil is changed on a regular basis.

 

I am a strong believer if it ain't broke don't fix it. This is lesson hard learned! In the case of the timing chain, the fact that my car has 180,000 miles on it suggests the chain was replaced at some point. With such little wear, I see no reason to add the cost, time and the chance for me to mess something else up (As I said, lesson hard learned)!

I just got the head back from the shop, including parts, $900. Ouch. I guess I own a Mercedes. There was a crack, but I was hoping to get away with under $600. Oh well.

 

I think mine has jumped time. It is about 5 degrees before top dead center. This could be my problem no? Would that not make the fuel injected too soon, henze the loud diesel clang?