Timing cover replacement crisis E320 1995
 

I am having an upper front timing plate crisis.

have my e320 head back on and am stuck trying to get the timing belt top front plate back on. Playing with it for half an hour and I am thinking there has to be a technique to this that I am missing. I can get the top of the plate but the bottom will not go in. The pin for the drivers side chain guide is back into the head where it should be. I just do not get the physics of getting the bottom part of the plate in. I cannot even get the bottom part of the plate in at the expense of the top part. All I can think of is the pin on the drivers side down low. I am pretty sure that is stopping me. I'll get some pictures posted but I am sure that you folks know exactly what I am dealing with if you have been here and done this.

Thanks very much,
Jim Lee
1995 E320

This job is much easier if you remove the chain guide pin and then re install it after you have the upper chain cover in place. Removing the pin allows you to get the cover much closer to the head prior to engaging the alignment pins. As a result, the cover will already be on top of the u shaped seal instead of in front of it. Makes it easier to push the cover into place without rolling the u shaped seal. The chain cover has an access plug for this very purpose. Be sure to put an oil film on the bottom of the cover to help it slide over the u shaped seal. If you still can't get it to go in place, you can file a very slight chamfer on the bottom of the cover. (If I remember correctly, this is described in the service CD.....be carefull, you don't want to file to much)

Hope this helps.

J. M. van Swaay

Chain guide pin definition
 

Thanks very much.
Is the "chain guide pin" the one that I was referring to at the bottom drivers side?

I am not looking at the car right now but does this mean that you can insert that guide pin AFTER putting the cover on?
"The chain cover has an access plug for this very purpose."

Everything else is going pretty well as far as I can tell. This is my first Merc head replacement. Just trying to button everything back up.

Thanks very much,
Jim Lee

My Error
 

See pictogram in reply #10

Yes, the pin can be installed after the cover is in place. The hole in the cover probably will not line up exactly with the hole in the chain guide, but the tapered end of the pin will be enough to "self align" the holes as the pin is advanced. (if not, you may have to use a drift pin or similar tool to slightly position the chain guide....)

You probably know this already, but be sure to reinsert the chain tensioner plunger to the first (most slack) postion before reinstalling. Failure to do this could result in snapped off camshaft ends and or other very unpleasant problems.

J. M. van Swaay

Thanks all.
The chain tensioning plunger was going to be my next question.
I removed it no problem. Made sure I put the plunger back in and I could not overcome the spring pressure to start the threads on the smaller thing that goes behind it and keeps it in. Tried to do it on the bench and still no luck. Things went flying. Even without the spring I could not get the plunger to lock in anywhere. Finally lost the washer or whatever you call the ring that is supposed to keep the plunger ratcheted. The only way I was able to get the plunger in was to start threading it and THEN putting the entire tensioner into the engine. So as far as I can tell there is NO ratcheting going on at all. I am thinking of playing it safe and buying the little washer thing that is supposed to provide the ratcheting from ******** and the little 'bullet' looking thing that I also seem to be missing. I'll see if I can find a parts picture to be more accurate.

I think I get the deal with putting the timing cover on WITHOUT the guide pin being in place now.

Thanks very much,
Jim Lee

Just looked at the picture posted above--it doesn't look right. I think that is the bottom chain cover. Here is the picture of the top. Chain guide pin access hole is number 44.

J. M. van Swaay

timing tensioner anxiety
 

Referring to Steve Brothertons excellent article he writes:

"Installation involves putting the body of the tensioner back first, with the chain and cams timed. Then install the plunger, spring/spacer and end cap. The act of installing the spring will push the plunger into the chain tensioning rail. If it doesn't, it is because the clip/ring isn't starting in the ratcheting bore. In this case, tap the piston/plunger with a punch to start it in the bore. A distinct tap will do it, whereas the constant pressure of the spring may be more than your hand can handle. "

The "clip/ring" he refers to above is missing for me.
And even when I had this clip/ring I was not able to tap anything in to lock it so that I could get the back part of the tensioner threaded after putting the larger piece back on.

Would it be possible to replace this at the hardware store? I am also missing the thing that looks like a 'bullet' that is shown in the Brotherton article. I would buy the entire assembly again but what I see at AutohauzAZ does not show all the pieces that I have.

Thanks very much,
Jim Lee

Timing cover picture
 

I am not finding the picture of the timing chain cover. I do see your gallery of fine Mercs.

Thanks,
Jim Lee

Sorry, technical difficulties with file types..... Here's the picture.

Tensioner tension
 

So 38 is the guide rail pin and it can be put in AFTER I get the cover plate on? Excellent. Now I just have to figure out what to do with tensioner. I would think that if I do not have the ratcheting thing working that I would definitely run the risk of the chain being too tight. Right now it is all together and in there with the direct pressure of the spring. I plan to visit the hardware store and see if I can get a 'clip/ring' that will allow this thing to 'ratchet' in like it is supposed to. I would be very depressed if I busted my camshaft.


Thanks,
Jim Lee

Getting the spring and spring cap installed can be a real bear. I found that by using a stubby ratchet drive I was able to get just enough push on the spring to enagage the threads. (be careful not to cross thread....) My fingers were not strong enough to compress the spring and turn the cap at the same time. Using the drive allowed me to use the strength of my whole hand. (again, don't cross thread as a result of not having the finger feel...)

As for the lost clip ring, I would recommend getting one from the dealer. The ratchet movement of the plunger is important, it provides proper chain tension at startup before oil pressure is available. Without this clip, the chain can have to much slack on a cold start. Don't know if it's enough to allow the chain to jump time, but why take that chance.

J. M. van Swaay

My (patent pending) technique for reinstalling the tensioner was to remove the air cleaner box for better access, and then position a long screwdriver under a covenient fulcrum point for leverage. Use the screwdriver to press up the bottom of the tensioner while screwing it in until the threads hold.