Marilyn the 240D's OM617 Transplant... - Page 3 - PeachParts Mercedes-Benz Forum

WVOPWRD! · #31 09-17-2014, 11:41 AM

Yes, I know that in part, it holds the timing marker, but I need to make sure that removing and putting it back in won't release something behind it having to do with some type of chain guide, rail, etc.

I'm hesitant to remove and asking because, rarely is there such a large bolt if its only job is to hold a little marker out there on the front...

WVOPWRD! · #32 09-17-2014, 02:11 PM

Maybe someone has an exploded view of the engine that shows whether that bolt has bearing on something important on the inside? Last thing I want is to remove it and hear something inside spriiiinngity-blop, ploosh blub...

WVOPWRD! · #33 09-17-2014, 09:15 PM

anyone????

ROLLGUY · #34 09-18-2014, 12:23 AM

Quote:

Originally Posted by WVOPWRD!

Maybe someone has an exploded view of the engine that shows whether that bolt has bearing on something important on the inside? Last thing I want is to remove it and hear something inside spriiiinngity-blop, ploosh blub...

I think it is okay. I remember removing that bolt on mine to clean around it better. I think there is an aluminum washer that seals it.....rich

Stretch · #35 09-18-2014, 07:53 AM

Quote:

Originally Posted by WVOPWRD!

Yes, I know that in part, it holds the timing marker, but I need to make sure that removing and putting it back in won't release something behind it having to do with some type of chain guide, rail, etc.

I'm hesitant to remove and asking because, rarely is there such a large bolt if its only job is to hold a little marker out there on the front...

Stupid size for the job it does

Quote:

Originally Posted by WVOPWRD!

Maybe someone has an exploded view of the engine that shows whether that bolt has bearing on something important on the inside? Last thing I want is to remove it and hear something inside spriiiinngity-blop, ploosh blub...

You might find something on google images but I think most of the cut away views ignore the bit you want.

Ideally it should be a blind hole - but it isn't...

Quote:

Originally Posted by WVOPWRD!

anyone????

...I'm pretty sure there's nothing on the other side being held on by that bolt

Quote:

Originally Posted by ROLLGUY

I think it is okay. I remember removing that bolt on mine to clean around it better. I think there is an aluminum washer that seals it.....rich

There was an aluminium washer on mine

funola · #36 09-18-2014, 09:05 AM

If the timing pointer and tdc sensor was disturbed, you have to follow the FSM procedure to retime it.

leathermang · #37 09-18-2014, 10:52 AM

Quote:

Originally Posted by funola

If the timing pointer and tdc sensor was disturbed, you have to follow the FSM procedure to retime it.

So the question is..... how do you tell if they have been disturbed ?
What is the checking procedure ?

DeliveryValve · #38 09-18-2014, 02:24 PM

Quote:

Originally Posted by WVOPWRD!

Hey folks, what is this big shiny bolt (upper left) attached to on the inside? Some part of the timing chain whatnots? I ask because it's leaking a small amount of oil from behind the bolt and collecting on the timing pointer, and I'd like to take the bolt out and seal the rim with some RTV, trying to have a leak free engine, and this is the only leak I've found now that the thing's been filled with oil and run for a minute...

That's no big deal. That bolt is like a drain plug. I just use oil/gas Teflon tape and tighten the bolt down.

As far adjustment, if I recall, there really is no adjustment other than bending the timing pointer. But I would note the position on the balancer before removing it.

Also as far as knowing if it is accurate? I don't know the FSM procedure, but I would pull the #1 prechamber and measure the piston height with a dial gauge. That will tell TDC and than adjust the pointer if necessary.

leathermang · #39 09-18-2014, 02:54 PM

Quote:

Originally Posted by DeliveryValve

.....note the position on the balancer before removing it. .....

Also as far as knowing if it is accurate? I don't know the FSM procedure, but I would pull the #1 prechamber and measure the piston height with a dial gauge. That will tell TDC and than adjust the pointer if necessary.

Seems like a good place to put a reminder of how to find TDC if other things have gone wrong... for instance... if a key has sheared on your balancer.. or if rubber on balancer has allowed the outer surface to rotate... I had that happen on a Dodge once... very frustrating ...

Questions involving I.P. timing.

"""
Here is one example.. in this case due to angle he used a method to hard stop the piston and then turned the engine backwards. something our engines do not want to have happen to them due to the long timing chain design... but the phsics are the same...as noted in the second post.. I am not making this stuff up...and it is not a matter of opinion...

http://www.mossmotors.com/forum/forums/thread/5744.aspx

""Finding TDC shouldn't be too hard. First you'll need a degree wheel and some type of pointer. This might be a problem if the engine is in the car, if so then you'll have to be a little less precise but you should still be able to get close. Remove the plugs and make up a piston stop from an old spark plug. I've done this by breaking out the ceramic insulator and drilling and taping the plug body for an appropriate sized bolt. Raise the piston on the number one cylinder to nearly the top, install the piston stop and adjust the bolt until it hits the piston, then lock it in position. Mark the front pully or damper at this point and then carefully turn the engine backwards until the piston hits the stop again. Mark this point. One half way between these two points is TDC. If you're using a degree wheel, then remove the piston stop, rotate the crank to where the calculated TDC lines up with the pointer and mark your damper. If you don't have the degree wheel, then measure between the two marks and mark the center. You should be close enough to be able to set the timing and tune that Prefect.""

""In theory it might work. I'm afraid though that with the piston right at the bottom, a movement of several degrees on the crank would make an all but imperceptible vertical movement of the piston. That's probably pretty much like Bill suggested at the top. Just a very small error in finding the exact top or bottom could lead to a several degree error at the crankshaft."""
__________________

WVOPWRD! · #40 09-18-2014, 03:18 PM

Quote:

Originally Posted by DeliveryValve

...But I would note the position on the balancer before removing it.

Also as far as knowing if it is accurate? I don't know the FSM procedure...

Yeah, I'll definitely just put the thing on a balancer mark and make sure it's there again when I reinstall.

As far as TDC being accurate, it does seem to be as I lined up TDC and the mark on the camshaft/timing chain sprocket, they're dead spot on.

SIDE QUESTION: Does this mean the chain has no stretch in it? Or just that the tensioner is still able to take up the slack?

Thanks for the help y'all...

leathermang · #41 09-18-2014, 03:45 PM

The chain has elongated. It does not really stretch... the contact points wear...and the accumulated wear shows up as ' stretch'.... wear happens much more with a new chain.. the first 10,000 miles will cause noticeably more elongation than from 200,000 to 210,000. Unless of course something like not changing the oil and filter or running low on oil.. or using the wrong oil occurs in ' later life '....

WVOPWRD! · #42 09-18-2014, 07:33 PM

Quote:

Originally Posted by funola

If the timing pointer and tdc sensor was disturbed, you have to follow the FSM procedure to retime it.

So at least pertaining to my situation, just wanting to take the thing off, seal it, and put it back on, there really is no need to mark anything or do any kind of re-timing, because that thing is held in only one place by a little pivot/stud/thingy in the lower right corner, and that oversize elephant bolt holding the top of it in, there's really no room for play. It just pops right back into place. I ended up using a small smear of RTV around the pointer assembly where it contacts the block, and using PTFE sealant on the threads. It was also only on by about 10 ft. lbs. which would explain why it was leaking in the first place...

funola · #43 09-18-2014, 08:59 PM

Quote:

Originally Posted by WVOPWRD!

So at least pertaining to my situation, just wanting to take the thing off, seal it, and put it back on, there really is no need to mark anything or do any kind of re-timing, because that thing is held in only one place by a little pivot/stud/thingy in the lower right corner, and that oversize elephant bolt holding the top of it in, there's really no room for play. It just pops right back into place. I ended up using a small smear of RTV around the pointer assembly where it contacts the block, and using PTFE sealant on the threads. It was also only on by about 10 ft. lbs. which would explain why it was leaking in the first place...

See FSM 03-345 Checking and correcting adjustment of TDC transmitter. It's a pretty involved procedure with dial gauges.

Stretch · #44 09-19-2014, 01:53 AM

The TDC pointer has no adjustment in it so the process of finding "true" TDC again is mute. There's bugger all you can do to change it. The FSM has no procedure for putting the whole bracket on. However funola's link to the slider on the bracket does have a procedure for adjustment.

I got all in a bunch about this procedure when I put my TDC pointer back onto my OM617 only to have it pointed out to me that at the top of the procedure for the slider adjustment it says it is only necessary to get anal about it if you are planning to perform dynamic timing measurements...

The tachometer sensor position is only then needed to be known with respect to crankshaft position (measured via piston height) - otherwise the tachometer sensor just counts the blips - giving out speed instead of speed and known position.

So to cut a long story short =>

Take it off - clean it up - apply some RTV if you like - bung on a new washer if it looks like it is worn - bung it back on - job's a good 'un