Hi -

I am contemplating a timing chain change on my 1989 560 SEL with 98,400 miles. I have been reading the posts here and am confused as to what to expect. I know from the service manual and from the posts here that I can do the change via the valve covers, i.e. no need to remove the timing case cover. However, will the guides on this model be plastic or metal, i.e. besides the timing chain, the valve cover gaskets, and the tensioner, what other parts should I purchase on the web before I get started? And am I being paranoid changing the chain now, or should I wait 20,000 more miles? The car is mint otherwise....

If it were my car I would change the three plastic rails (two in left head, one in right) and drive it another 100k worry free.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

You mean of course in addition to changing the chain?

You have already helped me by answering the one key item I was wondering about - that they are plastic rails in there, and that they should be changed...

Thanks!

Yes, the rails are plastic. The issue isn't with the chain, but when one of the rails break, as they become brittle with age/infrequent oil changes.

I know on my recent timing chain replacement, we also replaced the top chain sprocket (gear). The teeth were pretty pointed and non-uniform. This may not be necessary in your case, and you won't know until you get inside.

That's the benefit of having someone like Steve perform the work.
1. The deficiency was detected
2. The part was ordered and installed the next day
3. It only added ~$65 to the job because the tech was aready in there working.
4. Came with a full warranty.

For me it was $$ well spent to not have to worry the sprocket was going to accelerate wear on my new chain and/or lessen my driving enjoyment.

Steve ?? is this a common replacement item, or do you find the teeth are rarely to the point (ha ha) of needing replacement?

Not to disagree with Steve, but I had no idea if the chain was ever changed on my 560 (I bought it at 166K) and the chain I removed was very loose and sloppy. Laid out straight on the deck, if I lifted it up at the mid-point, I could almost lift it one foot of the deck before the ends lifted. That seems to be alot of slop. It has been mentioned before here that you can see the wear by holding a t-chain out horizontally on it's side - the V-8 chain is too long to try (trust me I tried) as it's 6 feet long. If you have no oil change history on this car, I'd be safe and change the chain anyway.

I do know the upper guides on mine had been changed as they were installed incorrectly. Should have one long and one short in the left head and another long one in the right head. I'd replace the guides before rolling in the new chain.

Parts: T-chain, tensioner, upper guides, valve cover seals. Plus, a new set of belts all the way 'round, since you'll have to pull them off anyway, and might as well change the power steering filter and fluid (although you don't have to drain or remove the pump from the car, just unbolt from the block).

An easy weekend project for an accomplished DIYer.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

What a great web site! I love the enthusiam and the honest advice.

I will do the chain and the guides. I'll let you know of my experience.

This is my first Benz. We bought it just two weeks ago as a second car (we have a TT roadster). I figured it would be a great classic sedan, stunning (black on black with red woodwork, mint overall), practical (large trunk, room for friends and family on visit), and overall reliable (do the maintenance, the block will last forever). I have worked on cars before as a hobby, and I can get the parts for a reasonable price. And it's from my home town! (Though I live in the states, I am originally German, and actually from Stuttgart. I'm not kidding.)

Make sure to pull rockers when doing the chain so it doesnt jump on you. After pulling the pins for the rails put a little sealant on the ends that go in the head (they leak sometimes). Check the sprockets and make sure they are not worn badly and replace oil rail kits while you are there>

__________________
euro 287
Mercedes Technician 7 Years (retired to Hyundai)
2000 Dodge Durango
98 Mazda truck

Check out this thread . It is a rather lengthy thread on some of the trials and tribulations I shared while resurrecting the 560SEL. I discuss the t-chain about halfway through, might be of some assistance to you.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

on the t-chain on the 560. Very helpful. I also bought the Benz CD with the shop manuals - first purchase I did after buying the car.

I figured it might also be a good idea to remove the plugs - makes the engine easier to turn with no compression.

When removing the rockers - Benz recommends this hugely expensive valve spring compressor to get the rockers out. Will a simple screw-type compressor do, or am I going to have to spend the $175 and get the tool from Samstag sales?

You need a compressor that will work around the cam.
The simple screw type needs direct access to the top of the
valve.
Definately change the valve seals and the oil supply elbows on top of the cam bearing caps. Mine were brittle and broke when I
gently pried them off, leaving pieces of plastic in the holes which
are a pain in the A** to fish out.
I'm just finishing up my 420. Read and re-read all the posts.
Pay attention to not letting the chain jump time.

Regards,

__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"