Gympie:

Sounds strange, you should never be before TDC under any circumstances, and if you are off the scale on the balancer, you have SERIOUS chain stretch! Make sure you have the correct marks -- I think they are on the top side of the cam and front tower on the DOHC six.

That timing chain guide is just the cat's meow -- fits over the gear with a slot in it, so both the new and old chains stay on the gear without human intervention. Makes the job a snap, Hans does 420/380 chain changes on the V8s by himself with it.

Pull a new chain through and check -- 12 degress of stretch is the rouch equvalent of one tooth on the cam gear -- it is possible that the chain is badly worn, but by that amount of stretch they usually break. I wonder is someone slipped while installing it last time?

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks again for your reply and advise Peter.

Yes, am pretty well astonished myself by how far it is off TDC! So much so I rotated the balancer 3 times and came-up with the same markings. I know which markings you are referring to. There is one on the intake and exhaust camshafts. Dunno how it could have gotten so far off. One tooth on the camshaft sprocket is about 18 degrees on the crankshaft. I’m about one tooth or excessive pin stretch.

When buying a valve wrench from Assenmacher Specialty Tools (AST) in Boulder, CO; the clerk told me about the chain guide. He highly recommended it for a chain roll. Will take a drive that way tomorrow and pick one up. The $50 for it should offset the time used without it.

What do you think about changing the guides?

Off to the Bronco game…………

Check the guides for wear. If the are plastic and brittle, get new ones, for the top, the bottom ones are a ***** to change. If they are metal and rubber, only replace if they are obviously worn (rollers touching the rubber).

Good luck -- I'll bet the running problems go away when you get the cam timing correct!

Check valve timing when you reset the cams, and check minimum valve clearance, just to be paranoid!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Just got on and read the whole story. That is a lot of stretch in the chain and it is almost more plausible that it is off a tooth. How far is the tensioner extended?

FWIW, Herr Fuchs, my go-to-guy on such questions, advised against replacing the tensioner, since it is a rachet type and should not wear out. I believe that you need to compress it when you install the new chain.

While you're at AST, don't forget the little slide rail puller kit you will need it to replace any of the sliders. They have a cute little one that works by turning a bolt that is designed for tight spots.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

My thanks to you both for your help and advise.

Did a quick check before going to the game of the rails and what I could of the tensioner. The tensioning rail looks without much wear. Cannot tell how much the tensioner is extended. Don't how to measure that.

Plan to do a valve adjustment when complete with the replacement of the chain. Think this should be done as a matter of course. The manual calls to remove the tensioner and to replace it with a rigid tensioner. What is this? Can something else be used instead of a rigid type?

Saw that slide rail puller in the AST catalog looks like must have tool.

Took a trip to Assenmacher Tool today and came away confused. The counter person stated that on a 110 engine to do a chain replacement I would also need a Press Tool to assemble the master link. The price for this is around $230 bucks.

On the way back to Denver, stopped at a couple independent MB shops and Stu Rittters to get a feel for what they would charge for the job. Got prices from 300 to 650 bucks. Only one shop said I did not need the press tool for the job.

What you'all say?

Both the Haynes manual and the factory CD show the replacement with a master link that has a clip thingy for the back side, and do not mention the press tool.

BUT - the master link at *************** does not show a clip. It probably depends on whether you can still buy a master link with a clip.

The man to consult on this is Rusty Cullens at 800 741 5252. He knows everything about MB parts.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Thanks Chuck.

Sent Rusty an email Sunday asking about the tensioner have not received a reply to date. He must be pretty busy.

Have checked other WorldPac clones on the web and some show the link included and others no picture at all. Don't want to buy the tool as I would most likely only use it once. But never know, might as well go into the timing chain replacement business. Heard many 380's need replacing.

Oh, one shop yesterday said they run the chain thru by cranking the engine with the starter instead of turning the damper. Is this Kosher?

Rusty is not an email person - call him up!

I think the starter idea is great, especially if you had a foot-operated remote switch so you could use both hands with the chain.

Business plan:

Foot-operated remote switch
Link crusher tool
Dremel tool to grind old link
Chain guide tool
Tool to remove top slide rails
Good basic tool set
One-bay shop or set up to travel as subcontractor
WorldPac account for chains, rails, gaskets, tensioners

Specialize and undercut the regular shops - what a great business! You could do 4-5 a day with a little practice. No overhead, no receivables.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Sounds great! Maybe a franchise idea also. Call it "Just In Time". Will work on the business plan tonight.

Gympie:

Rent the tool or borrow one -- don't use a clip type master link, crimp one on. You can use a heavy sledge and ball peen hammer if you are handy, too -- all you have to do is swage the end of the pins on the "master" link so the plate cannot come off. Hold the sledge behind the link, in close contact, and peen the pins over after you put the plate on (after pulling the chain through).

Don't use the starter! Please! If the chain goes too far and falls down, you have to do major work to get it back up (and, this, in fact, may be why yours is one tooth off), and on the V8s if you have a loose chain and crank the engine, you usually punch a hole in the front cover, necessitating head removal to get the cover back in and sealed, also must remove oil pan. Use a wrench, doesn't take that long!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter.

Didn't think the starter method would be kosher. It would be fast, but yet limited controlability. Plan to do it with a wrench.

Still am puzzled about the "rigid" tensioner which the service manual states to use when taking out the normal tensioner. Any idea?

Will see if a double row crimper is available. The service manual also states to use the "C" clip master link although.

"c"-clip master link is only to draw chain through, replace with crimp when in place. Only the crimp link comes with chain, the master link is a shop tool.

I think the "rigid" tensioner is the ratchet type, not simple oil pressure type as the ealier ones were, and the diesel ones are. Allowed too much chain slap in the DOHC engine, was replaced early on by the ratchet type. Get instructions, it doesn't just unscrew like the oil pressure only types, you have to retract the pin and lock it against a spring (or it shoots out into the oil pan, I think!)

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter.

Not sure if the master link is crimpable or a "C" ring. Going to spin the chain later and see what kind of master link it has on now.

The rigid tensioner is a temporary tool which is installed after taking out the tensioner and before replacing the chain. It looks like a long bolt with a nut and tee handle. Guess it is to place a hard tension on the guide to prevent it from retracting while running a new chain. Can't think of any other reason to use it. It is then replaced by the "re-cocked" tensioner after the chain is installed.

If it is the original chain, it will not have a master link - you need to grind or file the pins to get it apart.

I have never understood the rigid tensioner either, since I put the gears on with the tensioner out. Maybe it is used to tension the chain when you are checking valve opening with a dial guage.

Do you need the info on re-cocking the tensioner? I think it's on the CD?

Do you have the 17 and 19 mm hex bit sockets to remove the tensioner?

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe