I checked thru alot of older posts for tips on this subject, but didn't find what I need to know. First should I pull all the injectors so the motor turns over easy as I pull the chain in, or just leave them in. I had the timing adjusted last year--guess I'll need to redo that also? Anything I need to know to make this job a little easier? I got a estimate for $530 for the chain, and tensioner replacement. How does that sound to you guys--It sounds a little steep to me. Thanks

__________________
1990 300D 2.5
1991 F350 7.3 Dually IDI

1997 F350 gasser dump
1980 H-D 93 inch Shovel
2000 SE Roadglide

Yes,much easier.

[EDIT: For $500.00+ USD are condums and KY included,
or do you have to supply your own?]

(Make sure you observe SURGICAL cleanliness precautions BEFORE you begin)
['Stuff clean (LintLess) rags in the Injector holes to keep dirt out]
['Cover the I.P.'s Delivery Valve Outlets so nothing can fall in]

If you remove the Vacuum pump and replace it with the "Assembly Basket"
PN 601 589 05 14 00 [07?] the Timing Chain will not "Jump" when you take
pressure off of it.ALSO the FSM wants you to use a "Chain Retainer"
PN 602 589 01 40 00 to lock the chain down whilst you De-Rivet.

When you remove the Timing Chain Tensioner ,use the BIG outer Hex nut.

I'd "Tie Wrap"(Zip Tie,Whatever You Call Them) the Timing Chain to the
Camshaft Sprocket ,EXCEPT for the Topmost Links...which you plan to
use as entry ["Break" with the Special De-Riveting Tool]...'Detach your
Top Link...Attach the new chain to the old (It's a "Temporary" until you
pull the new chain "Around")
NOW Here's the only tricky part...You want to maintain tension on both
the old chain and the new...so you don't "Loose a Tooth"(or two or three)
If you use this method...now's the time for your "Helper" to clip the
Zip Ties whilst you maintain tension on both chains AND PULLING THE
OLD CHAIN OVER ACROSS THE TOP OF THE CAMSHAFT SPROCKET
from left to right (As you look at the front of the engine)...
(You're maintaining that all important TIMING) roll in the new chain.
When you've got the tail end of the new chain up to the Camshaft
Sprocket "Zip Tie" both ends of the new chain to the Sprocket so
you don't loose TIMING while riveting the Master Link together.

__________________
'84 300SD sold
124.128

The guy who gave me the estimate is the only Mercedes specific mechanic around. I knew I would get hosed, but to what degree I didn't know. Thanks for your help--I'll let you know how it goes. maybe some pics.

__________________
1990 300D 2.5
1991 F350 7.3 Dually IDI

1997 F350 gasser dump
1980 H-D 93 inch Shovel
2000 SE Roadglide

What made you decide that you needed to replace your timing chain? I've got a 90 2.5Turbo, and she's running rough, but I'm going to tackle the injector replacement first. 150k on the motor.

I have about 235k on the motor and don't know if the chain is original or not. I'm assuming it's original, so to be on the safe side I'm going to replace it. Can someone tell me if the OE chain has any stamp marks, like the MB logo, so when I pull the valve cover I might be ale to tell if it has been replaced?

__________________
1990 300D 2.5
1991 F350 7.3 Dually IDI

1997 F350 gasser dump
1980 H-D 93 inch Shovel
2000 SE Roadglide

Ordinarily I let chain stretch tell me when to replace a chain but in the case of an early 124 2.5, I wouldn't take chances even if cam timing is spot on. gsxr shared several times the technical details on which 602s were subject to timing chain problems. Since that's my motivation for replacing the chain, I'd replace the cam sprocket at well. The couple of 602 sprockets I've seen had very worn (pointy) cogs.

Borrow or rent an A-B timing light throught the tool rental forum to remove the guesswork from setting IP timing.

The upper pin holding the guide rail between the IP and cam can be a bear to remove and reinstall. The proper pin removal tool works better than stacked washers but is of no help putting the pin back in place.

If time is not an issue and replacing coolant is on your to do list, pull the radiator for maximum elbow room. Put a stiff sheet over the evaporator to protect it. Or over the radiator if you leave it in place.

Even with no cylinder compression rolling in the new chain is not very linear. The vacuum pump provides an overcenter feel. You'll turn the crank to feed chain and not much will happen. Then you'll hit a point at which the engine will swallow a foot of chain.

Sixto
87 300D

Yeah - the vac pump makes you freak out, since after it swallows that foot of chain, you're turning the crank for a while with no chain being ingested. Scary stuff. I'd almost consider removing the vac pump to eliminate this behavior. On the 602, the radiator can stay in place, there's plenty of room (it's tighter on a 603). No need to replace the sprocket if it is ok visually, same for the upper guide rail, although the rail is pretty cheap (the sprocket is not).

Definitely will need to check and re-set the IP timing afterwards, as the new chain will advance IP timing by about half the amount the chain was stretched (i.e., if chain was stretched 4°, IP timing will be advanced approx 2° with the new chain). Either rent the A-B tool if possible, or buy the OE/dealer lock tool (NOT the aftermarket lock tools on eBay, or anywhere else!).

Click here for the TSB which shows how to measure chain stretch. Click here for the FSM procedure on replacing the chain. It would be nice if you could borrow or rent the proper chain link crimp tool, but others have CAREFULLY used a hammer & dolly to peen the ends over. The OE master link with pressed-on center plate will be tougher to install without the proper tools. I'm not sure if the aftermarket/OEM links still have the slip-fit center plate.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

I'm going to do the chain as soon as I can line up a crimper and a-b light timer to rent at the same time. Also waiting for it to warm up a little. At least above freezing. And I want to thank you guys-Compress, Sixto, and Gsxr. You guys have helped me out more than you know with my 124.

__________________
1990 300D 2.5
1991 F350 7.3 Dually IDI

1997 F350 gasser dump
1980 H-D 93 inch Shovel
2000 SE Roadglide

You can..........it's in the rental pool.