I want to put a new one in my 85 300 SD I heard Iwiss is the best where is the best place to buy and do I have to put new guide rails in and spring in tensioner?

What makes you think the old one needs replacing?

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

The minimum replacement seems to be the Chain itself, the large Chain Rail and the Tensioner Spring. (Replacing the larger Chain Rail requires that the lower Pin be removed and on the Turbo Models I believe you need to remove the Crankeshaft Damper to do that. A good time to replace a leaking Front Cranshaft Seal if You have that problem.)

It is a real good idea to replace the larg Tensioner Chain Rail because you don't want the New Chain trying to ride in the ruts the old Chain wore into the old Chain Rail.

Some people also replace the other small Rails as they are Cheap.

You should certinly inspect the Camshaft Drive Gear but the Manual offers no specs or pics to help you there.

The Crankshaft Gear is the one that does the most work but most people don't seem to inspect that or replace it.

In fact if you replace all the Gears and the Rails you are getting close to $500 in parts.


Thread on Timing Chain and Rail Has list of parts
Recommended Timing chain brand?? - Page 2 - Benzworld.org - Mercedes-Benz Discussion Forum

__________________
84 300D, 82 Volvo 244Gl Diesel

Here's a photo documentary of the process involved with my 300D turbo (same engine as yours basically), to give you an idea of what you should expect. The part numbers purchased were provided above in a related thread.

W123 timing chain replacement - photo references

__________________
http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

Skippy the reason I want to replace the timing chain is I own the car since 08 and did not know the maint. history on car when I bought it and since I probably put 50,000 miles on it an M.B. mechanic told me The chain should be replace soon after I bought it. I did not precisely measure the stretch in degrees on it as I did not have the proper dial indicator to measure it but I will do that soon. I'm hoping that by replacing the chain it will put my fuel injection timing more in spec. and make the car run better. I will do a lot more research on replacement before doing it.

Yuke,

Here is a good thread on replacing all the related parts and the chain, with pictures.



9 degrees of chain stretch

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Sounds like a big PITA to replace big upper rail and spring in tensioner.
Can I just take a chance and roll a new chain in and be done with it? Would I have to release the tension on the tensioner to do this. Is there anyone close to N.W. In. that could give me and hand with this job?

take a picture of the chain rail and post it here.
also, look at the thread on 2mm lift vs cam mark and do a quick and dirty chain stretch check. you may not need a chain. or you may need all the rails changed. the chain may already have an offset key in there, so after you check the alignment marks pop the cam bolt out, and look at the key.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

These chains are double linked. If you are going to do it, do it, do it right, don't half ass it. Rather than putting timebomb in your car, why don't you measure current stretch, pop the cam sprocket and see if there is an offset woodruff key.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Jinx!

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

On the Non-turbo Engine I guess it is possible to remove the Timing Chain Tensioner Spring and the Piston would slide out. That would remove the tension on the Timing Chain Rail.

If it is a 617 Turboed Engine you need to remove the Timing Chain Tensioner because there is what is called a Ratchet Device made into the Timig Chain Tensioner.
The short desciption is that the Ratchet device only allows the Piston to go one direction. That means you can remove the Timing Chain Tensioner Spring and the Piston is not going to come back out unless a lot of force is used on it; if it is possible to move it back at all.

Better to read up on the details of how to do it and make your own decision.

__________________
84 300D, 82 Volvo 244Gl Diesel

The main tensioner on mine still had a lot of material left on the rail itself, but you can see the grooves. The chain, main rail, and tensioner assembly are typically what is replaced when doing the timing chain. The PITA portion of the repair is removing the lower pin for the main rail (actually any pin, since they are in there pretty good).



The rest of the chain replacement is straightforward. Be sure you've fastened the master link in properly before buttoning her up. Use the correct tool for the job.

__________________
http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

I agree with MBeige.
I would not want a New Timing Chain trying to run in the Old grooves of the large Old Timing Chain Tesioner Rail.

I don't think that the other Timing Chain Rails do muich so I don't know how critical it is to replace them.

__________________
84 300D, 82 Volvo 244Gl Diesel

The other three brown hard-plastic rails are just guides to guard against chain slap.
--They do wear but not to the same extent of the main chain tensioner rail--That one should be replaced with the chain....

__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

I don't really believe the timing chain cares, however.

If there is abradable material remaining on the tensioning rail, the engine won't care either.