300D Timing Chain Replacement

1976-1985: 230T, 230E, 230TE, 230CE, 280E, 280TE, 280CE, 240D, 300D, 300CD, 300TD,
Post Reply
griffis
Ponton
Posts: 233
Joined: Thu 21 Feb, 2008 9:21 pm
Model you own: w123

300D Timing Chain Replacement

Post by griffis » Thu 05 Mar, 2009 4:59 pm

Just changed the timing chain at 475,000km on my 300D. Wow what an improvement. Quieter, better pick up & hill climb performance. I will monitor fuel/oil consumption and report on any improvements in this area.

Before I made the decision to replace the chain, I checked the chain stretch, using a dial gauge indicator - came out at 20 plus degrees on crankshaft pulley - should be 13.5 degrees.

Changing the chain is really a three person job - one to crank engine, one to feed in new chain while maintaining tension and one to pull on old chain (to maintain tension). It is possible with two people, but the chance of the chain slipping on the sprockets is much increased and then you have to re time the system.

Chain tensioner & guides all looked okay, so left them as is.

Sean

User avatar
John Green
OZBENZ Admin
Posts: 6344
Joined: Mon 20 Jun, 2005 4:49 am
Model you own: w124
Location: Canberra-center of the known universe
Contact:

Re: 300D Timing Chain Replacement

Post by John Green » Thu 05 Mar, 2009 8:52 pm

Remove the rocker arms and glow plugs and it can be done on yoru own, as there is no compression and the rockers dont just due to the cam it turns over very easy.
Save up to 50% on your Mercedes-Benz parts. Phone toll free on 1300 787 300

M.B Spares 14-16 Lyell St, Fyshwick ACT. Please send parts requests to spares@mbspares.com.au not via the forum messenger system.

http://mbspares.com.au

User avatar
Ivanerrol
Mercedes Demigod
Posts: 5494
Joined: Sat 12 May, 2007 3:21 pm
Model you own: w204
Location: Melbourne

Re: 300D Timing Chain Replacement

Post by Ivanerrol » Thu 05 Mar, 2009 9:48 pm

That go for petrol engines as well John?

Remove rockers and spark plugs?
W204 - C280
W202 - C180
W210 - E240
Departed
W202 - C200
W202 - C180 - On consignment to nephew
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

User avatar
Tony From West Oz
OZBENZ moderator
Posts: 3055
Joined: Mon 20 Jun, 2005 10:04 pm
Model you own: w202
Location: Bedfordale WA

Re: 300D Timing Chain Replacement

Post by Tony From West Oz » Thu 05 Mar, 2009 11:13 pm

John Green wrote:Remove the rocker arms and glow plugs and it can be done on yoru own, as there is no compression and the rockers dont just due to the cam it turns over very easy.
Don't forger the IP which needs significant torque when coming up to an injection point and twists to pull the chain when past the injection point.
If not prepared for it, this can cause the chain to easily slip one sprocket tooth.

With care, it is a one person job, just watch for sudden loading of the chain as it is fed in.

I hope this helps,
Tony
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

User avatar
John Green
OZBENZ Admin
Posts: 6344
Joined: Mon 20 Jun, 2005 4:49 am
Model you own: w124
Location: Canberra-center of the known universe
Contact:

Re: 300D Timing Chain Replacement

Post by John Green » Sat 07 Mar, 2009 8:21 am

That go for petrol engines as well John?
Each engine is slightly differant, but the basic principle remains the same. On the M116/117 V8's you can do it. On the M102/103 you can't remove all the rockers as they also hold down the cam, what I do with them is remove all except the No.1 rocker carrier and then wind in the chain. Aparts from stopping the engine from jumping it is a good way of checking the condition of the cam and rocker arms.
Don't forger the IP which needs significant torque when coming up to an injection point
Good point, but i/we did one only two weeks ago and can remember the pull of the pump as we wouldn int he chain but it was very minimal. Don't forget that there is that special bolt int he block to the L/H side of the engine that stops the chain from jumping on the IP sprocket.
Save up to 50% on your Mercedes-Benz parts. Phone toll free on 1300 787 300

M.B Spares 14-16 Lyell St, Fyshwick ACT. Please send parts requests to spares@mbspares.com.au not via the forum messenger system.

http://mbspares.com.au

griffis
Ponton
Posts: 233
Joined: Thu 21 Feb, 2008 9:21 pm
Model you own: w123

Re: 300D Timing Chain Replacement

Post by griffis » Tue 10 Mar, 2009 11:46 am

All makes for interesting reading/opinions.

I did remove my glow plugs. I never even thought to remove my cam followers. I still think that having three people made the job that much easier, safer(less chance of the chain jumping a tooth) & probably quicker.

One interesting observation - the new duplex chain has significantly thinner link joining pins, compared to the old original chain - any comments?

Sean

User avatar
John Green
OZBENZ Admin
Posts: 6344
Joined: Mon 20 Jun, 2005 4:49 am
Model you own: w124
Location: Canberra-center of the known universe
Contact:

Re: 300D Timing Chain Replacement

Post by John Green » Tue 10 Mar, 2009 1:16 pm

the new duplex chain has significantly thinner link joining pins, compared to the old original chain - any comments?
Umm, I have bad news for you. You have a sub standard non genuine chain.... The OE chain has the thicker pins to cope with the extra strain of the diesel and the unbalance of the 5 cylinders. It also has to be joined with a special tool that peens over the ends of a special link to make 100% sure it does not come undone. I bet your chain had a circlip style joiner?

There are quite a few products that I will only sell certain brands on timing chains is one of them, radiators and ignition leads are a few others. The associated risk of using parts like this is not worth the money saved.
Save up to 50% on your Mercedes-Benz parts. Phone toll free on 1300 787 300

M.B Spares 14-16 Lyell St, Fyshwick ACT. Please send parts requests to spares@mbspares.com.au not via the forum messenger system.

http://mbspares.com.au

griffis
Ponton
Posts: 233
Joined: Thu 21 Feb, 2008 9:21 pm
Model you own: w123

Re: 300D Timing Chain Replacement

Post by griffis » Wed 18 Mar, 2009 10:06 am

Hi John,

I was afraid you might say something like this.

As an ex bike rider I have no real issues with the clip joiner for chains. I have always found this method of chain joining to be reliable as long as the clip has the closed end pointing in the direction of chain travel.

The thinner joining pins are a worry. I will contact you for a price on an original specification chain.

Regards

Sean

User avatar
John Green
OZBENZ Admin
Posts: 6344
Joined: Mon 20 Jun, 2005 4:49 am
Model you own: w124
Location: Canberra-center of the known universe
Contact:

Re: 300D Timing Chain Replacement

Post by John Green » Wed 18 Mar, 2009 12:57 pm

The problem with the clip is the vibration of the diesel shakes them off sometimes.
Save up to 50% on your Mercedes-Benz parts. Phone toll free on 1300 787 300

M.B Spares 14-16 Lyell St, Fyshwick ACT. Please send parts requests to spares@mbspares.com.au not via the forum messenger system.

http://mbspares.com.au

griffis
Ponton
Posts: 233
Joined: Thu 21 Feb, 2008 9:21 pm
Model you own: w123

Re: 300D Timing Chain Replacement

Post by griffis » Mon 23 Mar, 2009 3:33 pm

Hi again John,

There should be no side thrust on the chain joiner link and the vibration from a reasonably well tuned 5 cylinder could not compare with the stress/harsh environment of a bike drive chain.

Sean

User avatar
John Green
OZBENZ Admin
Posts: 6344
Joined: Mon 20 Jun, 2005 4:49 am
Model you own: w124
Location: Canberra-center of the known universe
Contact:

Re: 300D Timing Chain Replacement

Post by John Green » Mon 23 Mar, 2009 5:42 pm

My knowledge of bike chains is zero, but do know of multiple cases of OM series engines that have had a chain link come apart when the circlip version was used. Maybe it is the strain caused by the smaller pin, who knows.
Save up to 50% on your Mercedes-Benz parts. Phone toll free on 1300 787 300

M.B Spares 14-16 Lyell St, Fyshwick ACT. Please send parts requests to spares@mbspares.com.au not via the forum messenger system.

http://mbspares.com.au

griffis
Ponton
Posts: 233
Joined: Thu 21 Feb, 2008 9:21 pm
Model you own: w123

Re: 300D Timing Chain Replacement

Post by griffis » Tue 24 Mar, 2009 12:36 pm

John Green wrote:My knowledge of bike chains is zero, but do know of multiple cases of OM series engines that have had a chain link come apart when the circlip version was used. Maybe it is the strain caused by the smaller pin, who knows.
At the end of the day its practical experience/knowledge that counts - I bow to your superior grasp of both.

Regards

Sean

lockiedog
Pagoda
Posts: 139
Joined: Mon 29 Dec, 2008 6:49 pm
Model you own: w123
Location: Samford Brisbane

Re: 300D Timing Chain Replacement

Post by lockiedog » Sat 28 Mar, 2009 11:34 am

Hi

I am about to do my timing chain and I am just asking what tool do you use to press the new clip on with, can you use any standard timing chain tool the fits the chain.

And also how hard is it to replace all the slides and rails?. Do you need the pullers to get them off like the say in the manual. ( because i just did a timing belt in a hilux and in the manual it said you need a puller but I got them off without)

And do you know any good mercedes benz machanics in brisbane that would do the job. (And a rough prices).

Thanks Alot

Alex
1984 300D 378409 Auto Manila beige
1979 240D 474789 Manual Light ivory

mathuisella
Finnie
Posts: 298
Joined: Sun 08 Jun, 2014 7:03 am
Model you own: w123
Location: Brisbane, North side.

Re: 300D Timing Chain Replacement

Post by mathuisella » Tue 14 Nov, 2017 11:12 pm

Thinking about doing the timing chain myself after i take a look at it tomorrow morning. How did you go with it Lockie ?

User avatar
Tony From West Oz
OZBENZ moderator
Posts: 3055
Joined: Mon 20 Jun, 2005 10:04 pm
Model you own: w202
Location: Bedfordale WA

Re: 300D Timing Chain Replacement

Post by Tony From West Oz » Wed 15 Nov, 2017 12:27 am

IIRC, the chain guides can be removed by screwing a suitable thread (bolt) into the retaining pins and removing the pins (interference fit) and the guides can then be removed.
I used 3 hammers to peen over the link pin ends to secure the 'link side plate' in place when I replaced the timing chain on my OM617 952 engine.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

Post Reply

Return to “W123”