hey guys

another t-chain q

think i found a decent mechanic near me - in bus. many yrs

took the car in for oil change and break pad check

wanted to check out the shop / seems aok

first words out of the mechanics mouth aft saying the car is a keeper / its a good time to change the T chain

was told at about 100k its a good time to change the timing chain / rails and quides - the job would be @ $ 700

would also fix anything else as needed

heres the thing / i was concerned about the timing chain simply from what i have read here, and was looking for a shop to do the job anyway- in case of.

think i found one

NOW

i have owned the car for a few mos. / doesn t seem to need anything / winter is setting in / i don t plan on driving the car in foul weather / now would be the right time for such a job /
the money isn t the issue - was prepared for this when i bought the car / creating problems is the concern

i don t want to start problems by changing the T chain etc. and opening the belly of the beast, so to speak


one other thing - where do you get the degree stretch no. from?
how does one find out the chain has stretched?

would like input from from the more experienced, please

thanks in advance
jim

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As an '84, you probably have a dual-row chain. If so, it is pretty simple to pull the right valve cover and observe the chain stretch and wear on the tensioner rail, and bring #1 to TDC and look at the cam marks. At least then you can make an informed decision. If you have only a small amount of stretch, why change?

If by some chance you have the single chain, you need to upgrade to the dual setup - major bucks.

__________________
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

The chains do stretch on these M116 and M117 engines over time, because the chains are long and change direction many times as they travel from the crank at the bottom up to each cam on each side of the "V".

Most members and techs on this site recommend replacing the chains approximately every 100,000 - 120,000 miles. 4 degrees of stretch is considered the time to change the chain.

Further, it's more than just a loose chain that's the problem. The chain guide rails are made of plastic, and become hard and brittle over time, as well. As the chain stretches, it becomes loose, and starts to rattle and bang and slap against the guides. It usually happens at start-up, but when the chain gets loose enough and the guide rails are old and brittle enough, the chain will slap against the plastic and it'll break apart. Plastic pieces will get stuck in the chain and the sprocket, and bam!, you've bent a camshaft, pistons will hit valves, etc.

I've found from reading posts on this site, that's it's more often a loose chain breaking old guide rails, than a loose chain jumping a sprocket that causes an engine failure.

Your car may or may not be due for a timing chain replacement. But at minimum you should replace the upper guide rails.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

And if you car is equipped with the single row chain, and you don't want to upgrade to double, expect to replace the chain every 30K miles.

Timing chain replacements are easy and really don't involve "opening the belly of the beast". An ounce of prevention is worth a pund of cure.

__________________
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.

Location: new jersey
Posts: 21
84 380 sl timing chain replacement
hello all

i have read all the replies
digested the information
am having the t/chain replaced as i type this ( 99500 mi )

as stated previously / ( 84/380sl timing chaim 99k )

think i found a decent mechanic
left the car mon/the 11 th - will be finished this wk

i would not have know about the t chain if not for this site and the people who visit

thanks for all the information and help
its only through the replies by informed and knowledgeable people, that people like myself (new to the mercedes car) can better understand the mechanics of the mercedes, along with the things to look for when something go wrong.

will let you know if there is any noticeable difference with the new chain.

one other thing

noticed a slit bang when putting into gear from park
asked the mechanic to chech the universal joint
the car hasn t any
didn t know it had the rubber collar akin to the old volvos 122s - p1800 i have had both - loved those - did all the work myself

jim

ps - i included a picture of my car last post - no remarks ?

hey people

had the timing chain changed out of concern

received a call from the mechanic the car is finished

replacement of timing chain

timing chain , replaced upper cylinder head mounted chain guides, tensioner with chain clamping rail, r/s valve cover gasket, plugs, fuel vapor canister, replaced all rocker arms, are new.

along with the removal and cleaning of camshaft oil tubes,

cleaned and flushed cooling sys refilled with mb coolant.

99692 mi


the cam shaft had been changed somtime in the past without changing the rocker arms

the shaft is fine changed the rocker arms due to wear

thanks all, for the advice - i would not have known about the timing chain issue if it weren t for this site and the people who visit

jim

Excellent. Now you can have piece of mind on this car for at least the next 100,000 miles.

Nice picture of the car. Looks like it's in great shape. Oh, I have for many years lusted after these W107 chasis 450 SL/380 SL/560 SL's.

Maybe someday...:p

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".