Hi folks,I've been looking around for any sort of DIY article that sums up the essentials when replacing the timing chain on a 617 eng. I have been addressing some deferred maintenance issues on a '78 300cd I picked up earlier this year with 270k mostly documented miles, and figured I may as well replace what I believe is the original the timing chain (have not checked stretch). I've replaced several timing belts on Audi's that I've owned in the past but never a timing chain, so I have a few questions:

1. Aside from the MB tool for crimping the new link (and a dremel for grinding off the old link), is there anything else you recommend I should have before attempting this procedure (not considering the typical tools all DIYs have, which I obviously do)?
2. Is there any recommended procedure for rolling in the new chain? For example, would you suggest using the vice grip method, which is slow/arduous but probably more exact, or suggest doing it with a helper to 'guide' the old chain out and new one in while turning the engine?
3. Most importantly - is this one of those procedures better left to the pros?

Thanks!
Note, chain & tensioner will be sourced from Phil.

http://dieselgiant.com/replacetimingchain.htm

If the job requires removing chain guide pins, the dedicated tool works much better than stacking washers or fashioning a slide hammer.



Sixto
87 300D

Thanks Sixto - is there a tell tale sign for condition of guide rails? I was hoping to simply roll in a new chain & put in a new tensioner since it idles/runs smooth enough.

If it turns out new rails are required then I think I'll let my Indy do this, since I don't have the aptitude to tackle this.

There's a guide rail visible just to the port side of the sprocket. Check how deep the channels are in the plastic material. Consider that the contact surface is flat when new. You might be able to see the contact surface of the tensioner guide while the chain is out of the way. The upper guide is easy to replace. It's held by one bolt and one pin. What a worn upper guide tells you about the other guides is a matter to discuss with your mechanic.

With the crank and cam back in time, you should probably check IP timing to complete the hat trick.

Sixto
87 300D

Makes sense...thanks Sixto. I appreciate the useful info and different angles you've brought up which I wouldn't have thought of otherwise.

Looks like I'll play it safe and take the new chain/tensioner to my Indy and let him handle the rest, since there are several variables to this which I'd rather not mess with.

Thanks again!

After you have spent good money on an IWIS Timing Chain skimping on the Timing Chain Tensioner Rail is not a good idea because the Old Chain has worn a groove in the Rail. You do not want the new Chain to be pulled into the old Groove.
Only the large Rail needs to be replaced. To the best of my knowlege there is no constant contact with the other Timing Chain Rails. They onlyl act at guides.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

Thanks for the input Diesel 911.

Does the R/R of the timing chain tension rail require removal of the timing cover?

I don't think a 617 has a removable front cover.

Sixto
87 300D

There is no timing cover on a 617.
You have to remove the crank shaft belt pulleys and the vibration damper.
Do not loosen the 27mm bolt, just the 6 Allan bolts around it.
Ones removed rotate the crank until one of the cutouts of the crank disk line up with the pin that holds the sliding chain rail.
The thread in this pin is M 8 X 1.25.

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76 240 D. Bought in 1998 for $25.
85 300D. Got it for free with a bad engine. ( Sold )
60 Unimog 404. What was left of it, was given to me. Now powerd by 617A.
88 560 SEL. Bought without engine and trans. Now powerd by 617A.
67 250 SE. Cuope. For resto or sale.
64 220SE. For resto.

Here is a good thread CELL did awhile back replacing the Timing Chain etc...

9 degrees of chain stretch

Charlie

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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

Thank again everyone for the useful input!

Sixto & mog - much thanks for the diplomacy regarding what I realized was a really dumb question (the lack of a 617 timing cover)...I was thinking of my 300sdl for some odd reason. Must be getting senile here...

I'll have to think through the logistics carefully before proceeding. If I end up doing it at home I'll go ahead and post pics.
Have a good evening.

Just read through CELL's post...he did a great job. Excellent attention to detail. Thanks for reposting this Charmalu.

Well, this is really frustrating since I had the pulley & damper off a few weeks ago along with everything else on the front, to change the WP housing seal (to block) which had sprung a leak. Had I thought this through back then, I could've got into the tensioner rail while everything was out.

For now I'll replace the leaky oil cooler lines first and probably drive it sparingly for a few months (this is really my wifes weekend car) before coming back to the timing chain & rails. Probably won't be until spring or so, but now that I know what I need I can start planning ahead.

Thanks again folks for all the great help!