Replacing a timing chain in '93 300D (OM602). The kit did not include a temporary master link for the feed through portion of the show, and I was afraid to use the master link unpeened, lest it fall off in the nether regions of the engine. So we fed heavy hanger wire through the holes, bent it up over the chain and hammered it down as flat as we could.

We got most of the new chain fed through, and with about one foot left to go, the chain bound up and would not continue. We put a lot of torque on the crankshaft but it would not budge. Back and forth several times, no help. Tried gingerly spinning the starter to free it, no help.

Soooooo...we tried to back the new chain out and start over - but it bound up going out too. There is about 4" of play between the two bind points. The chain is stuck and so are we. I am assuming there is insufficient clearance for our temporary pins through a guide somewhere that we can't see.

Anybody been-there-done-that? Any guidance would be appreciated - if not we are scr*w*d

Has tensioner been removed? Maybe moving the rail will help.

I haven't been there or done that. But you are in a difficult spot no doubt. I always think a good place to start is to get an assembly view of the problem. So I chased this down on your vehicle from the "Russian site" It is a decent drawing of the timing and perhaps will give a help. Check it out. Scroll down on the page to pick up the detail parts drawing.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=140134&M=603.971&GA=722.367&CT=M&cat=503&SID=05&SGR=015&SGN=01

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

Whoa ! Un-Happy Times.Sorry for your difficulty

Looking at and Measuring Mine (both)
I'll do the "California Psychic Prognostication".

"Your homemade TC attachment device initially "Bound" on the Bottom Lip of the Guide Rail that is used by the Tensioner to keep "Slack" out of the TC system.Your further efforts (WITH the STARTER) may have "Deformed" the
"Hanger Wire" sufficient enough to Prevent the "Connection" from passing
back over the Dual Crankshaft Sprockets."

EDIT:
On JunKYarDJIM's RU diagram...#50's bottom edge is where the "Crystal Ball"
says your initial "Bind Up" occurred.
(Of course it may have "Grabbed" some part of the Dual Crankshaft Sprockets)

Hopefully, One of the Professional Techs that visit Tomorrow Morning will
have an answer to your problem.(They may have previous experience
"Correcting" the same sort of difficulty, imposed upon them by another owner.)

However, Your assigned reading material for this evening are FSM procedures
for R+R the Timing Cover.

__________________
'84 300SD sold
124.128

A foot to go suggests it's binding in the transition from the crank sprocket to the tensioner guide. Thankfully gsxr has this picture from a 603 which should be identical to a 602 for this situation -



If I had to guess, though, I'd say it's binding between the IP sprocket and lower guide or lower guide and crank sprocket. If you're really stuck, pull the vacuum pump and basket. It might give you a clue as to what's going on or at least a new leverage point to tease through/back the chain.

Might also be binding by oil pump chain where chain width clearance is tightest.

Sixto
87 300D

Thanks to all who chipped in with advice and suggestions. I cannot tell you how much I have learned from these boards since I found this site last year.

After reading all the input and studying the diagrams, we replaced the tensioner spring, thinking that if it was binding up between the tensioner and the crankshaft gear, this would pivot the base of the tensioner and provide more clearance. This operation was successful, and we were able to thread the chain almost to the top.

Almost home....We have hit another binding point and we are stumped. We can see the temporary pins coming up along the tensioner, and they are moving freely.

What else could be binding up??? we have about 4" of chain left to feed.

Tensioner is out.

Maybe you have some bunched-up chain in there... if you are sure you can keep your temporary pins free, maybe you should back it out pretty far before going forward again. Another possibility... with all the difficulty you've had so far, is it possible your cam got out of time and a valve is hitting a piston?

__________________
1987 W201 190D

Remove the lifters to close the valves, if you think they are touching piston.

The second binding was the valves hitting the piston head. Turns out the rockers on the used motor I had just installed were about 175* out of alignment. So much for "it was running great before I pulled it from the car."

Caveat emptor.

I don't understand this about the rockers being out of alignment... I fear we haven't heard the end of the troubles yet.

__________________
1987 W201 190D

JonL your words were prophetic.

So we finally got the timing chain reassembled, crank at 0*, camshaft marks lined up, buttoned it all up.

It starts with difficulty, runs very rough, lots of smoke, will die if I take my foot off the accelerator. Not the look we're going for. Threw in the towel at 2000 hours last night.

Bit of background: '92 300D with 415K, bent a rod. Found a OM602 from a '93 at a local junkyard (that in and of itself is amazing for Maine). Understanding the risk, I bought it because (1) head looked brand new & (2) the IP was intact and apparently untouched. JY man assured me the car was running well before he pulled the motor and disposed of the car. We had hoped to get this cab on the road in about a week. LOL

Swapped out bolt-ons, fuel injectors, glow plugs, new filters, now new timing chain. Now I'm thinking IP timing. Is there a DIY out there on adjusting IP timing on a 602?

Look under resources, articles, at top of page. "Removal of 603 injection pump" reviews timing. What part are you calling a rocker?

By rockers, I was referring to the camshaft lobes

If the valves did hit the piston head, there is the possibility that the valve stems or heads are either bent, or damaged, and are not closing correctly, which may account for the poor running you are experiencing. Good luck

__________________
96 E300d

Compression test.

__________________

Gone to the dark side

- Jeff