timing chain replacement questions
 

Hi All,
First off does ANYONE have a good timing chain crimp tool that I can rent?
Haven't had any luck in the tool rental section here. Read in some posts by member Rogviler
that he tried using a cheap ebay crimper for the OM617 chain and it definitely did not work.
So I'm looking for a good brand name tool and don't want to spend $300 for something I'll use once.

Right now I have 6 degrees of stretch and ten years ago I put in an offset
woodruff key when I had the head off so I figure it's past time for a new chain.

I did not keep the original key which I assume had zero degrees of offset?
Anyway I don't see a plain woodruff key to buy listed and I assume I need that for new chain install.
Does anyone have a source for that plain woodruff key?

Was going to use the dieselgiant tutorial for this job. How to Replace Your Timing Chain
Any advice or words of wisdom would be greatly appreciated!


Thanks,
Jeff

You already know this but...change it before it breaks. I've seen a few 616's break and the aftermath isn't going to just buff out.

Pull the valve cover and inspect the gears for any that have worn in a shark tooth fashion, they need to be replaced. Replace every guide rail you can, ones that are beer bottle brown are ready to fail.

Clearly mark TDC on the balancer and the pointer from the start so they are easy to read later.

Zip tie the chain to the cam gear and stuff the cavity with clean rags before splitting the old chain.

Don't let the chain drop, don't let the chain drop, don't let the chain drop...

Enlist the help of a FOCUSED assistant to help roll the new chain into place and eliminate all distractions e.g., cell phones.

This isn't a difficult task if everything goes as it should, but something like dropping the chain can be the start of a bad day.

Roll the engine over a few times by hand before starting it up.

Adjust the pump drip timing after the chain has broken in a few hundred miles.

Adjust the valves if not done recently.

Look around town for any older foreign car shops, they may want to sell the crimp tool at a fair price as they never use it anymore. Ask a tool truck sales person for steerage to such a shop.

Sugar Bear,
Thanks for all the good points. The car is going to be parked until I roll in the new chain.
My son and his friend will help. Both good responsible young men.
Measured the chain using 2mm lift method after adjusting the valves.
Will take my time and do it right. That's why I want the correct tool.
If I was in my 20's might be tempted to go the ball peen hammer route.
Me old and wise now:D Next time I see a tool truck will stop and ask
Jeff

Good to mention the timing gears. Nearly everyone forgets about them.

Pulled the camshaft gear and found that I had not put in an offset woodruff key before.
So, I am only at 6 degrees stretch and the FSM allows for 10 degrees.
The gears look good from what I can see.

I have decided I am just going to put in a 3 degree woodruff key and not mess with
rolling in a new chain, finding the right crimp tool and changing out gears.

Also, it's confusing to order the right key.
Camshaft woodruff key degree is 1/2 of the reading at the crank.
You can get them in 2,3,4 or 5 degrees.
Attached is a pic I took from my 617 FSM which includes the part numbers.

Jeff

That is good news. I'd still do a drip timing on the pump. When a 617 is dialed in they run well. Also consider measuring boost pressure, a lot of power might be being left on the table.


The chain guide on the upper left is easy to change while you are in there, it is worth a look.

Thanks SB. Years ago set the IP timing at 14 using an A-B light I had rented.
Also have installed a boost gauge with controller at wastegate set at 13 psi.
Installed new SWAG tensioner and those top two chain guides when we had
the head rebuilt 12 years ago. They seem good.

Car's been running well but smoking on acceleration. Nearly all my valves were tight when
I did the adjustment this time, so I was behind on that. Also, recently had Greazzer rebuild my injectors, he's the best.


Jeff

Sounds like a well cared for and dialed in engine. What color is the smoke?

Smoke is light gray and not heavy. Happens when I start after sitting at a stoplight or
accelerating on Hwy. Will see if it improves after this last valve adjustment
and correcting the timing with the woodruff key. Years ago I removed the
Alda and that is probably the main culprit. Also have fully rebuilt the turbo
so it's not that. Hey, it's an old car.........but the engine is smooth and sounds great.

Jeff

For anyone following this who wants to rent the Baum chain crimp tool. I found it for rent for $25 plus shipping.
You get to keep it for 30 days. It's listed at BenzForce ​chain crimp tool​​​

Thanks for sharing the info.

Car all put back together and running well after putting in the woodruff offset key.
It's now showing 1 degree at the crank. In all the threads I read no one actually says
which way to insert the key. So, for anyone who isn't sure, with the slot at 12:00 you
want the key to be leaning towards the passenger side of the car to correct for chain stretch

Any noticable difference in how it runs, starts or sounds?

There’s no need for the crimping tool. Two average sized ball peen hammers is all you need. Get the pin link in place from the rear and then feel of the holed link to find the smooth side. One side will have sharp edges and the other side will feel smooth with no sharp edges. Put the holed link in place with the smooth side forward, away from the chain. Use the flat side of one hammer to back up on the back, and use the ball side of the other hammer to peen the pin leaving a bit of a mushroom shape.

Peening against the smooth side leaves a radiused head on the pin which is much more resistant to cracking.

I’ve done more than a half dozen chains this way and driven some to high mileage without issue.

Hope this helps.

SB--no big difference so far that I can tell. Car was driving pretty good before I did this.
I think it might be smoking a little less. Need to have my wife follow me to check.
When I was finishing up realized I had cracked the little radiator fitting that goes to the expansion tank.
Glad I caught that before driving it! Fixed it using the tire valve stem trick others have used.
Been for a few short drives and it is holding up well.

Air & Road, thanks for the info on using ball peen hammers. Someone over on
Benzworld also says that is a perfectly legit way to go.

Appreciate everyone's input on this little project.

Jeff