Timing chain Tool - 117 V8
 

I'm getting ready to swap out my timing chain on a 450SLC. Has anyone used this special tool? It's suppose to firmly hold the chain on the sprocket.

http://i22.ebayimg.com/03/i/00/90/97/9c_1.JPG

Also, would it make a difference if I replaced the top rails first?

Thanks, John T.

I did the chain but did not use such a tool (see the DIY article). I would replace the rails before putting in the new chain, it might be tougher with a new chain (less room to work with, more tension, etc).

Yes, and I like it - it makes the job somewhat idiotproof. Theoretically, one person can do it alone, although my wife fed the chain and pulled the old one out the two times I've done it.

The only bad thing I would say about it is make sure that you torque the bolts to the proper spec and using the proper (oiled) procedures after completing the chain work.

On the rails, I've done things in this order:

0. INDELIBLY mark the gears and chain links on both sides with accurate marks
1. Remove rockers
2. Remove tensioner
3. Remove LH gear
4. Remove and replace LH plastic
5. Replace LH gear (put chain back on)
6. Remove RH gear
7. Remove RH plastic and arm or plastic on arm
8. Replace RH gear
9. Do the chain (cut, splice, pull through, tie new chain back together)
10. Install new tensioner
11. Reinstall rockers


Supposedly, you can remove and replace the LH plastic without removing the gear-but I've found it impossible, and it's just easier to remove the gear.

Needless to say, retorque everything accurately, and avoid turning the cams while removing/reinstalling/retorquing the gear bolts - although this is difficult. I used a big aluminum pipe wrench with steel jaws on the center tabs of the cams while tightening, and a big screwdriver wedged agains the head while loosening.