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Mission accomplished!

2K views 10 replies 8 participants last post by  MADMAX560SEC 
#1 ·
First time changing the timing chain. It's really not hard at all. Anyone thinking of changing it 'soon' best DO IT NOW! My car has 157k on the clock with 5degree stretch.
I can't imagine another job this easy for as technical as it sounds. If you DIY, just take it slowly and take advise from this forum. If you recall that post from someone here titled "buy a lottery ticket" my case was similiar. Driver side top rail was broken in half and was grinding between the idle pullys. Tensioner rail is grind down to the minimal, while the pass. top rail snaped during the rolling process of the new chain. Lastly, the only problematic encounter I had was the damn top pin on the driver side. My 'puller bolt' broken off inside the pin and this trial and error process to drill, tap, grind, and cut took an additional 3 days!!! All and all, this was a smooth sailing job.

Parts replaced:

New Chain
New Tensioner
3 top sliding rails (2x172mm and 1x142mm)
1 tensioner guide rail (don't buy the whole piece with the metal and all, you can find just the top plastic replacement for a fraction of the cost. $7 vs. $40)
2 sets of oil line clips.(dealer item)
2 valve cover gaskets.

That's about it, cost: ~$200 from Mr-auto-parts.com

Well worth the time and experience. I will consider changing timing chain for any other car I purchase in the future as a post purchase maintainence to give a fresh start.

Thanks for this forum, in the meantime, I have to sort out the shaky idle and hot start issues.

Cheers,
Brian
 
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#3 ·
Would you post step by step on how to do the job? I am an DIY, and would like to have the process for when I need to do it. My 300SE only has 48K at the moment.
 
#4 ·
Having looked at the engine exploded diagram, I don't see any problem replacing the upper guides, but I've wondered how much you have to tear down to get to the tensioner. Is it accessible by just removing the valve covers, or do you have to pull the front cover - remove the water pump, etc.

Glenn in Tucson
84 380SE
 
#5 ·
Tensioner comes out the side - two bolts. Tensioner guide is another story. Getting it into the engine isn't too hard but that lower pin is a bitch.

The hardest part of the whole replacement process for me was the three pin sets that hold in the stationary plastic guides. I didn't have a slide hammer.

Well worth it though.
 
#6 ·
The tensioner rail is retained by a hollow pin, about an inch long and 3/4 in diameter. It is covered by an allen wrench cap just behind a water hose. Very easy to get to and you'll need a pick/hook and a needle nose pilers to wriggle it out. The side tensioner is retained by two 13mm bolts, very self explainatory. (i used a Chanel makeup mirror to discover this pin, shh... don't tell my gf.)

Yes, you'll need to remove the alternator and bracket, as well as the p/s pump and bracket, and distributor/ignition unit to get to those 6mm internal threaded pins, which hold the 3 sliding rails. Lower rails will be another story and I'm not ready to face that reality.

I can't give a detailed step by step, but here's an idea...

1. remove valve covers and misc. 'things in the way.'
2. fan/clutch and radiator shroud. Then get a piece of cardboard to protect the radiator during your work.
3. loosen and swing away alternator and p/s pump along with their brackets.
4. remove spark distributor, advance unit, and spark plugs.

...after the preliminaries:
5. remove chain tensioner.
6. grind off a link on old chain, clip new on with masterlink. I used the box as a dispenser, very helpful.
7. roll new chain in clockwise with a 27mm socket and proper extension at the crank.
8. continue slow and carefully clamping the open end chains with vise grips.
9. pull out tensioner pin, sliding rails pins and replace each one accordingly. For the sliding rails pins I used a 6mm bolt, a 3/8 drive socket 13mm and a number of washers and nuts. Pull these pins out gradually because u don't want to have my same nightmare caused by breaking the 6mm bolt.
10. Note the tensioner guide rail and driver side 142mm rail requires the removal of the cam sprocket to extract; unless there is another way, but at that given time I figured it was the easiest solution.
11. replace oil line clippings.

Then the rest are in the reverse order. Tap in the pins, torque the bolts, make sure the timing marks are lined up... and so on.

Some suggest replacing all the rails before rolling in the new chain to use the slack of the old chain as an advantage, which make sense.

Reinstall all the accesories drives and belts, then u shouldn't have any screw/bolt left over.

Look into the DIY thread of this forum for illustrations of this job. That should be it, but I might have left out some obvious steps...[:)]

GOOD LUCK!
Brian
 
#7 ·
absolutely amazing!
i wish you lived near me and i would ask you to do this job! :)

good luck with your car on more fixes..

DinoMobile - 3/2/2006 3:53 PM

First time changing the timing chain. It's really not hard at all. Anyone thinking of changing it 'soon' best DO IT NOW! My car has 157k on the clock with 5degree stretch.
I can't imagine another job this easy for as technical as it sounds. If you DIY, just take it slowly and take advise from this forum. If you recall that post from someone here titled "buy a lottery ticket" my case was similiar. Driver side top rail was broken in half and was grinding between the idle pullys. Tensioner rail is grind down to the minimal, while the pass. top rail snaped during the rolling process of the new chain. Lastly, the only problematic encounter I had was the damn top pin on the driver side. My 'puller bolt' broken off inside the pin and this trial and error process to drill, tap, grind, and cut took an additional 3 days!!! All and all, this was a smooth sailing job.

Parts replaced:

New Chain
New Tensioner
3 top sliding rails (2x172mm and 1x142mm)
1 tensioner guide rail (don't buy the whole piece with the metal and all, you can find just the top plastic replacement for a fraction of the cost. $7 vs. $40)
2 sets of oil line clips.(dealer item)
2 valve cover gaskets.

That's about it, cost: ~$200 from Mr-auto-parts.com

Well worth the time and experience. I will consider changing timing chain for any other car I purchase in the future as a post purchase maintainence to give a fresh start.

Thanks for this forum, in the meantime, I have to sort out the shaky idle and hot start issues.

Cheers,
Brian
 
#8 ·
I am still in the process of chaning my chain, the upper guides are now replaced, I also had a heck of time getting the last couple pins out of the head, I tried a homemade slide and 6mm bolt to no avail, so it sat in the garage waiting for a guide puller, WOW wish I would have bought one before I started the job. I still have removed the chain tensioner to give me some slack on getting the sprocket back on the cam, having a time with that, noticed my timing marks have a moved a bit, so need to re align and try again. So far its more just take your time, and dont drop anything down the engine.

Shouldnt be any problem putting the bolt back in the cam shaft and rotating a revolution to get my marks lined back up should there?
 
#9 ·
Congrats!

I just had my timing chain replaced. Today makes one week ago that I picked my car up from the mechanic's shop.

It was worth the wait! I have enjoyed driving this car more and am looking forward to more repair and replacement work....

Way to go, your info helped me alot as well!


[;)]
 
#10 ·
MADMAX560SEC - 3/3/2006 2:59 PM

I am still in the process of chaning my chain, the upper guides are now replaced, I also had a heck of time getting the last couple pins out of the head, I tried a homemade slide and 6mm bolt to no avail, so it sat in the garage waiting for a guide puller, WOW wish I would have bought one before I started the job. I still have removed the chain tensioner to give me some slack on getting the sprocket back on the cam, having a time with that, noticed my timing marks have a moved a bit, so need to re align and try again. So far its more just take your time, and dont drop anything down the engine.

Shouldnt be any problem putting the bolt back in the cam shaft and rotating a revolution to get my marks lined back up should there?
You definitely need to loosen or take out the tensioner before there's enough room to get sprocket back on cam. Try turning crank left and right no more than a few degrees to play with the chain slack. You shouldn't rotate the cam shaft more than a few degrees to align the marks.
A revolution is a big NO NO, unless you have the rocker arms removed. Make sure you didn't bent any valves already if your timing marks are that much OFF!

Good luck.
Brian
 
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