I've tried searching this site for information on how to replace the timing chain guides but can't seem to find the right information. Is there a step by step guide somewhere or can someone explain the whole procedure? I've read about them breaking and causing major problems so I'd like to address this before it's an expensive proposition.

Thanks,
Geno.

Replacing the top 3 guides are do-able but replacing all of them is a *****. The lower ones require the timing chain cover to come off and many other parts that go along with it. The top three are often the ones that cause the most damage when they break. I doubt that you would find a step by step procedure or someone to be kind enough to write it up for you because it's not simple. There are a bunch of other stuffs should also be replaced while you are at it.. so the list grows instead of just the guides...

Try alldata.com. They have decent info but do cost $25/yr subscription.

Good luck.

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1991 420SEL Project Car (Completed and rides beautifully) http://www.peachparts.com/shopforum/tech-help/112321-free-1991-420sel.html
2000 BMW 740IL
2000 Integra Type R - Track Car - SOLD
2005 S2000 - Track Car
06 C230 Sport
89 560SL

do a search on thomspin. by far the best in the business. he has a website too and for something like 30 bucks you can have all the info with pictures you need.

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Thanks Much!
Craig

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Im halfway done with replacing the 3 top guides on my 560SL. I will try to get you some pictures. But basically the procedure is as follows

1) Disconnect battery

2) Remove plug wires from spark plugs and place clear of valve covers

3) Disconnect the fuel cooling lines from the AC hose (If you have this)

4) Disconnect the power brake vacume line.

5) Disconnect vacume lines that cross over the right valve cover.

6) Remove both valve covers

7) Rotate engine to TDC #1 cyl (verfy camshaft timing marks are aligned)

8) Remove distributor

9) Remove power stearing pump leaving hoses connected and set pump aside

10) Remove alternator leaving electrical connected and set asside

11) Tiewrap chain to camshaft sprocket and remove left camshaft sproket.

12) Using a MB special tool slide hammer (prefered method), remove 2 pins for each slide as follows:

a) Make a mental not of each pin depth.

b) Remove upper pin first and reinsert into position 3/4 way to support the guide rail when you remove the lower pin.

c) Remove lower pin fully

d) Grab slide firmly with one hand and pull out upper pin with other hand.

e) Carfully remove slide. Do not drop it

13) Reinstall new guides and seat pins into place using a short 6mm socket head cap screw, screwed full into pin and a soft hammer to drive in to the depth you previosly observed. You should be able to feel when it's home. Remove 6mm cap screw.

14) Reverse the assembly proceedure. Use locktight on camgear sproket

Note the special MB tool can be made up with any slide hammer weight and a 6 mm threaded rod and washers. Just be carefull of what you might poke the threaded rod into when your pin drives free.

An alternative meathod is to use a 6mm bolt to draw against a 1/4" drive 1/2" socket or washers large enough to allow the pin to clear. For really tight places use a 1/4" drive 10mm socket. The amount of thread engadement is controlled by stacking washers under the head of the bolt to make up for the length of the bolt. This sometimes becomes difficult because some pins are on a radiused area. This can be addressed by placing a standard open end crows foot adapter under the socket butted up to the radiused area and allowing the socket to stradle the crowsfoot face. The last time I did this I only had a flare crows foot but it still worked. Be patient using this meathod because you have to balance the act of how many threads are engaged into the pin and how many times you plan on changing washers. For the first time use a minimum amount of washers so more threades are engaded and you only pull the pin out a slight bit befor the bolt threads bottom in the pin. After you crack the pin you can get a little more aggresive by adding more washers and starting with less thread engadement.

For the left cylinder head the inside upper pin is to close to any radius to use any combination of washers, crowsfoot or sockets. For this pin you can use the camshaft washer to make a bridge between the valve cover gasket mating web and the boss for the power steering pump mount. since the boss is lower than the VC web you will have to shim the washer with another washer or shim stock on the boss. I enclosed a picture of this.

This sounds complex so I will try to get you pictures in the next few days. If you cant wait that long just e-mail me with any questions.

Good Luck
John Roncallo

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Attached is a photo of the use of a crows foot to get at tight places. Actually in this position I may have prefered a 10mm socket but I used the crowsfoot for illustration.

John Roncallo

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Attached is a picture of the use of a 10mm socket on the upper outboard pin of the left cylinder head. This is probably the best way to do the lower outboard pin as well. For the inner lower pin I recomend using a 1/2" socket since there is plenty of room.

John Roncallo

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I stand corrected. THERE IS someone kind enough to do the write up..

I love this web site..

__________________
1991 420SEL Project Car (Completed and rides beautifully) http://www.peachparts.com/shopforum/showthread.php?t=112321
2000 BMW 740IL
2000 Integra Type R - Track Car - SOLD
2005 S2000 - Track Car
06 C230 Sport
89 560SL

Replacing the upper timing chain rails will require that you have the proper pin puller. A source for this tool is Performance Products4benz.com.
The next step is to place the engine on top dead center and aligh the timing marks on the cams and crankshaft pulley. Disconnect the battery . Next remove the power steering pump complete with mounting bracket and the alternator complete with mounting bracket. Using plastic ties affix the timing chain to the timing gears. Back off on the big cap nut on the timing chain tensioner but do not screw it all the way off.Stuff a rag into the cavities of each cylinder head to make sure that you do not drop anything into the engine. Remove the two timing gears off of the cams being careful of the washer on each cam. Next thread the pin puller into the chain guide pin and pull the pins out freeing the old rails. Change one rail at a time to make sure that you don't mix them.The pin puller threads are locater under the alternator and p/s mounts on the front faces of the cylinder heads. After the new rails are installed replace the timing gears back onto the cams starting on the drivers side so that all slack is pulled out of the chain on the driver's cam from the crank gear.Ditto from the left gear to the right gear.The gears should slide onto the camshaft keys without moving the cams. Check timing marks and rotate engine with socket wrench and recheck timing marks. If the chain is too tight to get on compress the right side tensioner rail with a large screwdriver.

Purchasing the FSM would be a good start, I wouldn't consider doing major internal engine work without one.

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