300sd tmg chain change QUICK question
 

I just replaced my timing chain on a 300SD (83). I put everything back together and thought, "Should have I adjusted the valves (or even checked them) before I put the valve cover back on"?

So, do the valves need to be adjusted after changing the timing chain?

It's hard to say if they need adjusting without measuring them. I'd at least check them.

The process of replacing the chain won't affect the valve lash. It will affect the cam timing........hopefully returning it to spec. It also will affect the injection timing, also causing it to advance.

But, with the valve cover off...........why would you neglect to check and adjust the valves?:confused:

check valve clearances
 

Yes, while you have the valve cover(s) off you should check the valve adjustments. So, it's a judgement call on your part whether to take the cover(s) off and all that entails. If your engine isn't running as it should after putting a new chain on it would be a good idea to go back and check the valve adjustments.

thanks
 

thanks will do....I suppose I should try to adjust the injection pump timing, but HOW THE HECK DO YOU ACTAULLY get to the rear pump mounting bolt?

Ahh, yes, that rear bolt.:(

First you have to find it. This takes at least 20 minutes. But, I'll tell you how to shorten it to about five:

Lay down on top of the engine and peer over the space between the IP and the oil filter housing. Get a very strong light and look all the way down, very close to the spring return spring for the IP. You will see only the head of the bolt.

Time for the first beer and contemplation on how to get to it.

Go out and buy the longest possible 13mm box wrench you can find. It must be at least 10 inches to go from the point just behind the VCV all the way down to the head of the bolt.

Remove the rack dampener bolt on the back of the IP. You won't have enough swing room for the wrench unless you do a custom bend on it. Ask me how I know.:o

Lower away and carefully snag the head of the bolt and move the wrench away from the engine until it hits the oil cooler line. Remove wrench and repeat three times. The bolt is loose enough to allow the IP to rotate.

Tightening the bolt is easier. It's easier to snag the bolt head with the wrench right above the oil cooler line and move it closer to the engine.

The three bolts on the front of the IP are no problem as compared to the rear one. The inboard bolt is best accessed with about 12" of extensions, a 13mm socket, and a universal.

You must find and loosen that rear bolt. I was unsuccessful in reaching the proper IP timing with the bolt engaged.

That's depressing because that inside bolt looks like it'll be horrible difficult to get to. I'm going to replace my chain as soon as its my turn for the crimper on the tool loaning program. I'm going to check my timing while I'm at it. Thanks for the advice about how to get to it, and for mentioning that rear bolt. I had no idea there was one.:rolleyes:

the inside nut between IP and block is easy..you just need a universal joint to put between the socket and the extension....and its advisible to not try for the rear bolt if you are in any way frustrated or having a bad day. Just so you don't end up breaking something as a result.....like window....kicking the dog....or trying to put your fist through a cement block wall or something, ending up in the slammer becasue you took it out on the wife.

Hey,
Replacing the timing chain would have no effect on the valves. Like Brian already stated. You should however check the timing again. Unless you know for sure a woodruff key was never installed.

You need to remove the rack damper bolt to get to that last bolt. It will still be a PITA to get to though.
Replacing the chain should bring the pump in line also. Unbolting it and moving it could do more harm than good. If you really want it checked I would recommend finding someone with an A-B timing light.

Danny

I used this tool for the first time last week. It's a godsend. Best thing ever invented for timing these vehicles. If there is any toy that I want for Christmas.........this would be it.

Maybe I'll buy one and put it in the rental program.