300E Heads R & R What Else?

1989 300E :215K with a bad leak in my head gasket. Typical valve guide problem so I'm pulling the Head Tomorrow with my son . We just got done restoring 351W Ford engine and the 300 E head doesn't look that hard to do. I've researched the forum and found some good advice (#12 star piont socket)
1. Do I need any special tools for this?
2. danger areas to be aware of.
3. Do I replace the timing chain?
4. I have to replace that little shock on the front of the engine
so Do I pull the radiator.
Anything else You can think of?

Machine shop that did my other work will do the valve job on the 300E and reinstalland setup the cam& timing for $350.
I think $500-600 should do it for everything.
thanks..
MV

[Benzmac]

One thing is the hidden pin holding the front timing chain rail to the head. It is threaded with a 6mm thread so you can pull it. If you don't pull the pin out of the head/rail, you will break the rail.

[Gilly]

I work in a dealership, so I guess the neccesary tools are readily at hand. It would seem difficult to me to try to remove the fan without the proper tools. Also the guide rail pin puller as Benzmac already commented on. You also need to be careful when removing the head to not bust the rail itself (the guide rail sticks above the level of the timing cover).
On the belt tightener shock, sometimes you can tell when it really needs to be replaced. If the engine has a loose belt, it's not due to the shock, though. Probably the tightener is worn out. I usually replace the shock if one of the aluminum inserts on the end can be pushed out by hand, but yes, sometimes it's obvious by the noise that the shock is bad.
At this many miles, it may not be a bad idea to replace the timing chain. I guess it depends on what you want to do with the car, as replacing the chain adds quite a bit to the labor bill. If you want to drive it another 200K+ miles, then do it. I would also be looking at new valve guides, make sure this is included in the machine shop estimate.
You wouldn't need to R&R the radiator for this work. If you have problems getting the fan off, you may just end up removing the radiator and condensor to drill out the bolt, so be careful!
Gilly

Do you have a manual. You are right, this is not a particularly difficult job, but there are some tricks that a manual will help you with. Some of them already mentioned, but here goes my list from memory. Maybe it will help.

Use something to lock the fan in place while loosening the allens that hold the fan on. There is a special tool that is nothing more than a bent rod that lays in a slot and lines up with a notch in the back of the fan to keep it from turning. The special tools are a short allen socket and the bent rod tool, but you can probably get by with something if you just know to lock the fan with the slot with some sort of rod.

The guide rail pin. There is a special puller, but a bolt through a socket or something with a washer and threaded into the pin can work as a home made puller.

This engine has a ratcheting tensioner. You will need several allens, I think a 12mm and a 17mm to remove the tensioner. Before reassembling, push the notched plunger all the way through and reinsert. This will relieve the tension and allow it to ratchet itself back in place without damaging anything.

Use some slimy slick sealant on the top timing cover u seal so it will slide rearward into place without disturbing the location of the u seal. Oil the shaft seal and start it carefully with your fingernail to ensure that it does not fold up.

The manual says to remove the intake and injection system with the head, then remove it on the bench. I found it quite easy to leave the injection/intake assembly in place and simply unbolt from the head. You will have to crawl underneath for access to a few of the bolts, but with a fistful of extensions, it's not difficult.

Be careful not to lose the small little metal cups that are at the rocker arm tips at the top of the valve springs.

When tightening down the camshaft stands and rocker arm assemblies, take your time, start all the bolts with your fingers then evenly tighten all of them. You can strip threads or break the camshaft if you're not careful.

Good luck with it,

Brother of The Benz, MikeV
Larry called the shot, get your little grubbies on a Service manual before you make a mistake that will cost plenty bucks.
The small plug that is removed by screwing a bolt into it's threaded ID is straight forward, the kick in your breeches is MAKE SURE THE THREADED END IS FACING OUT WHEN REPLACED. If not it won't be removeable the next time.
Whiether you leave the manifolds on or off the head is your call.
Most important, beg, borrow or steal a manual and save some heart aches.
Hi Larry long time no hear.
Happy Trails beep beep from The Spiderman in Houston!!!

[pmizell]

Benzmac, Gilly, Larry, Donald: is this the 6mm threaded rail pin that you speak of that needs to be extracted with an impact puller? If so I think I'll use Larry's homemade contraption



TIA

~Paul

____________________
'91 300E, 205,000 mi

[cth350]

I built a pin puller from three bits...

- A spare banjo bolt from a transmission cooler.
- A long 6mm bolt that's half an inch longer than the banjo bolt.
- A nut that threads to the banjo bolt.

Drill out the center of the banjo bolt such that the 6mm bolt fits into it. Put the nut on the banjo bolt.

To use it...

- Thread the 6mm nut into the guide rail until everything is snug.
- Hold the nut with a wrench.
- Hold the banjo bolt with a wrench and unscrew it from the bolt. This action will pull the pin too.

To completely pull the pin you may need a spacer nut between the head and the puller after the first try. And you'll also need a longer 6mm bolt.

That puller lasted me for about 6 engines (I bought a lot of dead cars over the years).

One day, I misplaced the banjo nut, so I just used lots of little nuts to get the same effect. A 6mm nut closed to the head of the bolt, followed by an 8mm nut for it to push against, followed by a 10mm nut because it was handy, followed by a 12mm nut since that's the size required to be against the head.

These two pullers only work if the pin can be drawn INTO the nut up against the head.

This year, 2 days before finding the hollow bolt, I broke down and spent the 70$ on the real puller (a carefully crafted piece of metal that is about 4 times longer than my transmission bolt, but just as hollow). Considering that I designed my first one w/o seeing "the real thing", I was very pleased. Except of course, that I was out the money.

-CTH