Glow plug removal-What are the best tools??
 

I have 2 Mercedes, '81 and '82's. I have fought the tight spaces, and realize there must be a better way than what I'm using, which is basic ratchets and open ends. Are there specific sizes or combinations of, say, long handled wrenches, pivot head wrenches or even flexible drill motor type set-ups that would allow me to get to these little boogers in a less miserable way than I'm using now? Any special tools that you all have purchased that I could buy? (Where-how much?) I'll throw in the same question for valve adjustments, too. Thanks for any suggestions! Lee

I just did some glow plug work yesterday and did not feel frustrated.

I have learned to take off the injection lines for easier access.
I just take the 17mm connectors off at the pump and the injectors.

Even if you do not take off the lines, the GP's are 8mm nuts for the wire
and 12mm for the plug itself.

I use 1/4 inch drive tools with extension and a wobble type end or a universal.
Using this I can get in and loosen the nut then the plug.
The 12mm I use for the plug is deep socket.

I still wiggle my hands in to take out and insert the plug and nut.
Much harder to do if you have large hands.

When I tried open end or box end it was more difficult for me.
So now it is sockets.

I leave the hard lines on, and use gear wrenches. On #5, I move that hose out of the way, and disconnect the throttle linkage thing to gain access.

A 12mm ratchet wrench would be helpful for the GPs. Order a GP reamer from Diesel911 in the For sale section of this forum. Great tool!

John

to get them out easier let the engine get hot or you could have trouble getting them out. if you dont let the engine heat up then use some PB blaster, if you dont use any of these steps you run the risk of the glowplug breaking of in the head, just some extra insurance.

PB Blaster every few days for about 2 weeks before I did them.And GEAR WRENCHES.

I assume by the years of the cars, they are either 240Ds or 300Ds, or 300SDs or a combination of those. Those would all be 616 or 617 engines. On those I use a "gear wrench" as noted already - on of those Sears Craftsman 12 mm combination wrenches with a ratcheting feature on the closed end. I have never had a glow plug on one of those beasts break off in the head, and am not sure I have even heard of that happening. The later, aluminum head Diesels, especially the 606 series seem particularly susceptible, but they are mid and late 1990's machines.

The cited tool takes most of the access issues and makes them moot. The last cylinder on a 5 cylinder (next to the firewall) may be difficult even with this wrench - I have never done this on a 5 cylinder so I don't know.

Good luck, lots of ways to get this job done and none are really difficult. Jim

I did mine in 2 hours without removing anything other than the throttle rod -one that comes thru the firewall and a vac line or two. Figured the less I disturbed the better. That 2 hours also contained a cig break or two as well.. And #5 wasn't that bad. JimmyL lent me his reamer. :D

Gear wrenches. I can change them out in 20 minutes without removing anything but the plugs. Never had a problem with #5. Put rags down between the block and IP and block/oil filter housing to catch any falling nuts/plugs/wrenches.

Wow
 

How many time did you have to do it, to get it down to 20 minutes? I'm impressed.

Thanks, but...
 

Hey, thanks alot everybody! Yep, I forgot to mention that the 81 is a 300D and the 82 is a 240D. I changed the 2nd from the front and the rear on the 240 the other day (My daughters 4 cylinder), which were leftovers from the two that I didn't put in the wife's 5 cylinder, due to frustration and mostly cramped wrists and fingers. As in my 6.2 Suburban, I've found that they're probably a lot tougher due to the fact that some previous owner didn't want to do it at all. They're always easier the second time, before they've had time to antiquate and "become one" with the engine. The 240's seem to have less room to move my hands under the curved injector tubes. I was working with 1/4 and 3/8" ratchets and small open end wrenches. Seems the wobble joints were just a tad too long. Thought maybe a long handled ratcheting closed end might be the ticket. Now for my question out of ignorance-(this always seems to hurt more when I thought I knew it all already :o. What exactly is a 'gear wrench'? Is it the open end/ratcheting closed end that I have been using? I've got a set, but they A) are standards, and B) sure seem like they could be longer for the sake of ease in the very short cranking radius that I'm working with. I do have, as I said, sets of 1/4 and 3/8 metrics. Anybody have any suggestions on other stuff, such as swivel head open/closed ends, or nifty specialty tools that I also don't know anything about? It seems I see a lot of posts mentioning "get the 'tools' ". Anyway, thanks for the suggestions, and you can bet I'll be asking a lot more questions. And I'm waiting for the gear wrench answer.

Don't forget to put some type of Never-seez compound on the threads of the new plugs so that they are easier to remove the next time.
When I remove my glow plugs I always remove the fuel injection lines (with a 17mm crowfoot and a flare nut wrench). For me this is faster in the long run. If I did not do it this way I would need to have a small bag of those 8mm nuts before I start the job. Even with the fuel injection lines off I have managed to loose 2 nuts in one year.

Ive done it in the same fashion with good luck. The stubby gear wrench was the key.

I remove the hard lines. Doing it the other way is tough if you have large hands. I can do it maybe in twenty minutes, or, not much more.

Tom W