prechamber ball fell off - Page 3 - PeachParts Mercedes-Benz Forum

erubin · #31 02-25-2006, 11:29 PM

Over 20k miles later the car is running strong with the used replacement prechamber replacement. a mechanic said the engine was no good but this turned out to be a relatively low cost repair. Must confess...never did ream out the glow plug holes.

funola · #32 06-30-2007, 11:00 AM

Leathermang, from what you wrote I gather the prechamber has an internal thread that an injector can thread into? Is the thread just for prechamber extraction or is the injector threaded into the prechamber while in the head? I thought the injector threads into the prechamber collar only?

It surely cannot thread into both the collar and the prechamber. Not having seen these parts in the flesh (except the injector) it is difficult to visualize.

Quote:

Originally Posted by leathermang

Replacing the precombustion chamber would normally fix the situation....
and you need to take it out to check in the combustion chamber for unwanted stuff...
Performance Products , in their paper catalogs , does say they have a tool rental program, so you have that as a back up..... Phil here at Fastlane may have that also... and he really ships fast....so check that if you are not going to make up a tool for this job.
But it would be much faster to find an injector and weld up a rod on it which can be used as a ' slide hammer extractor'....or if you already have a slide hammer just put a nut on the end of a stub which matches your slide hammer's threads....
Do you or your friend have welding capabilities ?

If anyone has a couple of bad injectors ( but with good outside threads ).... and will send them to me I will make up several of these items and we can just ship them around to whomever needs them....

gsxr · #33 06-30-2007, 03:38 PM

Quote:

Originally Posted by funola

Leathermang, from what you wrote I gather the prechamber has an internal thread that an injector can thread into? Is the thread just for prechamber extraction or is the injector threaded into the prechamber while in the head? I thought the injector threads into the prechamber collar only?

It surely cannot thread into both the collar and the prechamber. Not having seen these parts in the flesh (except the injector) it is difficult to visualize.

That is correct. The early (vertical injection) prechambers have fine internal threads at the top which are only used for the removal process... they allow an adapter to attach to a slide hammer. The injector itself has coarse threads and they screw into the coarse internal threads on the lockring, which is above the injector.

The later angled/inclined injection setup is totally different.

Here's a photo of the early/vertical pc's & lockrings:

funola · #34 06-30-2007, 09:51 PM

gsxr,

Thanks for the pic and the clarification. How is sealing accomplished at the internal and external threads of the lock ring? I know there is a heat shield and a lock ring washer. Is there an exploded view drawing showing the various parts and how they sit?

Quote:

Originally Posted by gsxr

That is correct. The early (vertical injection) prechambers have fine internal threads at the top which are only used for the removal process... they allow an adapter to attach to a slide hammer. The injector itself has coarse threads and they screw into the coarse internal threads on the lockring, which is above the injector.

The later angled/inclined injection setup is totally different.

Here's a photo of the early/vertical pc's & lockrings:

gsxr · #35 06-30-2007, 11:31 PM

Quote:

Originally Posted by funola

Thanks for the pic and the clarification. How is sealing accomplished at the internal and external threads of the lock ring? I know there is a heat shield and a lock ring washer. Is there an exploded view drawing showing the various parts and how they sit?

Basically there is no sealing of the threads. The prechamber seals to the cylinder head by pressure with no washer on OM60x engines... I think there may be sort of a seal washer used on the OM61x though. And as you noted, there is a heat shield which functions as a seal between the injector and prechamber. But that's it. There's no washer between the lock ring and prechamber. In the EPC engine service manuals, in groups 1 and 7, there are some exploded views that might help a little bit, but nothing that very clearly shows how everything is assembled. Once you take one apart it's fairly self-explanatory though.

#36 07-01-2007, 09:47 AM

Quote:

Originally Posted by jbaj007

The injector does not thread into the prechamber. It threads into the collar. Therefore an injector on a slide hammer doesn't work. Threads for the prechamber are 22 X1.0 which is much smaller and much, much finer than the injector threads.

An old large socket with cutouts that leave "ears" (with slightttt undercuts) has been made by some to remove the collar. Some use a large brass punch in the collar notches and tap it counterclockwise to remove the collars. Not elegant, and no torque values can be set when installing them this way, but works in a pinch.

so that's different in the 617 then? in the 603 the injector does thread into the prechamber... and you can buy the tool to get the locking ring off for about $55. if you use air on it it comes out easy

I can always borrow the hammer-tool from my indie. and if you have a good relationship with your local dealer I'm sure they loan it to you
tightening them back is a matter of "as hard as you can" that I've found to work well

gsxr · #37 07-01-2007, 10:21 AM

Quote:

Originally Posted by henrydupont

so that's different in the 617 then? in the 603 the injector does thread into the prechamber... and you can buy the tool to get the locking ring off for about $55. if you use air on it it comes out easy

I can always borrow the hammer-tool from my indie. and if you have a good relationship with your local dealer I'm sure they loan it to you
tightening them back is a matter of "as hard as you can" that I've found to work well

No... it depends what year 603 you are talking about. The early 60x with vertical injection has injectors with coarse threads that screw into the lock ring, as shown in the photo above, same as the 617. The later 60x with inclined/angled injection is totally different, it has injectors with a fine thread that screw directly into the prechamber, and different lock rings with a different tool, shown below:

funola · #38 07-01-2007, 10:31 AM

Hmmn... no sealing of the threads. Maybe that is why I see a slight fuel leak at the threads? What is the torque spec of the prechamber collar (aka lock ring?) on the 617 motor? I assume it has to be higher than the injector torque spec, otherwise when you unscrew the injector the collar could come out with it?

gsxr, is the pic you posted 617 prechambers and lock rings?

Quote:

Originally Posted by gsxr

Basically there is no sealing of the threads. The prechamber seals to the cylinder head by pressure with no washer on OM60x engines... I think there may be sort of a seal washer used on the OM61x though. And as you noted, there is a heat shield which functions as a seal between the injector and prechamber. But that's it. There's no washer between the lock ring and prechamber. In the EPC engine service manuals, in groups 1 and 7, there are some exploded views that might help a little bit, but nothing that very clearly shows how everything is assembled. Once you take one apart it's fairly self-explanatory though.

gsxr · #39 07-01-2007, 10:50 AM

The photo above is from a 603.960 (note there are six each, not five.

)

Torque spec is 100Nm for vertical, 130Nm for angular.

funola · #40 07-01-2007, 11:01 AM

I did notice 6 of them. They just looked so much like pics of 617 PC and lock rings posted in another thread. Do you have an old PC and lock ring from a 617 motor (with good threads)? I am looking for a set to make a puller for it. I have a small lathe with attachments that can cut external threads. I have never cut threads on the lathe so this would be a good first application. If it works out I can make a bunch of them that can screw onto a slap hammer and sell them at cost to whoever wants one.

Torque spec is 100Nm for vertical, 130Nm for angular.

[/QUOTE]

lietuviai · #41 07-01-2007, 04:58 PM

I think that's what damaged one of the cylinders and piston in my spare engine.

gsxr · #42 07-02-2007, 10:56 AM

Quote:

Originally Posted by funola

I did notice 6 of them. They just looked so much like pics of 617 PC and lock rings posted in another thread. Do you have an old PC and lock ring from a 617 motor (with good threads)? I am looking for a set to make a puller for it. I have a small lathe with attachments that can cut external threads. I have never cut threads on the lathe so this would be a good first application. If it works out I can make a bunch of them that can screw onto a slap hammer and sell them at cost to whoever wants one.

No, sorry, I don't have any spare parts. The adapter is available for somethng like $30 on eBay. Might not be worth the time to fabricate one...

Olivier · #43 12-18-2009, 03:32 PM

Hi Whunter, is this tool for the E300Turbo D as well?
It looks like my pre-chamber are like the one on the picture, with two U at the side, didn't see any splin today?
Was not really looking for this tho?
Thank you.
Olivier

whunter · #44 12-18-2009, 09:22 PM

Quote:

Originally Posted by Olivier

Hi Whunter, is this tool for the E300Turbo D as well?
It looks like my pre-chamber are like the one on the picture, with two U at the side, didn't see any splin today?
Was not really looking for this tho?
Thank you.
Olivier

The same tool is used for extracting the pre-chamber on both.

Home Made Special Tools, This is where members can share how they made special tools
Home Made Special Tools, This is where members can share how they made special tools

gsxr · #45 12-18-2009, 09:45 PM

Quote:

Originally Posted by whunter

The same tool is used for extracting the pre-chamber on both.

That is correct. Once the lock rings are removed, the same tool (slide hammer + adapter) is used to extract the prechamber.

The lock rings above the prechamber can be two different styles, and there are two different tools. Most MB diesels through 1987 are vertical injection and use the "pin wrench" tool. All models from 1988-up have angled / inclined injection and use the "splined" tool.

Your 1997 OM606 engine has inclined injection, and requires the splined tool shown in post # 37 on the previous page, to remove the lock ring. Then you use the slide hammer + adapter (shown below) to extract the prechamber.