Hey Guys,
I must be losing my mind!
I cannot for the life of me figure out where the rack pin adjustment is. I tried searching the threads, but no luck.
Does anyone have a drawing with instructions?
I'm sure you old-timers are sick of hearing this question, but i sure could use a hand.
Thanks.

Its on the back of the injection pump, twoards the firewall. It is a bolt with a locknut on it, I think 14 and 12mm.

Ed, I'm in the same boat you are. I looked just today for this infamous rack pin on my 1984 300 D Turbo. I checked all three sides that I can get to and couln't locate. Anybody have a pic of a drwaing or something.

Jim A.
1984 300 D Turbo

Here is my crude drawing/diagram.. looking from the drivers side of the car..

Thanks Guy's
It's alittle late in the evening now, but I will take a look again tomorrow.

Ok no snikering but this is the first time ive heard of the rack pin
so my ? is just what does it do and how do i check it to see if its working right thanks Bob se,ks.

Hey Bob,
Im still learning about diesels myself.
It has to do with injection timing at idle, so if your diesel is shaking at idle this can be used to adjust that rough idle away.

Hi guys

Don't worry!
Not all cars have these idle rack adjustment bolts.

I have an 82 240D and a 81 300CD and neither of them have it. The back of the pump is just an anodized pressed steel cover with the shut off valve on it. Nuttin else...

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

Greetings,

I'd say in the last couple of weeks the idle has gotten a little rough at idle coming off the expressway to a stop sign or sitting at the stoplight either on a cold or warm engine. Reading the posts I decided perhaps that the rack pin may require a little adjustment. Seems like the pin is almost at it's complete travel inward as there are no more threads showing on the locknut. It did smooth out a bit turning it in but I think just a tad more will do the trick. Hey Bill, where can I get one of those bullet proof pins you spoke about? Mine is the original I believe as I pulled it out and it looks to be somewhat hammered on the end a bit. With a little bit more travel I think my Baby will just purr like a kitten. I didn't see it listed on Fastlane so if you have a p/n I'd appreciate it.


Thanks,

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

Greetings Bill,

You aren't going down to your local Mercedes dealer are you? Have to admit, that is my biggest drawback living out in the middle of nowhere, no Mercedes dealer for over an hour and a half away. What are you guessing the cost to be on this little guy Bill? Are you sure there isn't one on Fastlane or the dreaded Mercedes shop with it's shipping cost. Wish they'd get the no shipping cost down on orders over $50 as I always order at least $100 or so when I do place an order. Let me know Bill, as well as how I can pay you if it won't cost both arms to do it.


Thanks,

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

D2030-17407

If you go to Fastlane, choose your car (82 300DT)
and go to Fuel Injection, it's called EHA Valve

That's Fastlane's part number. I lost the bag that my new rack damper came in.
I bought a new one after weeks of wondering why my coupe shakes like a truck...

That + a combination of other things helped a lot.

New engine mounts + tranny mount while I was at it.
New air filter
New Rack damper
Lower Idle (I don't know why...)

__________________
2008 BMW 335i Coupe

Greetings,

Was the replacement Rack Pin adjuster gold or silver in color? They have said several times on this post to get the new version which is gold and less susceptable to wear I guess. What the heck does the EHA stand for? I guess if it's the ole silver design it would probably be good for another 199000 miles, assuming the one I am replacing is the original. I would imagine that something apparently tapps against this constantly that causes the hammered wear look on the end as it loses it's adjustment. Thanks for you reply

Thanks,

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

I thought mine was the old one. However it wasn't. It was actually gold in color. Just because the bolt was badly oxidized that it looked silverish in color.

The one that I bought from Fastlane, which is currently in the Injection Pump, is gold in color.

I looked at both of 'em carefully. The old one was actually almost 1mm shorter. Maybe the spring was actually weaker too. I never thought it was a spring inside.... I thought it was a solid bolt.

Greetings and Thanks for the help,

If the new one you got was gold in color then it probably is the hardened new design. I think not only the constant pounding of the rack causes the pin to flatten out on the end but also weaken the spring over time. Sounds like a great price as well. Did the new pin come with a sealing o-ring as well?

Thanks,

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

I think I found it because someone posted the part number for it.
I could never figure out what EHA Valve is.... I'm still trying to get hold of a W123 parts booklet or something like that with every single part and its number.

it didn't come with the O-Ring, so I just reused my old O-ring because there was no signs of a leak anywhere around the rack damper pin.

I was expecting oil to leak out of the injection pump, good thing that nothing leaked and made the job a little bit cleaner.

__________________
2008 BMW 335i Coupe