I am finishing up the installation of a new-to-me (ex-Sixto) #20 head in my '87 300D Turbo (W124, OM603). The pins (which came from my old #14 head) that hold the upper chain guide are very tight in the new head. In the picture from FSM the pins are #221 (upper) and #222 (lower).

Without removing the radiator and condenser, there's not very much room to swing a hammer to drive the pins into the head. I managed to get the upper pin in using a large c-clamp as a jury-rig press. The bottom pin seems to be even tighter and I don't want to break anything. The pins are a pure friction fit; you can feel that the diameter increases a tiny bit at the outer end.

Would it help to put the (steel) pin in the freezer for awhile, in hopes it will shrink a bit? I could also heat the (aluminum) head with a heat gun to hopefully expand the hole. Think that might help? Wish there was an insertion tool for those pins to make insertion as easy as the puller made removal.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Removing the radiator is not a large task as the cooling system is already drained and the condensor can be slid to the side- a long punch used to drive in the pin.

Yep, when I put them in my 601 they were tight. I thought I was going to break something too, I had the motor out when I put the pins in.

Solution: I gently chucked the pin in my drill press and polished it with emery paper. It took off just enough dirt and corrosion to allow me to tap the pin into the head.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

anyone know where to buy replacement om603 guide pins?

Dealer

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

On one job, I had to drill access to the back side and drive the pin out with a punch. I replaced that pin with a hardened bolt and nut.

I am not suggesting that as a good option if the correct pin can be installed. But if you had to really bugger things up to get it out, it is an option.

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO