Trying to adjust valves on an 85 300D, and the first one i tried,# 1 exhaust, went from a little tight to totally tight. Tried turning the cap nut clockwise and counter clockwise, made no difference not even a .002 blade will fit the gap.

Finally called the local Mercedes dealership to ask them whether clockwise or ccw to loosen, and they said counter clockwise. So i turned it a bunch, still totally tight.

Finally the cap nut came totally off, and the gap is still zero.

Not sure if i will even be able to get that cap nut back one, let alone get the proper gap. May have to send the car to the crusher.

In the context of valve adjustment, that is incorrect. CCW (viewed from above) turns the cap nut off the valve, which reduces the valve clearance.

Where is the cam lobe?

Thanks for the reply

Cam lobe is approximately opposite where the round part contacts the cap nut, as shown in the diagram in the crappy Haynes manual i am using.

Not sure if i will ever get that cap nut back on, it is wedged under the rocker arm.

Sounds like you may need the third wrench.
http://www.peachparts.com/shopforum/diesel-discussion/180280-home-made-valve-adjustment-wrench-info.html



http://www.peachparts.com/shopforum/diesel-discussion/107729-valve-adjustment-om615-616-617-fyi.html

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1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

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Now i know . Never ask Mercedes for technical advice, and clockwise loosens.

Clueless how to get that cap nut back on. it is wedged at an angle under the rocker arm. Even if i can pry it into place with screwdrivers and vicegrips, i'm totally confident that it will screw on cross threaded as usual.

What to do???

Cap nut is off & @ a wierd angle. What do i have to do to get it back on the valve?

If the valve is real tight, and you cant budge it, first make sure that the rocker is on the base circle of the cam. If you're still stuck you may try be able to get the rockers out. The 10 rockers ride on rods held in place by racks bolted to the head. I think an M8 or M10 allen head cap screw holds them in, 1 per support, 3 on 1, 2 on the other. After removing the bolts that hold the supports on to the head, you should be able to tap the rack free with a brass drift or a wooden hammer handle.

The valves on my 616 have a right hand thread, so turning the lock nut CW (to create clearance w/ the cap nut), and then turning the cap nut CW will shorten the assembly and create clearance between it and the cam.

Find out the proper torque to tighten the bolts when you put them back in. It will be easier if you adjust the cap nuts to create clearance w/ the cam when you put the rack back in.

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CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

Thanx, if it gets light out & quits rainning, will give it a try.

38 N-m for rocker brackets in the NA head. Don't know if it's different for the turbo head.

I hear the camshaft can crack if loaded wrong. Exercise care putting the rack back in. You don't want to be jamming the rack back in with a lot of lift on the valve. Others can clarify any precautions needed. Be sure those brackets are tight before you start it again.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

I got a call, verifying the cap is back on..

He is working on the valve adjustment.

This was an abandoned vehicle bought at auction.

Overall (previous owner) maintenance condition = seriously neglected/ignored until it shutdown.

We had a nice chat about valve face - valve seat carbon build up, Italian tune-up between valve adjustments = the need of several back to back valve adjustments in the same day/week.


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__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

It's back together, running a little more smoothly, but needs a window, draining the algae laden fuel & other stuff before i can drive it enuff to require the follow up valve adjustments.

Um could you explain this better?

Edit. Nevermind... moon's explanation does a great job.

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