I'm not sure about adjusting valves on a 450??? On a 280 M110, adjustment nut is 17 mm. It is lefty loosy, righty tighty as far as moving the adjustment. In other words left or counter clockwise will back out the adjustment. This reduces the clearance by pushing up on rocker. Right or clockwise will move the adjustment in and increase the clearance. People have done this with a conventional open end wrench or a crow's foot wrench. It tried it that way and was able to do a few but I was afraid of stripping the nut or doing other damage. The adjustment doesn't (or shouldn't) turn easily. So I broke down a bought a Hazet 17 mm valve adjustment wrench. That made everything go much easier and faster.

 

There's a special tool. I have one, and I'm on the south side of Philly. PM me and maybe we can arrange something.

 

Will do...

 

 

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Hi Fonzi,

Is that a Hazet? Could you tell me the part number? Thanks

 

Thanks, good to know!

 

Was it necessary to loosen that 24mm seat below rocker adjuster to get the adjuster to move?

 

No.

 

Most are 17mm. I think I might have seen a 14mm on the early 450sl 3.5
There are many different types of adjusting tools most are hazet but snapon and mac also make them

 

I've used a 17mm crows foot but I would like a set of those Hazet tools - just because

 

No wrench is needed at all to adjust valve clearance on an M117. Adjustment is made by changing the thrust piece on top of the valve.
You do need a special gauge and a valve spring compressor tho.





Fish

 

I disagree.

The manual recommends checking valve clearance every 10,000 miles on the M116.982 and M117.982. Adjustment is done with the pictured wrench and feeler gauge.

Adjustment is easier with the Hazet tool versus crows foot. The Hazet tool keeps the open end squarely aligned with the adjuster.

 

Oops, I thought the change was in '74... never mind





Fish

 

Easy to tell if it is hydraulic. If it has cis it is hydraulic if it has electric injectors it is adjustable.

 

My factory service manual for M116 and M117 engines specifies .008 mm clearance for intake valves while the Encyclopedia Germanica Volume 107 specifies .10 mm. Can anyone clarify this discrepancy. Also, the factory service manual states that the valves should never be adjusted hot, while the EGV 107 provides clearance values for hot adjustment. Again, why the discrepancy?

 

05.1-210

.08 intake; .20 exhaust

Really have to pay attention to cam position and what valve it is that is being adjusted. I print out this instruction when I do this job and make notes on figure 5 as I accomplish each adjustment.

I did it wrong the first time, got it right the second and was very surprised how much smoother and stronger the engine ran when the valve train is properly adjusted.

 

Your attachments are directly out of the factory manual and confirm the .08mm intake clearance but I'm still wondering why the EGV 107 provides a clearance of .10mm. Not a big deal, but surely someone knows the answer.

 

.



The EGv107 has a lot of links. A link to the particular post or even the thread in which you found it would be a great first clue...

 

mpwood,

I found the spec you are referring to in a later edition of the M117 Service Manual. I have this edition only in computer form; the earlier edition in print and scanned to pdf. I lean towards the older edition for our 1973 models because they were published when the cars were built and I like the pictures and detailed instructions better in many cases.

I think either spec would be fine as it is probably impossible to discern 2/100ths of a millimeter with a feeler gauge. I'm sure you would agree and simply want to possess the correct information.

Incidentally, the two editions of the M117 Service Manual referenced above have confusing differences in setting ignition timing. Both end in the same result but the methods are different.

 

Your probably right. In fact most feeler gauge sets do not have an exact .008 & .020mm gauge. I have a made in China gauge that has a .008 & .020mm feeler that shows a corresponding inch value of .003 and .008 but but my quality made in the USA gauge (albeit 50 years old or more) shows that .003 is .078mm and .008 is .203mm. But based on one millimeter being .03937007874 of an inch .003 inches is .0762mm and .008 is .2032mm. Close enough!

 

mpwood,

Check your decimal places - (0.08mm and 0.20mm versus 0.008mm and 0.02mm)

 

Your probably right. In fact most feeler gauge sets do not have an exact 0.08 & 0.20mm gauge. I have a made in China gauge that has a 0.08 & 0.20mm feeler that shows a corresponding inch value of .003 and .008 but but my quality made in the USA gauge (albeit 50 years old or more) shows that .003 is .078mm and .008 is .203mm. But based on one millimeter being .03937007874 of an inch .003 inches is .0762mm and 0.08 is .2032mm. Close enough!

 

Do I need the hazet tool for an 85 380sl?
Thanks.

 

Do I need a hazet tool for a 85 380?
Thanks

 

No. Yours are hydraulic.