Dun dun dunnnnnn. Like many others my exhaust is leaky and loud. Since I was starting a project on the air/fuel system under the hood I figured why not take care of that exhaust too. As I started checking things out I found this missing stud (pictured below), on drivers side, and the others on the drivers side are rust out pretty bad. Some of the bolts might need to be cut off. The passenger side is not so bad. The missing stud broke off flush with the manifold so there is about 1/4" sticking out from the head. So I realize this is going to be a real pain in the ass, I just dont know how big of a pain in the ass. After some research I found that a few people detached motor mount(s) and jacked the motor up a bit, while other had to remove the heads. I've never changed these studs on any car before... Anyone have any advise or experience to share?

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I think Martin is going through the same thing on his 300SEL 3.5 but the heads are off. I hate to say it but to do it correctly you will most likely need to pull the heads-there is just not enough room to work.

__________________
Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT

Invest in a stud removal tool that you can use with a 1/2" drive ratchet.
It is easier to do with the engine out but not that much easier. undo the engine mount bolts (1 each side) and place a jack under the oil pan with a block of wood on top of it to protect the pan. lift the engine about 2 1/2 to 3" and you can reach all of the nuts. They are 12mm heads with a 8x1.5 thread . tale them all off or break them if they do . then remove the manifolds and use your new tool to remove the studs from the heads . Buy a full set of new studs and and nuts,plus gaskets and reassemble . You will be set for another 40 years.

Great, thanks guys. I think with mermad's plan that will work. drivers side is pretty roomy and with the battery out i think passenger side will be fine too.

depends on which stud on the passenger side. I did my 1st valve job on a v8 after snapping my first stud on a v8. But I didn't think to lift up the motor. That would indeed work (though you might need to disconnect the transmission cooler lines).

-CTH

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- cth350@gmail.com
http://www.111lakeside.com/

You might also get a Helicoil kit and replace the studs.

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

How does this stud removal tool work? How does it prevent a stud from breaking off flush? If it really works it's worth it's weight in gold!

Are the threads really 8x1.50? Just because that's rather uncommon, 8x1.25 and 8x1.00 seem to be common.
Thanks,

Csaba

I found a few videos online. seems the safest ones have the ratchet attach directly on top, instead of to the side. and instead of a ratchet use a t-bar so pressure is applied evenly (or as close as it gets).

I also found that some people heat the stud with a torch and stick wax on it, which gets drawn into the threads and acts as a lubricant.

I havent tried anything yet but this is what my research has produced...

I wouldn't heat the stud. Hot steel in an aluminum head might be bad. I had some snap in the head, those needed me to drill into them and remove with a stud extractor that is totally different (had to do this when some lug studs snapped too). I'd say just be careful but the stud probably won't break in the head. Usually it breaks on the threads at the manifold where it was overtorqued. That's why OEM nuts are a soft copper crush nut!!

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Thanks Tomguy. I ordered the copper nuts from the good ole Fastlane, but im not sure where to get the studs. My search online has not produced anything... should I goto Mercedes?