how to loose the top nut on the front shock absorber with a stripped head?

[colin888]

Hi Guys,

I tried to replace the front shock absorber on my 1999 ML430. The top nut on the front shock absorber on the driver side was stuck. After applying the PB blaster penetrating oil on the nut, I still can't loose it. After trying a couple of times, I found the head of the bolt was stripped by the open end wrench. How to loosen the top nut with the stripped head? Thanks in advance.

[colin888]

BTW, I tried the Craftsman Bolt-Out damaged Bolt/Nut Remover Set like below. However, it won't work since the direction of bolt seems be reverse. Also tried the vise grip, but I won't be able to hold the handle when loosening the nut.

[Noodles]

I have a set of those made by Irwin. They should work. The shock nut at the top is a normal thread and turning left will loosen it.
Take the Bolt-Out that is the right size and gently tap it in place with a hammer. Make sure it is really biting onto some of the stripped nut before proceeding. Then use an impact wrench or ratchet to loosen it. The metal shaft of the shock will try to spin. Put a vice grip on that to keep it from spinning.

Option B would be to just grind it off seeing as you are replacing the shock and need a new nut for the shock.
If it were mine I would grind it off using my air grinder and a conical bit like one of the ones pictured here.

[43sqd]

Use a Dremel w/cut-off wheel on the side of the nut.

[Noodles]

That would a great job also seeing as many people do not have air tools.

[pte]

Hi Guy's here some different tips
Machinist's Workshop magazine
recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional machinist.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 pounds
The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid

#2
I have also drilled (3) 1/8th " holes down one flat of the hex then hit it with a chisel to split open the nut .
#3
Remove the wheel Remove the 5 plastic nut that hold the plastic inter
fender tub. Takes 5 Minutes, Then you are looking straight in at the shock stud. You now have excess to the stud . you can use a hand Hack saw or a Electric saw zall. saw the nut & stud clean at the washer. When you finish the install . cut the new shock stud off at the top of the new nut . use a dab of grease on top & cover it with a plastic cap Cheers _PTEngineering

[43sqd]

Originally Posted by pte

The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.

I suggested this 2 yrs. ago but it wasn't even commented on.

http://www.benzworld.org/forums/w163...ml#post4536105

[pte]

43sqd ;
The article just puts some validity & Numbers to what you & I already Know !

Pax Vobiscum
_PTEngineering

[scottbordo@hotmail.com]

Did you try a 6 sided socket vs 12?

[ruggler]

Originally Posted by pte

Hi Guy's here some different tips
Machinist's Workshop magazine
recently published some information on various penetrating oils that I found very interesting.
Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional machinist.
They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a
"scientifically rusted" environment.
*Penetrating oils ........... Average torque load to loosen*
No Oil used ................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ...............127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix............53 poundsThe ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.
Note this "home brew" released bolts better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results.
Note also that "Liquid Wrench" is almost as good as "Kroil"
for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can also use ATF and lacquer thinner in a 50-50 mix.
*ATF=Automatic Transmission Fluid

#2
I have also drilled (3) 1/8th " holes down one flat of the hex then hit it with a chisel to split open the nut .
#3
Remove the wheel Remove the 5 plastic nut that hold the plastic inter
fender tub. Takes 5 Minutes, Then you are looking straight in at the shock stud. You now have excess to the stud . you can use a hand Hack saw or a Electric saw zall. saw the nut & stud clean at the washer. When you finish the install . cut the new shock stud off at the top of the new nut . use a dab of grease on top & cover it with a plastic cap Cheers _PTEngineering

Sorry to hyjack this thread but do you think this mix would work to get my precat passenger side o2 sensor out without taking it to a shop? I dont have access to a torch anymore.