I've been meaning to change the struts on my rear door on my wagon and they use triple square (12-sided star) sockets. I bought a decent looking set of sockets but the screws must be factory tight because the 8MM socket is just stripping the teeth!

Are there any suggestions on how to get them out? I am really preferring some standard hex bolts right around now. If I can get them off, I will just get a set from the hardware store and so it's easier in the future to deal with.

Normally I would drill them out. There is a 'drill-out' or 'screw-out' kit at Sears I'm thinking of acquiring anyway. Any other least-painful and least-stressful approaches?

The very reason that the "triple square" is utilized is to effect significantly higher torque levels. The head can take all the force utilized to install the fastener to the specified torque. There are 12 load surfaces to take the force..........far better than any hex could ever do.

If you're stripping the triple square, I would check to see if you had the correct size and the fit is proper. Also check to ensure that the bit is going all the way to the bottom of the available space.

Finally, are you positive they are triple square screws and not Torx? Such errors have been made before.............

If all of the above has been verified...........carefully heat the fastener with a propane torch. If you just heat by the head...........be patient because the heat must travel down the fastener and heat the entire length. You wish the fastener to lengthen slightly to unload the head. I'd wait a good five minutes or so with the torch. A huge flame is not necessary or desired.

Once heated properly, the fastener is easily removed (provided you haven't totally stripped the head).

At this point I'd like to assume the heads are totally stripped. I just want to get them out by whatever force possible that won't take me 2 hours.

It's definitely a triple square. No confusion between a 6-sided bolt and a 12-sided one. And the 9MM doesn't remotely fit. 8MM fits perfectly, but the ratchet (a torque wrench) just moves without any grip and I see metal shavings on the socket, stripped from the bolt.

A torch isn't an option, as I have the upholstery in the very close vicinity. I'd like to find out what the best 'by-force' options are, that are fairly reliable and straight-forward.

When you find a "by force" option that is reliable and straight-forward, please let me know.

Your best solution, with whatever you choose, is going to be heat...........but, I realize that your mind is closed to that possibility............so, I wish you the best of luck in your endeavor.

If you can on the non stripped one, you may need to use an impact to break it free. Hopefully someone didn't put loctite.

Take a die grinder with a cutting disc and cut the head off then it will easily unscrew. I have found that it works best if you use a hand held impact with the proper bit to break them loose.

__________________
Jim

x2

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Hi
These are special bolts (in addition to being Triple-square) that you wont find at a hardware store.

The bolts on my 85 were also super tight. I had to clean out the opening and then drive in the T-S socket with a hammer to seat it before I could break it loose
Joseph

I can see why heat would not work, the bolts are behind the Headliner. maybe if the rear of the Headliner was dropped down, you could get better access to it. the bit size is definately a M8.

I just removed 2 of these at PNP for the first time. just make sure the bit is well seated, the one side was in pretty tight, and gave me some trouble. just make sure you are at the right angle to the bolt head. I almost stripped this side.

This bolt isn`t a run of the mill Hardware store bolt. definately a Dealer item.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I had the same situation. The problem is your working through a small hole in the headliner. I tried a hand held impact driver, with no luck so without pulling down the headliner it seemed I was out of options. In my case the back hatch stays up unless the wagons parked with the front up hill.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

The "drill-out" or EZ-outs require some finesse to get to work properly, particularly on frozen/stuck bolts. Have you tried something like an electric hammer drill set on reverse with the proper size bit (or by now an oversize bit?)

If you go with a drill-out approach, I'd recommend re-tapping the holes with the appropriate sized metric tap to clean out the threads. Ensure the threads are correct with the replacement bolts on a nut or off-the-car piece of metal before going this route.

I have a special triple square bit set ordered online. Passenger side worked fine after I hammered it in a bit. But the driver's side was worn down a bit and so I've resorted to drilling it out. I drilled about 1/2 inch through and at this point and will try with consecutive bits when I can.

Right now, just one new strut works fine, better than none.

Once you get the head off the threaded part should just unscrew.

The MB p/n for new fasteners is:

123-990-01-29.

__________________
Jim

I've been through this enough times that I'm going to get a screw/bolt drill-out/extractor set as well as a die/tap set. 30 year old cars seem to easily have stubborn bolts quite a bit.

Did a search on that part#. $10.39. Wow!!!
http://parts-planet.us/products.html?action=showitems&keywords=&begin=1097&maker=7

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works