Front strut nut removal issue

[Marcusd]

I have hit a bit of a problem when trying to replace the dampers in the front struts and wondered if any of you guys had any ideas?

On my '95 525i E34 the top strut nut is recessed too far in to get an open ended wrench on it. I tried a 7/8" Lambda/Oxygen sensor removal socket so I could get a 6mm hex down the middle to hold the damper rod as I undo the 22mm nut - no joy, the 7/8" socket is too wide to fit in the rdcess where the 22mm nut sits.

I have an Air Impact wrench which even though it fits does not seem to have enough torque to budge the nut (I am guessing it is either rubbish or faulty though as I can stop the socket turning with my hand when it being fed with 100psi! :) Mind you it was cheap!)

In the UK, I can't seem to find a 7/8" or 22mm spark plug deep reach socket with a hex head so I can turn it with a wrench on the hex end whilst still being able to get a 6mm alen hex key down the hole in the middle to hold the damper rod.

Here is the nut...

7507

[Bill R.]

If your replacing the struts anyway and you already have them off the car. Then just grab the damper shaft with some vice grips and then use an impact on the nuts while holding the vice grips to keep the shaft from spinning

[Marcusd]

I tried using mole grips as tight as I could get them but the damper rod still spins. If my air impact wrench had more torque than me being able to resist it spinning by hand, I reckon that would do the trick. Suppose you get what you pay for with some cheap tools!

Plan B is to grind off a bit of metal from the outside edge of a 7/8" lambda/O2 socket and try to hold the damper rod with a 6mm hex in the hole through the top of the modified socket!

Time for bed now on Uk time so will have another bash in the morning. I will have another go with vice/ mole grips holding the damper rod though. This time I will make sure there is no oil on it! ;0)

[Marcusd]

The nut is so tight that it must have been done up with an air impact wrench. I can't get enough grip on the damper rod with vice grips and as my air wrench is crap I am running out of options.

I modified a socket so I could fit a 6mm hex key the side but this just stripped the hex hole in the top of the damper rod. I tried using an electric drill to act as an impact wrench and even an 800w drill couldn't budge it!

Plan c time then, I will double check the compressor to make sure it is really supplying 100psi then go out and buy a better air impact wrench!

All because strut inserts would cost £330 at a garage rather than £110 if I do them myself! ;0)

[John B.]

100 psi isn't going to cut it. When I need to break something like that loose with the impact I run the air pressure up "well" over 100 psi.

[BennyM]

When I replaced mine, I took the struts to a friend who had a really powerful air wrench. That was the only way I could get the nuts to come off. I suggest you find a more expensive tool :)

[leicesterboy15]

Have you tried heating it?

I have a cheap electric impact wrench that goes to 340nm, no idea what that is in PSI.

What torque are these nuts tightened to?

[ahlem]

narrow cold chisel and split the nut. Or, you can also use a 1/2" drive socket with flats ground on the OD held with a wrench and use a 6mm 3/8 drive allen socket down the middle. The down the middle tool will vary with the brand of strut insert.

[Marcusd]

Thanks guys, got it undone in the end by taking them to someone with a wrench as powerful as the one which tightened the nut the last time it was done.

I tightened them back up with my modified O2 sensor removal socket and a hex key.

My impact wrench had no chance undoing a nut which was last tightened by a lot more powerful wrench.

[genphreak]

Its actually the zine plating and corrosion that over time (and worse w salt) chemically freezes the threads of the nut. These are seldom done up that tight, they just lock up with time.