Front strut nut removal trick

[m3f_drtwofish_aac1f2a5e1]

Hi all,

I did my front struts this weekend, and ran into some difficulty with getting the strut shaft nut off & on. I've seen some cautions about using an impact wrench (and don't have one anyway), and BavAuto recommends using a combination of spark plug socket + wrench on the flat bits and a 6mm allen key to hold the inside of the shaft. That worked well to get the old one off, but the new nuts were a size bigger (22 mm) - and they don't make 22 mm spark plug sockets!



I ended up finding a new type of ratchet at Lowes that has a hollow head - they call it MaxAccess or something (actually I think that's Craftsman's name, but they didn't have a 22mm socket for it). That combined with a 6mm allen key + vice grips did the key for reinstallation. I also discovered that you can't use an allen key with a ball-end; they get stuck in the shaft due to the small mating surface. I think next time I do it I'll take my 3/8" drive 6mm allen and just dremel off the ball end to avoid using vice grips. Here's a pic of the final setup re-enacted after getting the coil and shock mount off - let me know if you have questions, as this job's lodged in my brain for the time being:



http://i.imgur.com/MBfroNM.jpg?1

[m3f_englishtom_70cc2c7eca]

Electric impact FTW. this idea works until you strip the allen key hole which can be very easy to do. you can also put a rag over the shaft and use a pair of vice grips far enough up the shaft that if it does snag it wont ruin the shock.


Also once the nuts off clean the threads with a tap and die set to remove the rust that can build up on the top

[m3f_drtwofish_aac1f2a5e1]

I haven't tried the impact wrench, but BavAuto claims it can break the strut rod.

http://blog.bavauto.com/4383/bmw-shock-strut-and-spring-replacement-installation/


No data from me one way or the next on that, but it didn't seem like it was worth the risk. Using the ball-end allen key did strip the inside of the shaft a bit, but using the solid allen key worked just fine - no slippage at all. Isn't that what the keyed inside is designed for? I did try using vice grips to remove the old one, but they wouldn't bite strongly enough to stop the shaft from spinning.


Why bother cleaning the threads if you're using a new nut?

[m3f_englishtom_70cc2c7eca]

it'll never break the rod. In the 8 years of working in a shop i've done and seen hundreds of struts done with an impact.


The allen hole is designed for that but they do strip out


and if youre reusing the strut the top of the threads are exposed and sometimes build up rust. if you remove that the new nut will spin on a lot easier without having to hold the strut rod as tightly

[m3f_Magic M3_88afc92f23]

OP: There is nothing wrong with using an impact for disassembly. The place you want to use caution is upon reassembly wih the new parts. Yes, a pneumatic impact gun can and will strip threads on a strut! (Ask me how I know). It is a pain to cut the nut off with a dremel!



One good method is to wrap an old chunk of belt around the shaft of the shock then carefully clamp with a vice grip and tighten with a deep well socket by hand.



Another that is safe as well.....simply use a 18v cordless impact wrench to "zip" it down. These cordless guns do not have excessive torque and will not strip the threads.

[m3f_drtwofish_aac1f2a5e1]

Good to know, thanks. I was installing new struts so didn't have to hassle with old threads!

[m3f_propchef_a4c19a6d03]

OP: There is nothing wrong with using an impact for disassembly. The place you want to use caution is upon reassembly wih the new parts. Yes, a pneumatic impact gun can and will strip threads on a strut! (Ask me how I know). It is a pain to cut the nut off with a dremel!



One good method is to wrap an old chunk of belt around the shaft of the shock then carefully clamp with a vice grip and tighten with a deep well socket by hand.



Another that is safe as well.....simply use a 18v cordless impact wrench to "zip" it down. These cordless guns do not have excessive torque and will not strip the threads.



I used a method from one of Cal's threads: a piece of rubber hose sliced open. Grips tight and cushions the grip from the vice grips.

[m3f_RND1_4460857ea5]

I recently installed new struts, top hats, and all new hardware. I wrapped the shaft with several shop rags and held it with a pair of channel locks, then used an electric impact to remove and reinstall. Not so much torque as an air impact. Shaft was clean, no evidence of the channel locks.



I'm curious how they would do this job at the dealer? Only downside with impact gun at home is not being able to check actual torque setting.

[m3f_drtwofish_aac1f2a5e1]

I'm curious how they would do this job at the dealer? Only downside with impact gun at home is not being able to check actual torque setting.



This question was lodged in my head as I was browsing the aisles at Sears and Lowes...what IS the official way to do this job?



I'm surprised (but glad) the vice-grips method worked for so many of you - my buddy and I tried removal with both a big pair of vg's and the biggest channel-locks known to man, and couldn't keep a grip on the shaft. So to speak.

[m3f_hcaleman_e2771eaa1d]

Wouldn't a 22mm O2 sensor socket work?

[m3f_fiveightan_7e37700daf]

I've always used an old piece of belt with vice grips. Never had the shaft slip, never had an issue getting them off. I use air and hold it steady with the vice grips.



That hex hole in the shaft does strip quite easily.



Be careful with air tools though, you don't want to spin the shaft on any strut that you care about. It'll mess up the seals and the damper will fail in short order.

Wouldn't a 22mm O2 sensor socket work?

The walls on the socket are much too thick if you're working with OE strut mounts. Even a 22mm impact socket is usually too thick. You have to use something with thin walls.

[m3f_vmbray_980ce7cf9e]

Just pulse the impact, set it to low and pulse it. When you get close use a 22 socket with vise grips and feed a 1/4" Allen socket down inside the 1/2" socket. Torque using Jedi torque sense.


Sent from my DROID X2 using Tapatalk 2

[m3f_drtwofish_aac1f2a5e1]

Just pulse the impact, set it to low and pulse it. When you get close use a 22 socket with vise grips and feed a 1/4" Allen socket down inside the 1/2" socket. Torque using Jedi torque sense.



Sent from my DROID X2 using Tapatalk 2



This all seems a lot of work compared to just using a passthrough socket :kittyshifty:

[m3f_YAOGinanM3_a6dcbd0afd]

This all seems a lot of work compared to just using a passthrough socket :kittyshifty:


The average home mechanic would not have a passthrough socket this large even if they knew what you were talking about. The problem is what do you do when you are looking at an adjustable coilover strut or damper or a damper without a keyhole? You know like just about every adjustable Koni or similar damper with an adjustment knob or rod out the top of the shaft.


The best thing I have found is to just use a good 1/2" 750-850ft/lb gun and make sure you dial UP the torque to max. use short sharp pulses to break the strut nuts loose. If you have a good 1/2 gun will have a torque dial and with good air volume and correct air pressure the pulses are hard and fast enough that you will not rotate the strut rod. I've done it this way 100's of times over the last 35 years with no damage or leaking strut seals. I learned this from an old school dealership Porsche mechanic.

[m3f_drtwofish_aac1f2a5e1]

The average home mechanic would not have a passthrough socket this large even if they knew what you were talking about. The problem is what do you do when you are looking at an adjustable coilover strut or damper or a damper without a keyhole? You know just about every adjustable Koni or similar damper with an adjustment knob or rod out the top of the shaft.



Well, that's why I started this thread



I'm an average home mechanic, and I don't have a compressor powerful enough to drive an impact wrench. The $50 ratchet solution was much cheaper for an OEM-to-OEM strut replacement. Not intended to solve every aftermarket/coilover application...just a cheaper (and arguably less risky) alternative for folks without an impact setup.