'99 S 70 Rear Shock Change

Post by **E Showell** » 27 Jun 2015, 16:25

So, I've read and printed cn90's repair guide for a rear shock change and am proud to say that following his sage advice about having some patience with the two shock mount bolts, I actually manage to remove one side without breaking the bolts or stripping the captive nuts. Lots of PB Blaster -- tighten, then loosen a few turns at a time and "waking up" up the bolts with a little gentle pounding on the heads with a rubber mallet from time to time proved just the ticket to removing the bolts whole. (I've only managed one side so far).

The problem has been removing the 18 mm nut on the bottom mounting stud. I've bathed it in PB Blaster, whacked with the rubber mallet, but still no joy. I figure I'm going to get out the small torch. I need to save the stud. Should I be trying to heat the stud or the nut? I'm sure I'll get some smoldering rubber since there appears to be a seal around the perimeter of the mounting hole in the shock.

Anybody else got any bright ideas for removing this nut? Thanks.

Kudos to cn90 for the tips on taking it easy on the shock mount upper bolts. Last time, I left the job for my mechanic and he broke the nuts and had to replace them.

Post by **kahl** » 27 Jun 2015, 18:32

Heat the nut so that it will expand. Have a damp rag ready to douse any oil that ignites. Nice and hot should do it!

Post by **abscate** » 27 Jun 2015, 18:38

Remember to give PB days to work it's magic

Post by **MrAl** » 27 Jun 2015, 20:42

Hi,

If nothing else works there are some other ideas for general tough nut removal, when possible.

One is to take a regular hard steel center punch with a reasonably sharp tip and hold it against the nut, near one of the hex vertexes but not too close to the edge of the vertex, such that the point still has plenty of meat to dig into. Holding the body of the center punch as close to a tangent to the bolt diameter as you can get, tap the center punch repeatedly with a steel head hammer, hard but not too hard as the center punch can chip and send sharp metal pieces in various directions, and of course wear safety glasses.
Applying abrupt force like this along the tangent helps to free the nut from the bolt, and of course you should be using the punch to 'push' the nut in the direction that would tend to loosen it.
If you dont have the room to get the punch at the vertex properly, it will also help to do this from the 'top side' of the nut, but the angle of force is not as favorable.

That should help, although it will leave some dents in the nut. If that doesnt work, then if you can get another nut you can simply cut it off with a Dremel in about 10 minutes, with one of those larger cut off disks (not the small flimsy ones). Those disks can cut through steel pretty quick. If you dont cut all the way through you wont hit the threads, and then you can break it off with some other tool like a chisel. Sometimes once the nut has a deep cut in one of the hex sides, the nut loosens (less steel left to flex) and it can be removed easily in the normal manner with a wrench, although it still has to be replaced.

Of course you have to have the room to work to use these ideas, so hopefully you do have that.

Good luck with it

Post by **E Showell** » 28 Jun 2015, 04:06

I'm on jack stands about 15" from the ground so I don't have a lot of room to get fancy.

Post by **abscate** » 28 Jun 2015, 05:18

Changed my mind. Dremel it off per Mr Al. You know you will save the stud if you do this. At some point, the bolt can fuse to that stud to the point where it just won't release in torque before exceeding the shear strength of the stud. 17 years in salt water and muck in the NE will do that.

A dremel tool is incomplete without safety glasses

Post by **cn90** » 28 Jun 2015, 20:29

I HAD the exact same problem with the 18-mm nut.

Had to use Propane Torch for 1 whole minute!!!
Even so, it was so tight that I thought I broke the stud, luckily the nut came out OK.
On re-installation, I applied antiseize, although I have to say that it is extremely unlikely I ever will go back there (don't plan to keep this car another 100K).

I like the dremel idea, just get a new nut, then dremel the old nut.

Post by **erikv11** » 28 Jun 2015, 21:16

I have a nut splitter, have used on front suspension nuts before, it is a really great tool.

Post by **E Showell** » 29 Jun 2015, 04:26

I just remembered that I actually own a nut splitter, although I have never used it before (and I already have a new nut since I bought new hardware before I started the job).

Post by **abscate** » 29 Jun 2015, 05:03

Make sure you split the whole width or else it is most dissatisfying.

I am convinced the Dr Dremel is a cult leader and I am a happy follower.