Rusted, stubborn front shock retaining nut - 240

I have some *very old* shocks up front on my '85 245. I've finished all the
suspension work except for the front strut components. Over three different
work sessions, I've tried to loosen the retaining nut on one shock with no
luck. Well, actually, there's a little bad luck. As I've been yarding on
the bolt, one side has curled up. The gorilla in me wants to start using a
sawzall/hacksaw to cut away the shock in parts, but I know that won't work
(right?). I've been drenching the retaining nuts on both sides of the car
with penetrating solvent and that hasn't helped yet. Most of the bushings
in the car were a bear to remove because of the rust, so I'm concerned the
retaining nut is in the same class of stubborn. I've read in an older
thread that I can hit the area with a torch to loosen the nut. Before I go
out and melt my strut, I figured I'd see if somebody has any advice? Is a
propane torch hot enough or should I seek out a cutting torch I have a
tendency to break things, so I'm starting to think that I should probably
seek out a shop to remove the nut. But I'm also stubborn, and really just
want to do it myself, especially since this is the last of the suspension
mods and it's been a knock-down, drag out, bloody knuckle slugfest and I
don't want to quit in the 35th round.

Thanks in advance for any help or advice,
Mike

 

Which nut?

 

The cartridge retainer nut. In this case it's a large, thin, fragile,
rusted nut that would take an 2" wrench. I'm using large channel locks. A
good idea at the time, but probably not the best choice. The Billstein
replacement has the slotted-flange type retainer nut.

 

If the nut is accessible (sounds like it is) try this trick that has served
me so well over the years. Clamp a pair of vise-grips on the nut, as hard as
you can. This will elastically deform the nut so the threads are jammed, but
at right angles the threads are forced apart. Hit it with penetrant (I hope
you're using a real penetrating oil, and not WD-40) and give it a minute to
soak in. Repeat with every pair of faces on the nut you can access. Bet it
will come loose then.

Mike

 

Yes some times those are real tough. On the bright side, the ones for
the 700 series are usually worse. Heating them up is usually the best
way, and propane is not hot enough. Also, keep in mind that you
possibly have trapped oil and maybe even high pressure nitrogen, and
it'll want to expand as you heat it up - safety gear is the order of the
day. And large channel locks are usually the best tool - the correct
tool works great when the strut is brand new and they taking pictures
for the manual, but it fails miserably after the assembly has spent
years marinating in salt water.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

And what would you be knowing about salt water marinating, Mike?

 

Thanks, Mike. I guess it's some consolation that another model has it
worse, but I can't imagine it being any worse. That said, the thought of a
hot torch, trapped oil, high pressure nitrogen sounds like just the kind of
excitement I need in my life right now. Hopefully, I won't need the torch,
but in case I do, I'll be sure to don whatever protective gear I can find.

After I posted I started wondering if a monkey wrench might work as well?
Seem to recall using one for some large nut rusted to a pipe somewhere in
the distant past. The leverage was nice. Might even be able to borrow an
exceptionally large one, too Never knew just how tough an ocean
environment can be. It's brutal.

Mike

 

Wow, cool trick, Mike! Thanks for the advice. Will try this before the
monster monkey wrench.

Mike

 

There's a hook deal special tool that slips around the strut housing and
hooks through the sway bar eye. It's just 1/4" wire. It holds the strut
at the perfect angle so that you can twist the assembly to where the
caliper jams against the lower a-arm without starining the brake hose.
After you heat the strut housing thread area just cherry all the way
round, find a helper with another pair of channel locks or a pipe wrench
that can counterhold the housing and gorilla twist the nut out. I've had
a couple that still squawk on the way out even then. Get a good grip and
turn with a steady motion. If you get too anxious and atheletic you can
seriously bugger the threads on the strut housing. They are a very fine
thread pitch and can make starting the new nut unbelievably, tediously,
frustratingly difficult. You have to get the nut stared and run it all
the way in and out a few times with tapping and fiddling around the
thread area until you can remove the nut and start it easily by hand or
you'll never get it started with the insert in place. I generally use a
little never-seize on the threads going back in and pull thr nut tight.
If the car lives in heavy road salt areas I'll spray some under coat
around the joint before the boot goes back on. Makes the next
replacement much easier.

Bob

 

Generally the seizing due to rust is stronger than the small bit of
steel that's exposed in the top of the nut, so it doesn't matter what
tool you have on it. That's why the heat is necessary.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

As an addition - Volvo shock kits come without that nut, and you'll want
a new one. And they're incredibly expensive ($30+) from the Volvo
dealer. Most aftermarket shock kits come with that nut - keep that in
mind when you're pricing shocks
--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Your previous post was grim news. I was hoping more leverage would offset
the hold the rust had on the threads. Wishful thinking considering the
bushings were hell to remove - except the right trailing arm bushing. It
had been installed off by 90 degrees, so it was elliptical and just slid out
clean.

Been picking up one of the new springs and taking one of the new Bilstein's
out of the box every so often to just hold 'em and feel the love.
<sniffle>It's so bittersweet - they need a home. Checked the threads on the
shock a few times just to make sure I was turning the old nut in the right
direction. Glad you said something. Would have been bummed to have removed
the old setup only to find I couldn't put it together until I picked up a
new nut. Especially since I usually end up installing parts when most
stores are closed.

Mike

 

The Bilsteins that I bought came with a pair of retaining nuts to hold the
inserts into the housings plus a special tool for fitting them. These nuts
screw into the standard struts but are completely different shape to the
originals, as evidenced by the special tightening tool.

The reason for the different nuts is that the original struts are a solid bar
at the top, so the original nuts have a small diameter hole for that. The
Bilsteins are an "inverted" shock, so the top is a bigger diameter and the
retaining nuts have a seal that runs on the outside of the demper body.

Unless the Bilsteins you've got are totally different to the ones I've got,
you won't need the original nuts. Get the strut out of the car, pull the
spring off and hold the bottom of the strut very securely and you should be
able to remove the original nuts using stilsons. The goal is to remove the
nuts without damaging the strut tube.

I'd bought a proper "C spanner" to undo the original nuts on the struts before
I realised that I wouldn't need that $18 spanner or the original nuts with the
new struts. :-( It and a rubber mallet made getting the old nuts undone very
easy, though.

I also bought a set of deep offset ring spanners and got a mate to machine a
piece of hex bar to fit over the flats on the top of the strut rod (inside the
top bearing) before I realised that the Bilsteins use an allen key and the
aftermarket strut top bearings that I should have fitted eliminate the
recessed nut problem! I still have to change those top bearings...

At least the ring spanners are useful.

 

Cool post! Thanks, Bob. "Cherry red" is what I needed to hear. Figure
it's all hardened steel and I'm not going to mess it up, but I have a track
record of breaking the unbreakable. Been trying hard to contain my
enthusiasm, in the old days, my impatience would have gotten the better of
me by now. I sure don't want to mess up the threads on the strut housing
(or damage the brake lines or anything else in the neighborhood.) Keep
looking at the new nut that's going in to remind myself how fine they are
(and make sure I'm turning the right direction - caught myself turning the
tie-rod end locknut the wrong way for way too long recently - forgot it
wasn't attached to the tie-rod end. Now I frequently double and triple
check myself. Guess I'm practicing for senility.)

Will look for the hook deal special tool and see if I can enlist somebody to
help.

When I was in California, I never had to contend with rust. Now that I've
been in NY for some years, every nut is a knock-down, drag-out fight to
loosen. Been eye-opening.

I wrote most of this note before I ran out last night to work on the car.
Figured I had a couple of hours, so I'd change the seals on the fuel
injectors since they sound like they're leaking like sieves. Got set up,
sized the right tools, turned the nut holding the fuel line in place a
half-turn and the fuel line snapped. "Um, I'd like those 3 seconds back,
please?!" Forgot the penetrating oil. Guess I need some fuel lines...

Mike

 

Thanks for the info, Athol. I was looking at the strut last time thinking I
was going to have to replace both after I went after them with a sawzall.
At least if I have them out of the car, I probably won't slip and hit my
head again.

I was going to buy the special tools, but the shocks came before I started
the work so I compared the nut on the car versus the nut on the Bilstein.
They weren't even close so I figured I'd use the best tool available and
not worry about any small scratches that I put on them while installing.
Good thing you can use the ring spanners. Since I started working on
the Volvo I've pulled out a couple of specialty tools that I bought and
have carried around for 20+ years without ever using. Can't help but
laugh a little whenever one of them comes out.

When I asked the newsgroup, I figured I'd get a concensus answer. Instead,
I'm now armed with three different approaches to removing the nut. It's
coming off the next time I try, so I'm pretty excited. Bought a 15/16
box-end wrench and modified following the directions posted on Dave
Shannon's website, so it'll come in handy whenever I ever have to pull
the top nut.

Mike

 

Hi Just slit a piece of rubber hose down the side and place over the shaft
in case you slip with the jaws of the tool .After you tighten up the nut hit
the side of the tube with a punch so the nut doesn't undo .About a quarter
of an inch down from the top of the nut should do it .that way the thread
slightly distorts and locks , but will still allow you to remove the nut if
needed .

 

My Bilsteins came with an installation tool for their nuts. It is a piece
of gold passivated (coloured) zinc plated steel about 3mm thick. It is a
very neat fit around the nut, with two protrusions in the inside that lock
into the notches on the nut. On one side of the plate, there is a piece
sticking out with a 1/2" square hole to put the 1/2" drive ratchet and
then torque wrench into. IIRC, the plate is labelled Bilstein and has the
torque specification marked on it.

I was under the impression that this tool came with every pair of Bilsteins
for a Volvo...

If they are available, I'd seriously suggest replacing the top bearings
with aftermarket items. The Noltec ones I've got don't recess the top
nuts to anywhere near the same extent as the originals. I just need to
get around to changing them... Ditto for fitting the pair of whiteline
swaybars that are hanging on the shed wall!

 

Nooooooooooooooooooooooooooo.

If the nuts are tightened to the correct torque, they won't come loose.

If you do the above staking procedure to a Bilstein strut, you're also
risking distorting the bush and seal assembly that is integral to the nut.
If this happens, you'll score the outside of the outer tube of the damper,
stuffing it in very short order.

If you use the Bilstein installation tool and tighten to the torque
specified, they'll be fine.

For the record, I certify vehicle modifications for a living. If someone
came to me with a strut tube that had been hit with a punch, chisel, etc.
in the manner described above, they'd be sent away to get another strut.

 

That's so cool! But...this is the first I've heard of any tool shipping
with the shocks. I'm going to have to check the boxes, but I don't remember
seeing anything like what you describe. Guess I was on Santa's "Bad List"
again...damn!

Good advice. I didn't have too many choices regarding the bearings. The
rubber boot is dried and cracked and I've driven the car so hard, for so
long, on and off-road, that I thought a new set was essential. Can't
remember the brand I picked up, but I hope they have a similar configuration
to those you describe. Then again, might have more coal in the stocking
<shrug>. The bearings are in the box next to the shocks and springs.
Walked by them a lot last weekend, but since it was a social weekend,
wasn't able to work on the car...This weekend it just looks like rain, so
might have to wait even longer.

Thanks again and good luck with the bearings and sway bars. Dream about
making improvements to the engine, tranny and suspension (performance sure
is addictive), but until it's back to solid stock condition, have to
maintain some discipline.

Mike

 

In all seriousness, I'd suggest that you see if you can pick up a spare
pair of struts. If you were intending to do wheel bearings, shocks,
springs and top bearings, you could strip the spare struts down, do the
whole lot on them then change them over in one go. If you're changing the
ball joints and tie-rod ends at the same time, it's even easier. You
could have the pair of new struts assembled with all of those parts ready
to go. The changeover would involve disconnecting the brake lines,
taking off the calipers and discs, unbolting the ball joints (3 nuts per
side), screwing the tie-rod ends off and taking the strut top nuts off,
changing the struts over then reassembling, bleed brakes and wheel align.

Oh, the luxury of having spare cars lying in the yard. The '78
finally went for scrap last week but I still have the 2 '82s and the '88.