Legacy Rear Shock Bolts Won't Budge

[dirty_mech]

I've got a 2000 Subaru Legacy with some KYB Excel-G shock absorbers I'm trying to put on the rear axle.  After replacing the front struts, I figured the rear shocks would be a piece of cake.  WRONG.  The nut on the big bolt going through the lower eye hole of the shocks is as solid as any bolt I've ever had to crack. 

A local shop will do it for $150 but it's a point of pride for me to do it myself.  Plus I already shelled out $60 for the spring compressor tool.

I have not yet used a rattle gun or breaker bar on it yet because I'm trying to avoid removing the rear caliper, rotor, and backing plate which would be necessary to gain full access.  Instead I'm using a box wrench and a 5lb sledge to attack the nut.  100+ impacts and it will not budge.  I've tried soaking it in PB B'laster for 24 hours, with some extra right before an attempt.  I've also heated it up with a propane torch for a good 60 seconds.  No effect.

I see two options:

 

1)  Bust out the oxy-acetyline torch and get it glowing red before making another try.  The gas tank being nearby makes me a little nervous to try this, but I guess there's not much real risk involved if done right.

 

2)  Give up and remove the rotor components to allow for rattle gun and breaker bar attacks.

It's possible both approaches will be necessary.  Does anyone with experience have any suggestion on how to proceed?  Should I plan on having to replace the bolts?  All advice is much appreciated.

[lmdew]

They are a pain and it's hard to install them as well.  On installation you have to compress the strut with a jack to line up the bottom bolt hole.

 

Box wrench and a BFH to get the nut broke loose or a long breaker bar.

[msmithmmx]

Are the springs 18 years old? I suggest new springs. Get the misc. Other parts off eBay

[1 Lucky Texan]

60 secs of heat is quite a bit. I 'accidentally' discovered what has been explained on the Forums once or twice by the 'gurus' - after warming the nut with the torch, THEN (carefully) spray with PB Blaster or 50/50 ATF-acetone mix. As it cools, it will draw the penetrant in.

 

It was strut work that finally convinced me to buy an impact wrench. Wish I'd had it 35 years ago.

 

I know it sounds crazy but, try some force in the TIGHTEN direction, maybe a little back-forth on it will bust the rust!

[idosubaru]

Make sure to use 6 point gear, 12 point will strip the head.

 

Socket with long pipe or a breaker bar. Some need lots of leverage.

[dirty_mech]

Are the springs 18 years old? I suggest new springs. Get the misc. Other parts off eBay

Not off RockAuto?  I checked eBay but it doesn't seem very easy to sorth trough.

 

I see RockAuto, where I got the struts, has the whole assembly for a few bucks more.  codswallop.  It's a little late now.  Nothing is actually wrong with the rear suspension as far as I can tell; I just replaced the front for whatever reason and decided it made sense to replace the back ones too.

 

What's the deal with old springs?  Do they loose strength over time?

Edited November 19, 2017 by dirty_mech

[dirty_mech]

Make sure to use 6 point gear, 12 point will strip the head.

 

Socket with long pipe or a breaker bar. Some need lots of leverage.

Yeah I think I'm just going to have to bite the bullet and pull off the rotors to do a double breaker-bar method on it.  One on the back to prevent rotation, one on the front to break it.  I'll use solid 1/2" drives to do it.  Going to Harbor Freight soon so I'll pick up a pair to replace the one I have that's bent up like a macaroni elbow.

 

A fact I learned about breaker bars on the job; you can generate more torque by putting yourself between the ground and the bar and pushing up on them rather than pushing down or putting your weight on them.  An old mech taught me that one when I was having trouble cracking some wheel hub nuts.  Good stuff. 

[Fairtax4me]

Depends on how much you weigh and how much you can press. I find that a longer breaker bar makes things easier. And a 5 foot pipe.

 

I wouldn't replace the springs if they're not sagging or excessively rusty. Original Subaru springs will last longer than Cheapo replacements even if they are 18 years old.

[dirty_mech]

60 secs of heat is quite a bit. I 'accidentally' discovered what has been explained on the Forums once or twice by the 'gurus' - after warming the nut with the torch, THEN (carefully) spray with PB Blaster or 50/50 ATF-acetone mix. As it cools, it will draw the penetrant in.

 

It was strut work that finally convinced me to buy an impact wrench. Wish I'd had it 35 years ago.

 

I know it sounds crazy but, try some force in the TIGHTEN direction, maybe a little back-forth on it will bust the rust!

Thanks for the info!  I've never heard of the ATF-acetone penetrant; will try when I next get a chance.  For now I'll try using the B'laster after I've hit the nut with propane flame for 30 secs and then hammer it in both directions.  This will be my last attempt before removing the rotors for breaker bar access.

[DaveT]

Breaker bar with a pipe to lenthen the handle. Good to be sure that you are balanced so that if it suddenly let's go that you don't fall or slam your hand into something.

I weigh more than I can lift, at least in any position i could be half under a car, so pushing down works better for me. Sometimes I've found a way to use a leg to aid the pushing when the angles of my arm are lousy for mechanical advantage. But when I'm serios, I fire up the compressor and use the impact wrench.

[heartless]

old adage: "with enough leverage you can move mountains"

 

a good heavy duty breaker bar and a long pipe will give you adequate leverage to break the nut/bolt free... even a wimpy female like me can do this - with enough leverage

 

we have a 3/4 drive set for situations like this... and a length of black pipe large enough to fit over the handle.

Edited November 21, 2017 by heartless

[dp213]

Seafoam deep creep is the best penetrating oil I have ever used. It hasn't failed me yet. Spray it and let it sit for a while, that and a little heat should work. Oh, and a big breaker bar

[dirty_mech]

UPDATE:  I've got bad and good news. 

Bad:  I've made all my best attacks using the advice in this thread and was not able to get the bolt to move.  It appears it will be necessary to remove the rotors and backing plate to attack the bolt with a rattle gun and/or breaker bar.   The rear brakes appear to be the drum-in-rotor type for the parking brake too, so it will be a nice pain in the butt to disassemble everything.

 

Good:  The rear brakes appear to be around the 25% mark so I need to replace the brake pads anyway, and I might as well remove the rotors and replace the parking brake pads while I'm at it.  Those things probably haven't been replaced since the car was new.

Reading on this, I'm trying to decide if I should turn/replace the rotors or not as there appears to be no grooving.  I've read the back posts and am going to start a separate thread on this topic as none address it directly (or even indirectly very much).