Stuck Bolt in rear suspension

[forester2002s]

2002 Forester 5MT, 205,000km

 

I am trying to remove my Rear Differential, to fix it (I think that one of the output-shaft taper-roller bearings is worn - I have a rear-end rumble & about 1mm radial & axial play on the output-shaft at the diff).

 

But I am stuck on the first step of the procedure. I cannot get the suspension lateral-links (front & rear) disconnected.

 

I cannot remove the long outer lateral-link bolt (#20540AA000).  This has a 19mm hex head, and is about 150mm (6") long. I can remove the 19mm nut, and I can turn the actual bolt with difficulty, using lots of lubricant and a long breaker-bar. But the bolt will not move along its length to remove it. I've tried hammering on the loosened nut, but the bolt won't move.

 

How can I remove this bolt?

I'm reluctant to use heat, as this will destroy the rubber bushings. But maybe that doesn't matter, as it could be that a rubber bushing is seized onto the bolt any way.

 

Any advice for me? Thanks.

 

EDITED to add "a rear-end-rumble"

Edited April 11, 2014 by forester2002s

[Prwa101]

Hammer wd40 and pry bar. On the back side the bolt is exposed to weather and dirt and grime gets caught in the rubber. Give it some love haha

 

Prwa

[idosubaru]

i would do everything possible to avoid removing those lower lateral link bolts.  Unless I'm forgetting something they don't need to be removed to remove the rear diff.

 

Remove axles first, remove complete rear hub assembly with lateral linkage from underside of car...pretty sure there's a few options to avoid that bolt, it's the biggest debacle back there.

 

but yes - keep spraying, soaking, prying under the head, turning, etc to get it out.  heat if you have it.

[forester2002s]

Thank for the replies.

I would love not to have to remove the long outer lateral-link bolts, and take out the rear-diff that way.

Can that really be done? It seems to me that the output-shafts engage into the rear-diff by quite a bit.

I haven't tried prying out an output-shaft from the rear-diff, since I've assumed that it wouldn't work with the wheels in place.

 

I have been following the procedure in the FSM, which says that the lateral-links must be disconnected from the wheel, so that the wheels and output-shafts (rear-axles) can be pulled outwards freely, and be withdrawn from the diff.

 

And I've also found this write-up, which suggests the same thing:

http://www.scoobymods.com/showthread.php/diy-upgrading-replacing-rear-differential-14270.html?s=041abbabc731a0fd38f9148b3b5bc0ec&

 

Has anyone managed to get a rear-diff out, without messing with the rear-suspension?

 

By the way, the reason for wanting to work on my rear-diff, is a rumbling sound from the rear-end, and the subsequent finding of a loose output-shaft. I've edited my original post to add the 'rear-end rumble'.

Edited April 11, 2014 by forester2002s

[Rooster2]

I had a conversation with a friend last night. He had a similar problem with his Audi. He said no amount of PB Blaster, hammering, or cussing would remove his lateral link bolt. He couldn't use heat for fear of ruining rubber bushings. He finally got it out using an air powered impact driver. If you don't have one, I have had great success with an electrical impact driver that I bought at Harbor Freight for not much money.

[CNY_Dave]

I have an electric impact, used it to remove this SOB of a bolt on our '05 forester.

 

I used lots of real freeing oil (kroil, pb blaster is good, there are some others but WD40 is useless, ATF in a pinch, ATF + acetone is amazing), and I turned the nbolt by hand until the impact would move it a little, then I just left the impact on it and spun, spun, spun (outwards, of course).

 

If it is spinning, make sure to clean the exposed part so when it starts to come out it doesn't just jam on the thicker rusted part. When steel rusts it gets bigger (the outer rusted layer).

[forester2002s]

I have an electric impact, used it to remove this SOB of a bolt on our '05 forester.

 

I used lots of real freeing oil (kroil, pb blaster is good, there are some others but WD40 is useless, ATF in a pinch, ATF + acetone is amazing), and I turned the nbolt by hand until the impact would move it a little, then I just left the impact on it and spun, spun, spun (outwards, of course).

 

If it is spinning, make sure to clean the exposed part so when it starts to come out it doesn't just jam on the thicker rusted part. When steel rusts it gets bigger (the outer rusted layer).

 

Thanks for this tip.

Yes, I've been using WD40!

 

I'm going to try ATF + Acetone.

(ATF means Auto Trans Fluid, right?) What proportions would you suggest?

[MilesFox]

Turn it out with an impact whele levering it out with a pry bar. take some lesons from the folks in the rust belt. ATF is a good penetrating fluid and would work well by itself

Edited April 12, 2014 by MilesFox

[Fairtax4me]

Two things:

1: axial play at the axle cup on the diff does NOT suggest the carrier bearing is bad. The axles are not connected to, nor do they pass through, the carrier bearings.

Rumbling from the back is probably a bad wheel bearing, which is fairly common.

Worn bearings in the differential are not common. Its uncommon to have any problems at all from the rear diff.

 

2: You don't need to remove any of that to get the rear diff out. It's really much easier than the service manual makes it out to be. But, thoroughly check the wheel bearings first, because you probably don't need to remove the rear diff.

[MilesFox]

You should be able to pop out the axle by disconnecting the strut from the knuckle. It may be a tight fit, though.

 

But once you get the knuckle out, you can service the wheel bearing.

 

I caution you that if the bolt is that hard to remove, removing the entire rear subframe my break off some captive nuts, further complicating the job and causing excessive labor and down time.

[uniberp]

This isn't pretty, but it can be done. It's impossible to press out the bushing without a press. I cut the hardened bolt head off, it took a couple sawzall blades, found a washer big enough to brace against the rod, backed it up with an open end wrench, and pushed the bolt out with a ballljoint separator.

 

Impact wrenches and hammering are just absorbed by the rubber.

 

 

 

 

 

Edited April 13, 2014 by uniberp

[idosubaru]

+1 are you sure it's a rear diff issue?  that's almost unheard of.

+1 WD40 does nothing.  Use the stuff mentioned.

 

unbolt everything so the rear diff drops down with the axles still attached.  there's enough forward/backward left/right movement to disconnect the axles on 95-99 Legacy/outbacks.  cumbersome working under the car with all that weight hanging there but that's easy to deal with compared to that lateral link bolt.

[kanurys]

That bolt is the only reason I've chosen to not replace one of my bend lateral links. Someone put a jack on it before I owned the car, but the misalignment was correctable through an alignment.

 

I second the wheel bearing theory. That is much more likely to occur. Check the differential input and output seals. If there are bearing problems there will also be seal problems. Look for gear oil leaking.

[forester2002s]

UPDATING my original post:

 

Yes, I have moved away from suspecting that the rear diff is causing the
'rumble'.
 

I've been monitoring my rear wheel bearings.  I've jacked up the
wheels, and shaken them manually.  At first, I couldn't detect any
looseness. Then a few weeks later, I could detect a slight audible 'click',
very faint. Then I could detect very slight movement of the wheel, plus the
faint click.

 

That was on one of the rear wheels. Then a few days ago, I checked all of
wheel bearings, and discovered that one of the front wheel bearings is also
loose (that explains the occasional shimmy on the steering wheel at high
speeds).
 

I have loosened that long lateral-link-bolt on the rear, and managed to
remove it.
 

I am now looking for used hubs, one for the rear, and one for the
front.  None available locally - I am reluctant to order a used hub
online, without actually being able to see it first.
 

My local Subaru dealer wants $500 to replace each wheel bearing (they don't
do this on the car; they remove the hubs the old way and press the bearings out
and in).

 

My trusty local mechanic has just retired, so I am shopping around for
choices.
 

Meanwhile the rumble has got worse, but not by much. I think that I can
continue driving for quite a while, before the situation gets too serious. It's
just a little noisy.

[ivans imports]

Oh the rear wheel bearings on these cars what fun I bought a 1-1/2 drive snap on gun just for that bolt

[zombieforce]

Im doing one on my car right now at work. I take the links loose from the body to get the axle out and then I knock the hub out with a brass drift and hammer. After removi g the snap ring I pulled the beari g out with a long bolt piece of steel to fit the bearing and a nut against a steel cup. Then you just reverse the process and use the long bolt and nut to push in new beari g and hub.easy and saves the tedious process of messi g with the long link bolt.

[lmdew]

Swap to Disk Brakes.  I have everything you need $200 + shipping from CO 80919

[pontoontodd]

You can get new hubs from Rockauto for $10-20 each.

The wheel bearings can go for quite a while and just keep getting sloppier and noisier.  I've been told the car will become undriveable due to the slop before anything catastrophic happens, but I wouldn't push it.  You could try retorqueing the spindle nut, I've had them back off slightly even when staked.