[xj40] Replacing rear crossmember (subframe) bushings on a 91 XJ40

As mentioned on a previous post I just did this procedure and it was highly
useful. The sound level in the interior has returned to normal and the car
handles better (the latter might be a subjective impression).

I received a lot of very useful, on target advice from fellow listers who
have done this job, and I thought I would pass along a couple of my own
observations to help others as well. It is not that big a job, or very
expensive. A couple of jacks (lifts) and basic tools will do it, although I
used air and power to make it easier.

I raised the rear of the car and put it on jackstands, and removed the road
wheels. I then supported the differential casing with a jack with a piece of
plywood to protect the crossmember. Although some listers commented they
didn’t think the diff needs to be supported, I think there are two good
reasons to do so, the first being that the diff will drop down considerably
with the crossmember removed, and a lot of stress will be put on the jurid-
probably enough to help a questionable one to fail. The other reason is that
it makes removing and replacing the crossmember easier- you don’t have to
use as much muscle power. A likely 3d reason, but I’m not absolutely sure
about this, is that the bolt right behind the bushing, which goes through a
diagonal brace, the crossmember supports, and the crossmember itself, and
through an aluminum spacer, will be difficult to remove with the weight of
the diff pulling the crossmember down. Providing you try to remove this one
last, which is logical because it is the least accessible. (No corrosion on
any fasteners on mine, I am happy to report, having lived in a town with a
salt mine eight miles away and heavy winters- everything rusted, rusted
quickly, and rusted badly.)

Removing the crossmember is straightforward and needs no comment. Removing
the bushings is something of a chore as they bond very strongly to the
crossmember. The bushing has three components, and outer cylindrical steel
shell, and an hourglass-shaped inner steel piece, bonded together with some
elastomer. I used a puller I made with a 4" PVC coupling and some half-inch
threaded rod to pull the inner steel piece out (it was loose enough to do
this - others have cut the rubber around it to remove it). I then used a
reciprocating saw (sawzall) to make a cut through the outer shell, and an
air chisel with a pointed tool on the corner of the cut to lift it up and
push it out. Went very quickly.

Putting in the new bushing was harder. Dave Lokensgard pointed out that
there is a TSB on using epoxy to hold in the bushing, but I have a feeling
(haven’t looked) that it applies to the old part (JLM1863), and not the
CCC6875 which supercedes it, and has a thick rubber coating on the outside
of the outer shell. I used the jury rigged puller I had made to insert the
new bushing, which worked, but it wasn’t easy. I had to scrupuously clean up
the interior of the crossmember before I could press the new bushing home.

Replacing the crossmember is pretty straightforward. I put the plywood pad
back on the jack, put the crossmember on it, and raised it back into place.
It helped to leave all the crossmember support fasteners loose until I
tightened the two bolts that go through the crossmember into the
differential casing, and go through two conical pieces on the crossmember
to locate the two precisely. Then tightening up the rest is easy. I used a
lot of thread locker, as did the makers, when I put it all back together,
and used the opportunity to power wash the wheel wells and surrounding bits.

Martin Violette
'91 Sovereign
Crozet, VA USA

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