Two questions.

[ferret76]

Is it possible to replace the gearbox mounts without removing said gearbox?

Is it possible to change the steering rack gaiters without removing the steering rack?

Any advice greatly appreciated.

[David W.]

Yes, and Yes.
The steering gaiters will not be any fun.
Support the trans, and remove the 4 bolts holding the cross member.
David

[Fingolfin]

I imagine the gaiters can be removed by removing the tie-rod end after disconnecting the arm to the kingpin (on each side), and then sliding the old gaiters off (after removing the clips, if they are still there -- mine were gone). The new gaiters will give you trouble in sliding on, since you'll have so little hand room, but it's probably doable.

Gearbox mounts as David said.

[kennatt]

If you havn't a workshop guide then a brief explanation ,.....to do the gaitors you need a track rod end separator to remove it from the steering arm, you will see a lock nut up against the tre on the rod that comes from the rack the threads on these are handed ,can't remember which way left or right but if you look at the exposed threads on the rod you will see which way they need to turn to unlock. they will be tight and I have found that a largish stillson wrench is the best tool to just turn the nut a bit . then Undo the nut on the tre,use the splitter to separate the tre from the arm(You can sometimes do it using two hammers,one behind the tre and then hit the other side but if you havent done this before, then get a splitter) Once these two nuts are dealt with split the tre from the arm then unscrew the tre counting how many turns it takes for it to come off(You need to put it back on the same no of turms to keep the tracking.)Remove the old gaitor,and put the new one on they normally will spread over the locking nut if you are carefull,then reverse order. Good luck.

[chesney]

Also, using large cable ties is a better solution to using the original jubilee-style clips. Keep oil in just as well, but 10X easier to fit. Unless concourse of course, but I can't think anyone is going to judge you by your rack gaitor clips

[dp]

I may have misremembered what I did but can't you leave the track rod ends on the steering arm? I'm sure you can loosen the nut on the end of the steering rack that contacts the track rod end then there are a pair of flats on the end of the steering rack to spin it out of the TRE? If you mark everything you can even disasemble and re-assemble without putting the tracking out...

[kennatt]

yes probably the easiest way lateral thinking