Enclosed rear bar beams are used on cars under 1.7 litres. The larger engine cars used open type bars which I will cover in another article.
You need a bolt/stud (I use the gearbox - engine bolts as the threads right as is the length), a spacer (I used a 30mm halfords socket), a nut and a spanner.
A jack and 2 axle stands also make the job a lot easier.
Popping the caps off and scraping out any corrosion, or even better a wire brush attachment in a drill, and applying penetrating fluid a week or so before can help this job - sometimes.
If anyone says they can lower it by a spline which equals 30mm or they go it lowered 1 or 2 splines, basically call them an idiot and walk away, thats not how it works. They don't know what they are talking about so ignore them.
1 spline will generally drop the car by 80 - 120mm.
The torsion bar with the wheels off the ground and on axle stands are under tension, removing the bottom damper bolt removes this pre load and makes the job easier, its not vital if you do this but easier. The wheels won't swing down, it will drop maybe and inch with the damper bolt removed.
In this case I done the job on Project Y, I never removed the road wheels (I did on the nearside after a minute or so as it was being difficult) and I never removed the bottom damper bolt.
First remove this cap
if you see this then scrape it clean and if you have it get the drill and wire brush attachment in there.
then using your NASA spec torsion beam removal tool which is this
screw it into the tosion bar, don't tighten it right up into the bar though! You then tighten the nut which draws the bar out
halfway out
just a bit more
there we go!
As you can see its rusty, wire brush this off and clean it up and grease it. I will talk more of this later
If you want to lower the car an inch or so then if you removed it put the damper bolt back in, push the drum/disc down to the ground until the damper is at full extension, with some grease on the splines put the torsion bar in, if it doesn't go rotate and try again until it eventually slide in easily.
make sure its fully home like this.
Repeat on the other side and the car will have an equal drop.
If you want the car raised you need to remove the lower damper bolt and push the drum/disc down.
If you want to lower the car further raise it up slightly then shove the beam in.
This is the offside, I am in the process of removing the bar, it pulls right out
I then turn the bar around when its fully out, after cleaning the spline I re-insert it, I do this a few times to clean the splines in the bracket and the bar itself. It should slide easily in. When its clean and slides easily apply some grease to the splines
This is the bar fully removed
slide the bar in
make sure its fully home
The bar shoudl be able to slide in and out on a lowered set up easily, like this video shows, this it done with my fingers alone
YouTube - Enclosed Rear Torsion Bar
Open rear bars are basically the same except they are more exposed to the elements and can be more difficult.
This took me start to finish about 20 mins including pics. But I have done a lot of these in my time.