Cleaning up the Rear Beam

evilally · Post by **evilally** » 28 Sep 2010, 23:45

I've got the rear beam off the 405 and I'm busy getting it de-rusted and cleaned up. So far I've got all the brake pipes and brackets off, the roll bar off and the little bolts and washer thingies that hold the torsion bars in. Can anyone comment on how the torsion bars come out.....I was under the impression they should slide out once the washers that lock them have been removed. Do they slide a particular way? I've tried umm.....persuading them with a big hammer to no avail

Also, what the score with the rear hubs? BoL says if they are taken out you knacker the bearings and the whole assembly has to be replaced, is this true?

How much further can the thing be taken apart by Joe Average in his garage without special tools?

On the plus side, the bits I've cleaned with the angle grinder and wire brush attachment look like new

Post by **CitroJim** » 29 Sep 2010, 06:19

You were right first time Ally... A big hammer

The beam does get a bit rusty. Are you'll be replacing the trailing arm needle rollers then. Good idea to and also, whilst the beam is in bits, think about fitting grease nipples so that you can get lots of grease in there and maintain the bearings in excellent nick.

I've had 405 rear drums off in the past and reused the bearings no worries at all. Just be careful not to get them full of debris...

Generally, the drums can be a bit of a pain if the handbrake cables are a bit iffy and making the brakes drag. The drum will be very reluctant to come off, as it will be if there is a wear ridge on it.

A bit of percywatsit and a big puller usually does the trick.

Take care not to damage the grease seal on the hub. Often if the drum is a bit reluctant it comes off at an angle and damages the seal.
If it is, replace it. measure it and a replacement should be available from this mob.

evilally · Post by **evilally** » 29 Sep 2010, 13:10

Cheers Jim, I'll upgrade to a bigger hammer in that case

Needle rollers.....what/where are those

Drums are in bits and cylinders are off. Once I get the hubs off I should be able to get the drum back plates all cleaned up and painted.

New set of Sachs dampers to go on as well.

What would be required to do a disc and caliper conversion.....I really dislike drums

Post by **CitroJim** » 29 Sep 2010, 18:09

Hi Ally,

The needle roller bearings you'll find on the trailing arm shafts when you pull them out of the beam tube...

They wear badly due to inadequate grease and can collapse and in doing so damage the beam tube and the trailing arm shafts.

This is not perhaps the very best diagram but it shows the beam tube, the trailing arm shafts and the bearings along with the torsion bars. the red lines are suggested locations for grease nipples...

On my old 405 the hubs came off with the brake drums. You must have different ones I'm not familiar with if the hubs stay in place with the drums removed

As for a disc to drum conversion, not easy. You'll need the disc-specific stub axles and all the pressure regulating stuff that is specific to discs.

Believe me, it is not worth it. Drums are fine and actually give you a better and more trouble-free handbrake. Rear discs on most cars (except maybe hydraulic Citroens) are a complete and utter pain and best avoided like the plague. They don't work hard enough generally to maintain themselves in good condition and rear discs and handbrakes just don't go well together at all.

spider · Post by **spider** » 29 Sep 2010, 19:29

I'd agree 100% on not fitting rear discs, p.i.t.a to be honest if you do not need that much braking force.

Things such as seizing calipers etc, not very good handbrakes etc (think about it, nice hot disc brakes, apply handbrake, over an hour or two the discs cool down and retract a tiny fraction = less handbrake)

I too cannot remember about the rear drums on a 405, I do remember the estate has sensible shoe fittings (or was it the saloon) and the other has the horse-shoe retaining clips.

Jim, I think we are thinking of the 306 (and possibly ZX?) estates where the drum was just litterally the drum held on with a couple of torx screws (ie: the hub and bearings assembly stayed on the axle)

evilally · Post by **evilally** » 29 Sep 2010, 21:40

I'll be keeping the drums then. The only reason I fancied them was that I have discs on the Clio, and they've been pretty well maintenance free. I always seem to be fiddling with drums for one reason or another.

Here she is:

I've been trying all evening to get the torsion bar out. I've removed the bolt and the round retainer thingy at both ends. I've heated it, WD40'd it, hit it with a big hammer and tried a bearing puller on it. The bearing puller actually broke it was done up so tight

Am I being a plonker?

Is what I'm doing correct?

One day I'd like to finish this car and drive it somewhere........

Post by **myglaren** » 29 Sep 2010, 23:35

Have you tried soaking it with Plus Gas Mike?
An overnight treatment and a bit of percussive persuasion should break the grip so the puller can extract it.

evilally · Post by **evilally** » 30 Sep 2010, 22:15

Back with progress....of sorts

Ran out of Plus Gas so they've had a good soak in WD40. Was back out tonight heating and bashing for ages. At last, things seem to start moving:

Fantastic

......until I look at the other side:

....instead of the bar going through the other side, it's actually started to push the trailing arm off.

What should I do now? I started this with the intention of giving it a general clean and paint. My understanding was that removing the arms was not for DIY Joe, so I'm a bit worried. Should I try and bash it back on, or go the whole hog and bash it off?

addo · Post by **addo** » 30 Sep 2010, 22:46

I assumed you were going to do the trailing arm bearings.

Getting back to the spline thing - heat. I'd cook the arms (not the bar) pretty hard to see if the corrosion bond can be loosened that way. While smoking hot you could also spray more Rost-Off or similar in there.

Also a few good hits from the sides, to shock the splines free.

If hitting the bar end, look for a drift that's close to full diameter of the bar, and solid. Use it with the heaviest lumpy you can swing. Sharp, solid blows are what'll release it best.

evilally · Post by **evilally** » 07 Oct 2010, 21:40

Alright, took the first torsion bar off complete with trailing arm, then bashed the bar out of the arm:

....the bearings in the arm look perfect, no rust at all. Half tempted just to stick them back on, but think I'll just replace them. About £50 all in for both sides from the stealer.

The second bar put up a much bigger fight, I've been at it for 3 evenings but I got it at last

To anyone thinking of doing this, you need serious heat. I didn't want to invest in a full oxy acetylene setup, so I got one of these:

http://www.gasproducts.co.uk/acatalog/S ... Torch.html

Damn it's hot, gave one end a good heat and then the thing let go after 4 or 5 hard hits with a sledge hammer.

Also worth a look is this method, although it didn't work for me:

http://img452.imageshack.us/i/sandyspicrj0.jpg/

Tightening the nut up should pull the bar out without a lot of violence, worth trying first.

I haven't removed the last bar completely as I think I'll need to take note of where the trailing arm is in relation to the beam so I can set the ride height to what it should be on reassembly. Is this correct?

addo · Post by **addo** » 07 Oct 2010, 22:18

Bearing looks a bit dry to me - but then again you may have hosed out the tube with solvent, before that photo.

evilally · Post by **evilally** » 18 Oct 2010, 21:46

Hi guys, the time has come to get the bearings out of the trailing arms. Any suggestions on how to do this, bearing (harhar) in mind I don't have a press? I'm thinking it would save a lot of trouble to take the arms to an engineering shop and have them remove and refit them for me.

Post by **CitroJim** » 18 Oct 2010, 21:49

That might not be a bad idea Ally but they look excellent to me so just really heavily grease them and pop 'em back.

Any marks on the shafts at all as this is the give-away if they are worn. If the shafts are spotless, replacing them is not needed.

Well done there, you've done a tremendous job

I know exactly how difficult this job is.

evilally · Post by **evilally** » 18 Oct 2010, 22:06

That's good news, I'd love to just pop them back on as is. The shafts are very shiny

One thing about the caps that go over the outer bearing....I nicked one with the hammer taking the arm off, and as it was a little corroded there's now a hole in it

Are these easy to replace? Obviously I can't refit it as it would just let in mud and water and wreck the bearing. I hope I've explained that ok, if not I can post a picture.

addo · Post by **addo** » 18 Oct 2010, 22:43

Those pressed metal caps are usually just an internal slip fit. Lightly clean both sides and smear with neutral cure silicone or Permatex #3 if you're keen. Waterproof bearing grease will do if you're old school.