Rear Beam Probably A Stupid Question

[pip470 61]

Ok i have rebuilt my rear beam no problems but my question is What stops the trailing arms from coming out of the axle tube other than what i can see is the shock absorber nut and bolts and the little stud and nut attatched through the torsion bars. I know the shock absorber bolts are substantial but is that really it? Im sure im missing something. Cheers phill

[welshpug 1,627]

just them bolts on the end of the torsion bars, and the ARB as well.

[pip470 61]

I considered the anti rol bar but the end plate is bolted on to the trailing arm once you push the plate onto the anti roll bar but nothing holds the plate to the roll bar, its just blanked off with a plastick bung. So really i dont think this would stop the trailing arm from being pulled out of the axle if you see what i mean, what you think

[welshpug 1,627]

yeah, forgot about that!!

 

it works though!!

[Guest ep82chris]

ive often thought the same thing but as welshpug said it works lol

[Guest smokinslim]

If you want extra assurance, get 2 bolts the same as those that hold the end plates to the trailing arms. Remove the plastic lugs from the end plates, and screw the bolts into the ends of the arb. They're a perfect fit and will make sure the end plates don't come off the arb (not that its likely anyway).

[pug_ham 242 3 Cars]

The ARB end plate is bolted to the radius arm which is held in place by the shock absorber lower bolt & the other bolts at each end of the torsion bar.

 

I've never heard of one failing in the history of the 205.

 

Graham.

[Jrod 7]

Funny this come up as I thought about this the other day when I adjusted my ride height.

 

The arms just slid out so easliy i was like.

 

[jonnie205 1]

Yes basiaclly it is only one m8 stud and the friction of the arb splines that holds the whole arm on. OK the damper lower bolt is in but that would not keep the arem on the ra should the m8 stud braak or nut come off, however it does seem to work

[pug_ham 242 3 Cars]

Funny this come up as I thought about this the other day when I adjusted my ride height.

 

The arms just slid out so easliy i was like.

Thats probably because Sam rebuilt the beam fairly recently when he had the car & probably took it apart to adjust the ride height a couple of times since he did it.

 

Or wasn't there a nut on the end of the M8 stud.

 

The 405 is far worse as the torsion bars are only held into the beam tube by friction & don't have the stud.

 

Graham.

[Rippthrough 98]

Dampers wouldn't hold it in as they're on flexible bushes at either end.

[pip470 61]

I was kind of hoping I had missed something really silly and say of coarse but im afraid there really is nothing substantial holding them together. But as graham has said and the fact that there nearly a classic and never heard of one coming apart on the road it does work. Who would of thought it. Thanks everyone

[pug_ham 242 3 Cars]

Dampers wouldn't hold it in as they're on flexible bushes at either end.

Maybe, maybe not.

 

Top mount is fixed between two plates so that can't come out & the lower has a plate the brake pipe flexi mounts to & tbh it'd take a lot of force to pull the bush out once the washer & nut are fastened on.

 

Graham.

[KRISKARRERA 2 1 Cars]

The 405 is far worse as the torsion bars are only held into the beam tube by friction & don't have the stud.

 

Graham.

So in effect if you take out the torsion bar and anti roll bar the trailing arm could potentially just drop out?!

[taylorspug 7]

Some lower model 205s and 309s dont even have an ARB, so there it is purely the shock mount and the M8 torsion bar bolt holding it all together.

[pug_ham 242 3 Cars]

So in effect if you take out the torsion bar and anti roll bar the trailing arm could potentially just drop out?!

Yes, it should pull out of the beam tube easily unless its seized in.

Some lower model 205s and 309s dont even have an ARB, so there it is purely the shock mount and the M8 torsion bar bolt holding it all together

Indeed it is, still I've never heard of one coming apart though.

 

Graham.

[Rippthrough 98]

The force on them is twisting rather than outwards though, hence the bearings getting mullered.

[pip470 61]

When your going round a corner though or worse if you lose the back end can you imagine the side ways forces that are acting probably more so on the wheel that is being pulled side ways in effect the way you would pull the shafts out of the beam. If i was on the design team i would of swore they would of come out. Just as well im not a designer.