306 Rear Arms On A 205 Beam

[pugpete1108 62 1 Cars]

i know people use gti6 rear arms for better camber etc on a rear 205 rear beam but seeing as im breaking my 306 cab i was wondering if they will go straight on? (obviously along with another rebuild)

 

im still running a hub beam and tbh its pretty cr*p and i think i may have amost stripped the thread on one of the bolt holes.

 

if they will how do i go about it? are the traiing shafts the same size as 205 ones and will the 205 arb fit the 306 arms? or is it a case of counting the slipnes and see.

 

cheers

[Anthony 1,000]

It's a straight swap, noting that you'll need to use the 306 disks rather than 205 ones.

 

205 torsion and anti-roll bars will fit straight in.

[welshpug 1,622]

yes it will fit straight on unless you have a VERY VERY early 205, use 205 torsion bars and arb, it will give you an extra 9mm or so track width so you may be able to ditch the spacers on the rear as its in the hubs not the trailing arm.

 

you will need to use 306/zx/xsara discs because of the extra offset in the hubs.

[Tom Fenton 1,525]

As above. Make sure you undo and remove the small bracket for the abs sensor wiring as it will foul the body on a 205. I usually chop the cast lug off as well as its no use to you on a 205.

[S@m 156]

Just out of interest, does anyone know if this effects camber aswell as track? I have a 306 s16 rear axle that i could liberate the arms from if its beneficial when i do my (inevitable) rear beam rebuild.

 

Sam

[Anthony 1,000]

0.5 degrees camber on a 205 arm, and 1.2 degrees on a 306 arm.

[S@m 156]

0.5 degrees camber on a 205 arm, and 1.2 degrees on a 306 arm.

Thanks for that Anthony - seems it is beneficial.

[pugpete1108 62 1 Cars]

cheers for some good news guys, deffo worth doing then.

 

the beam tube i think is originally from my 87 plate, is that too early?

 

will be using everything from the 306, disks callipers etc, just need to add another copper line as im running the 1.6 gti setup so only one line running to the back.

 

what can i use in the way of compensators? im pretty sure i chucked the 1.9 ones i had

[Tom Fenton 1,525]

I think 87 is after the changeover to the later type beam, but I am sure someone else can confirm.

 

Brake pipes wise you can leave it as it is with the single line to the rear that tees off to each side. Also leave the 1600 compensator in place, it will work OK with rear calipers and is much more reliable than the 1900 type.

[Anthony 1,000]

1987 will be fine. It's only very early Phase 1's that are the issue (circa 1984/85 AFAIK) and these are likely to be all but non-existant these days, given how few cars of that age are left and the likilyhood that many of them will have had replacement beams fitted at some point anyway.

 

As Tom says, leave the brake line layout and compensator as it is - you'll need to replace the lines from the beam flexis to the calipers (or use the 306 ones) and you'll need 205 1.9 GTi handbrake cables, but that's about it.

[pugpete1108 62 1 Cars]

cool cheers

[coulpug 0]

yes it will fit straight on unless you have a VERY VERY early 205, use 205 torsion bars and arb, it will give you an extra 9mm or so track width so you may be able to ditch the spacers on the rear as its in the hubs not the trailing arm.

 

you will need to use 306/zx/xsara discs because of the extra offset in the hubs.

 

so would that be about the same as installing a 309 beam for track width?

[welshpug 1,622]

a little less than a 309 beam, which would be better as you'll be less likely to rub on the arches.

[dave205 19]

I know this is bit of a thread highjack but will 306 arms fit a base model beam tube? What are the differences between a 1600 gti tube and a 1.1 tube?

 

Also what model 306 is the best to rob the trailing arms off?

[Baz 421]

Yes. No difference between tubes.

[dave205 19]

Cheers baz. I have a couple of base model beams here so will strip one when i get chance.

 

Do you know if the trailing arm shafts are the same aswell?

[Anthony 1,000]

Strictly speaking, base model and GTi tubes are different. They are however interchangeable, and you can use 306 etc trailing arms no problems

 

Replacement trailing arm shafts are the same, but you need to be a bit careful if you're using shafts fitted to base model beams from the factory, as some of them - notably some earlier ones without ARB's - are a different and some of them have a smaller inner diameter and hence an ARB won't fit.

 

To answer your next question, yes the bearings and seals are the same as those used on a GTi.

[dave205 19]

Ok thank you for that, i assume the best way to go about it is to strip the base model beam down and check it? Ive started stripping my gti beam down, so i should have a large pile of scrap by the end of the weekend

 

To pick your brains again anthony, which model of 306 do i need to get some arms off?

[pug_ham 240 3 Cars]

To pick your brains again anthony, which model of 306 do i need to get some arms off?

 

A quick look on autodata says every 306, drum or disc, has the same amount of rear toe & camber but the best bet would be to get a pair from a disc braked rear beam as these all share the same part number trailing arm on service box.

 

g

[welshpug 1,622]

Also bear in mind that the hub and disc on a 306 is taller, so may be an issue if its a base model shell, however does mean that deeper offset wheels can go on and still clear the trailing arm without spacers.

 

Difference is 9mm per side.

[dave205 19]

 

A quick look on autodata says every 306, drum or disc, has the same amount of rear toe & camber but the best bet would be to get a pair from a disc braked rear beam as these all share the same

part number trailing arm on service box.

 

g

I'll try and get hold of some gti-6 ones then. The only thing i was thinking i would be quite happy to retain drums on the back, as they seemed to work well with the 1.9 fromt brakes i was running. Would 205 1.6 items be transferable onto the 306 arms, or would it be easier to buy a lower model 306 like a 1.4 and use the drums already fitted?

[dave205 19]

Also bear in mind that the hub and disc on a 306 is taller, so may be an issue if its a base model shell, however does mean that deeper offset wheels can go on and still clear the trailing arm without spacers.

 

Difference is 9mm per side.

So to clarify, a 306 hub and disc is a bigger diameter? What difference will that make, as it is be fitted to a base model shell. Also i assume when you say 9mm you mean track width will be increased by 9mm each side? Allowing deeper offset wheels to be used?

[Anthony 1,000]

You can use a 306 drum arm just fine, although some of the 306 drums are a fair bit larger than the 205 ones, and you may or may not need to do something with regards compensators - I've only personally fitted some to a 1.6 which has a compensator in the engine bay, whereas base models had them as part of the wheel cylinder itself.

 

Otherwise, just swap the complete setup over from the 205 arm - I think you'll need to move the stub axle too as I have a feeling that the 205 and 306 drum ones are differing lengths.

 

The 306 disks are the same diameter (247mm), just a different offset and will bring the wheels further outwards, thus increasing rear track.

[Baz 421]

The 306 disks are the same diameter (247mm), just a different offset and will bring the wheels further outwards, thus increasing rear track.

 

Not exactly correct, the discs won't do anything for the rear track width as they're all the same thickness at the wheel mounting flange. The disc offset just depicts where they sit on the hub so they fit centrally in the caliper, it's the complete arms/hub assembly give the extra width.

[cybernck 400 1 Cars]

Or more precisely, It's just rear ABS-related stuff that ultimately causes the need for taller discs, as the caliper position remains the same.