ABY/ADU Cat joint Q?

[mcandmar]

Question for you all, does anybodys car have the spring loaded nuts/bolts where the Cats join the rest of the exhaust system, or just a straight nut and bolt?

The diagram below shows the two versions, plain bolts number 21A, and 21 for the spring loaded setup.

[s2_wot]

my s2 has the springs

hth

[Nuvo]

I think it's a combination of the two. i.e., 2x spring type and and 1x no spring type per cat.

edit: ADU uses 3 bolts without pressure springs. ETKA shows the ABY can use either type.

Personally, I think I would favour the use of the springs at these joints.

[s2_wot]

Mark,
Would a few photos of mine assist you in any way?

[mcandmar]

Only if they are handy Shane. I was taking the cats out today and got thinking about it as the CQ and S4 both have spring loaded joints after the cat but the Avant was straight nuts/bolts. Parts system only added to the mystery. It would make far more sense in my mind to have them spring loaded.

[s2_wot]

Agreed, they must provide at least some protection to the exhaust manifold in a speed ramp collision or similar.

I'll post a few pics for reference at some stage.

[macspring]

Agreed, springs for mine please!

[mcandmar]

Was thinking more about this and remembered i had a load of bits from the project engine i bought to put into the CQ. So had a dig through my nut/bolt collection and found a bunch of springs and spacers but no bolts. Then it dawned on me, maybe i bought some new bolts with all the bits from Vagparts many years ago. Not only that, i found a bag with a complete set of nuts, bolts, springs, washers, spacers, gasket rings, and gearbox hanger mounts

Anyhow, the spring clamps fit perfectly, stock exhaust system has larger holes in the mounting flange for the spacers to fit through, clamps it nice and tight with a bit of travel left in the spring, also lines the flange up nice and even all the way around. Jobs a good un

@David cant remember what way yours is setup, will stick my head under and have a look. Curious to see if the milltek system has larger holes for the spacer tubes to fit into.

[Nuvo]

It appears to be that if the cat require the 60mm sealing ring then you use the pressure springs, otherwise you use bolts without the springs.

[mcandmar]

Well that opens another can of worms. My parts system lists two o-rings, (4A0 253 137 A) for sping loaded connection, and (4A0 253 137 B) without. Both listed as 60mm.

I didnt fit the new o-rings so i guess i need to crawl under again and see if they are the same, and if not what the difference is