Top Mount Saga continues

[Error404]

The shock shaft does ride on the bearing, as the bearing rides on the spring seat, which is seated on the shock shaft with a large nut retaining it.
There is nothing different in how the MKIV and B4 mounts work, the shock does not take direct loading on either set-up unless the shock bottoms out, in which case your shock and top mount are ****ed either way. In normal operating conditions, all of the axial load through the shock shaft is transferred from the spring, through the spring seat.

[rynaqui]

So what is the best option to go for right now? Getting a bit of knocking noise when turning the steering so thinking I'm due for my first set of top mounts, not bad for 5,000 miles on Maltese roads

[Monkeymagic]

When i get 5 mins ill let you know. I see no reason why they wont interchange especially as the kw spring plates are narrower.

[afterburner]

The shock shaft does ride on the bearing, as the bearing rides on the spring seat, which is seated on the shock shaft with a large nut retaining it.

I'm sorry, but still - you're not correct I don't want to insult you, but I have bearings and MK4 perches at home. I know how they work.

The shock goes through the bearing and fastens the bearing to the top mount, but only through the outer shell of the bearing, which does not rotate. The spring perch lies on the rotating part of the bearing, so technically it's the only thing supported by the bearing.

The spring perch is NOT seated on the shock shaft, it's only seated on the inner shell of the bearing. This means that the spring perch is not tightened or fastened in any way, it just contacts the bearing and relies on its shape to stay centered on the bearing.

In the image you've posted the side of the bearing facing you is the side that sits up when installed in a car. This is the shell of the bearing, it's the part that doesn't move and it's the part that interfaces both shock shaft and top mount. The part of the bearing that you don't see in the picture is the actual rotating face of the bearing and that's where the spring perch lies. It's the opposite of how an Audi bearing works. In the Mk4 golf when the car steers the shock shaft doesn't turn, the big shock nut doesn't turn, the cap that holds the whole strut from falling when the suspension is unloaded doesn't turn.

I'll take pictures of the parts that I have at home when I get there.

EDIT:


That's the MK4 bearing. The shock shaft goes through the bigger hole in the middle. Only the threaded part of the shaft protrudes through the smaller hole in the bearing (the outer shell). The spring perch and the spring perch alone contacts the "toothed" part of the bearing, which is the one that rotates and takes the beating.

[Vorsprung durch Technik]

This thread is hotting up and becoming more interesting as the days go by.The more i read, the more i realise that audi in one way are a bit of a joke.If they can't design a top mount that wont last more than 5-10k then it's crazy.Seams half baked to me...they produced the wonderful 5cyl design and quattro and Aluminium bodyshells.I did design and tech back in 83 O' LEVEL and it would seem their suspension engineers were not up to the task.Or was it they knew of the problem but just turned a blind eye.

Someone please come up with a solution that doesn't increase the height of the top mounts, is quiet, reasonably stiff yet gets rid of the inbuilt design flaw. I will buy you a beer or two

My post was being written while the other post was put up so no direct reference to the point in question raised.

[Monkeymagic]

This was my thoughts which is i asked which bearing to use. I have some vearings in my u nit so can trial it in my kws without any expense.

[Skull]

afterburner: So are you saying that on the mk4, the shock shaft is rotating inside the strut?

[afterburner]

afterburner: So are you saying that on the mk4, the shock shaft is rotating inside the strut?

Yes! Find a Golf MK4 (or another VAG vehicle using this design) and turn the steering wheel while looking at the top mounts. They don't turn like in the Audis The shaft stays stationary and the shock body rotates around it.

[Monkeymagic]

Yes the stanchion stays still the lowers rotate

[Error404]

Afterburner I stand corrected - I understand now what you are saying with reference to the assembly of the MKIV mount
I have been out to look at one in the work carpark

Regardless the bearing, via the spring and spring perch still takes all of the axial load of the sprung mass of the car on that corner.
The assembly itself is not going to make a difference to how the load is applied to the bearing - the load rating of the bearing and the design of the topmount housing is the "upgrade" over the B4 system.

[afterburner]

I'm happy that now we have an understanding!

I also understand your reasoning, but I think it's the dynamic loads that come from the shock that do the most harm (especially in my beautiful and crater/pothole filled motherland ), not the static ones that come from the spring, in an Audi top mount.

But I don't have the equipment nor the scientific degree to prove my theory, so I can't argue with you about it. Just giving the others my point of view

Cheers!

[Error404]

Likewise, I cannot give you numbers. We can agree though that the MKIV type mounts are much better than the B4

[Monkeymagic]

So which bearings to use then?. I would assume the mk4 ones but will turning the stanchion in the lower leg lead to more prooblems?

[Monkeymagic]

Ive ordered some powerflex black s3 ones and the retaining nut. Ill be a guinea pig...

[Error404]

oink oink