CQ/S2 top mounts.

[John.]

Can anyone tell me if the strut top mounts for a B3(7A)CQ are the same as for a 95MY S2 avant?
I have spares for my CQ which I was going to fit to the avant but it seems they're different? Checked a car parts website and they list the SAME mount for both cars?

Incidentally the mounts I have are Sachs, part no. 802 446 (009)

Anyone?

[Error404]

Yes front mounts are the same

[John.]

Muchos gracias.

I'm thinking they're maybe so knackered that they look so different??

[Error404]

often the case. The blue and green OEM ones are different heights too.

[mcandmar]

From memory they were different, but i think the greens are all you can get these days. Difference was only about 4-5mm in height when new.

[John.]

Difference was only about 4-5mm in height when new.

Expecting it to sit a bawhair higher but I can live with that.

Below is the N/S on the old mounting.


And below is the N/S after new mounting fitted.


Also replaced the suspension arms and track-rod-ends.......and new adjuster rods also

Just need to nip-up the susp arm bolts with the weight of the car on them and then it's off to get the wheel alignment adjusted.
Heading north in the car in a few weeks time so should have it spot on by then.

[Lago Blue]

Perhaps what is best needed is a quick review...

John,

For yourself and anyone else who might be interested in what should be well known about these, a short review.

To your original question, McAndmar is correct, originally a '95 car would have come with a top-mount upgraded from what originally came on one from 1990. Those two mounts, although physically interchangeable and visually near identical, bore different Audi P/N's, but most importantly, are of different load capacities. They are not "the same". Explanation to follow.

When sourcing replacement top-mounts, it may be worthwhile to consider, despite that yes, un-aided there will always certainly be pot-holes out there severe enough that will totally fail even the best OEM mount on the first pass, it is IMHO never a good idea to use other than:

"Thee" top top-mount, which is the Boge mount with P/N 8A0 412 355A molded into its rubber body, but usually dealer ordered under P/N 8A0 412 323D because in part as follows:

a) The above V6 OEM Boge mount reduces significantly the number of immediate threats and short of that, is more durable longer-term over all other OEM style mounts regardless of manufacturer, as was independently tested by one Mance Etheredge (Mr. Pro-Mounts) years ago;

b) Although there are many physically interchangeable versions, colours (and all manner of heights) of this mount going back several generations of cars, all of which where built for applications that were -not- nearly as heavy as the last V6 cars, nor where they even Audis. Certainly they go as far back as a 1982 VW Santana; and

c) Once these items are replaced, a good deal of time and cost consuming re-assembly, perhaps alignment work is laid on top of (note also tire wear and even driving enjoyment are in part dependent on) them, work that best needs being preserved for as long as possible;

d) Therefore, however tempting it may be to assume a lower-priced visually similar replacement part may be sufficient, by sourcing the V6 recommended part strictly through the Audi dealer, one benefits from getting the latest/greatest/strongest OEM mount possible, which is backwards compatible with the earlier cars, while the reverse is not really true. Know that the earlier ones where superseded precisely because they were weaker, offer less protection and in use will collapse and fail faster, altering that alignment and so on. Weigh all that against any perceived more immediate cost savings of a less capable part. So just know that going in;

e) Use of any other mount, other than the the one with the above "molded in" Audi P/N, and/or trying to cross-reference to other brands or even other earlier Boge items simply may not be worthwhile as that is going to give you a weaker fix that fails faster.

To conclude, with the above in mind, that latest V6 mount may despite price, be the most cost-effective; and anything else more likely false economy.

[Vorsprung durch Technik]

Excellent information there Lago Blue and must go some way to explain why i haven't had to change mine in the 16 years i have travelled 65k combined miles in the 2 V6 avants. Do you know if the part numbers are different for lower wishbone bushes for the V6 cars compared to the 4 and 5 cylinder cars? One other question do you know the weight difference between the 20v turbo engine and the V6? Many thanks.

[John.]

Thanks for the above, good info.

I'll not be taking them back off !!

Will see how I get on.

[macspring]

Thanks for sharing.

https://store.034motorsport.com/stru...sity-line.html

Not sure if this is any good. Others may be able to answer if it is, thereby adding to this thread.

[Error404]

Nope ***** and don't fit

[jade]

Thanks for sharing.

https://store.034motorsport.com/stru...sity-line.html

Not sure if this is any good. Others may be able to answer if it is, thereby adding to this thread.

You take your chances with 034.... products do not live up to the hype and customer services Sucks, Better of going else where

[Lago Blue]

Pennies for your thoughts...

Vorsprung,

I will try answer your questions in detail later on. If your mounts are not "done", that may be some sort of long service record! You may already know how to gauge "done-ness" (and why it matters). For those who don't, I'll speak to done-ness now (and "why bother" in a further post), simply grab a handful of various sized coins and proceed as follows (this is Mance's tried & true method and whose many writings I humbly re-cap here).

This list is mostly for the front axle, for the rears where required, alter the technique but follow these general principals:

a) Home Position:
While safely parked, on reasonably flat ground, with wheels straight ahead;
b) Bare Tops:
Mount-tops (the cad-plated dished-washer above the fender turret) exposed, remove any plastic (if still present) or rubber (rears only) outer ring ;
c) Take a Stand:
Stand with feet as if they are wheel chocks, one in front and one behind a given wheel; so that you are facing across the width of the car, and look down at the dished-washer directly in front of you;
d) Point of Measure:
On the dished washer's circumference, at the point most inboard (i.e. at the washer's 12 o'clock, the point closest to the mount across the car, opposite your position, so on the far side of the mount nearest you, but closest to the car's centre-line, you will gauge the gap between the dished-washer's underside and the surface of the painted fender turret top. Old hands will know this is is the point of minimum clearance and why;
e) Mind the Gap:
Stack the coins such that they closely reflect the observed clearance at that most inboard point, then measure the stack height.

Stack Height Insights: Briefly, one purpose of the OEM cupped-washers is to serve as mount condition indicators for those who care to read them. Un-aided, mounts operate through 3 ranges of collapse, Break-in (they are settling and stiffening); In-Service (they remain at a near constant height); and Failure (they are weakened and and accelerating towards complete collapse. (Figures below are average (YEMV) for subject new dealer-sourced V6 Boge "355A'' mounts):

For pre-B4 chassis:
At install:

4mm-4.5mm

In the 200-300 mile range:

5-5.5mm

At 1,000 miles:

6mm

Notes:
For B4s, subtract 1.5mm, (V6 engine is much heavier but strut brace brackets decreases apparent gap height by 2.5mm)
For S-cars, subtract 2.5mm (car has the above brackets)

Mount failure begins:

8mm.

Complete failure:

8.5mm.

[Lago Blue]

Front Axle Weights & Control Arm P/Ns...

Vorsprung,

V6 Engine Weight:
I don't know what the V6 engine weighs, however the B4s carry approx. 2/3rds of their total tonnage on the front axle, which would be over 1000 lbs/ea. front wheel.

Forged A-arm Bushing P/Ns:
I'd be quite happy to be wrong on this one but no, I don't believe there exists but one large bush OEM P/N for all the models of arms which used the large bushes. The only outlier would be the few cars which had one of each, both a small and a large (O.D.) bush in each forged A-arm. Generally, the earlier cars had the stamped arms (but not always) and almost always smaller bushes but all can be up-graded to the latest forged arms/large bushes if you also mind to also swap to the late ball-joints. I have never read of any supercessions to these original offerings.

Possible Next Steps:
But your implied question is only logical. Renewing just the top-mounts while worthwhile, fixes only one-third of the strut's attachment points, so is really just a start to the repair. These sister joints to the top-mounts certainly could do with the same attention, for exactly the same kinds of reasons top-mounts ought to concern the discerning. With so much riding on the front end, how to best effect a truly world class yet real world hinge-joint here, as should befit a car otherwise of this calibre; is a question every enthusiast owner should know the answer to. However, because this is slightly off-topic and particularly as I have written ad nauseam on this subject, I will but point you towards this modest effort and welcome your response:

A Primer on “Stops” Mod, Bushing & A-arm Theory

[John.]

Lago Blue, are you related to Dr Spock?!(no offence meant by this)

That info you've given is very specific, how did you come by it?

Your link isn't working regards the arm bushes but if it's the one I'm thinking off is it relating to how the standard bush is actually very good in dampening shock and road noise compared to poly bush?