Volvo S40 Geometry

[rasputin]

2001 Volvo S40 1.9D with 145,000 miles.

 

I got this car 6 months ago and it always felt a bit odd when going over bumps or rough surfaces at higher speeds. It felt a bit wobbly at the back when I'd only expect it to go up/down, and it felt like it was fishtailing slightly when going over very shallow standing water.

 

It was in a local garage for a service yesterday and although I've had the suspension looked at a couple of times already, I asked them to have a look. I suspected the N/S/F strut top mount was worn. They said it wasn't worn, and that the suspension all looked fine, but - both rear tyres were worn smooth on the inner 2 inches. Nearly new (7.9mm tread) Goodyear Excellence - bugger!

 

Last time I checked the treads was 3 months ago and it was perfect - so whatever happened, was pretty quick. I did have new rear springs fitted recently so that may have caused an issue.

 

Anyway, this morning I had the tyres replaced and had a geometry done at a local place - unfortunately I don't know if they're any good or not. To be honest they didn't inspire much confidence that they knew what they're doing!

 

My steering wheel now points straight, which is nice... I went for a drive and it all feels better, if still not 100% (more "test driving" required I think).

 

Here is the report:

 

 

Any comments? Does it look like the job was done ok?

[Tony]

Sorry but it's no good..... The car has a bend on the NSR.... Probably one of the tie rods. Either way the rear cambers should be -40' +- 15', not -2d 58 and -1d 22.

[rasputin]

Thanks Tony.

 

I don't understand so much about this. For example looking at the Rear Left Camber. It says Initial -1d50'... Specifications -0d55' to -0d25'... Final -2d58'...

So that shows it's actually further out than before?

 

In that case Front camber on both sides, Rear camber on both sides and SAI on both sides is still out?

 

I can't get to a more reputable place for a while, so I'll try to keep the mileage down to preserve my new tyres... but is it worth trying to get a refund for the work done today?

[CIH]

SAI is only a couple of minutes beyond OEM so I personally wouldn't worry about that. Camber isn't too clever but IIRC isn't adjustable from the factory ? It probably moved when they adjusted Toe to spec.

-3 degrees Rear camber is much too deep but again I'd be surprised if it's adjustable.

 

Tony, do I read correctly the near-enough-even IA indicates an unsprung bend on the Near Side ? Haven't checked my notes for a while

[rasputin]

I'm pretty sure the Camber is adjustable on the S40. And if I understand the explanation on this website - it's the Camber that would cause severe wear on the inner couple of inches of the rear tyres - so they will wear again (even faster now on the N/S) if they're not fixed to spec?

 

As for even IA and unsprung bends - straight over my head!

 

I've had the rear suspension looked at by at least 3 different garages now and none saw any faults. I also had a look myself but I don't especially know what to look for. I tried again today - before finding out that this place has stripped my McGard key by using an impact wrench to do the nuts up...

[Tony]

Let's backtrack without over complicating things.....

 

The car "has" adjustable rear toe and camber so the OSR positions are consistent with an adjustable chassis that needs some adjustment (basically wrong but correctable).

 

 

The NSR's main issue was the toe at -44', which is huge.... to correct this the adjuster cam would have "maxed out" so they have also used the camber cam (sacrificial) to adjust the toe.... This was wrong!

 

Ready for some simple trigonometry?...... The camber adjuster would be near to the wheels centre and the toe "off-set" from the centre.... since the toe adjustment has violated the camber, the camber adjuster (arm/rod) whatever must be bent since it cannot lift the wheel back up.

 

Simply put if you look at the remaining problem then it's vertical... what part of the chassis is responsible for the vertical position?

 

@ caminhead... IA often violates OEM positions since there's no tolerance for coil sag...... Look for symmetry.

[rasputin]

Update on this...

 

I took the S40 to another place which seems to be highly recommended on other forums by Scottish members. It was clear the guy working on the car knew & cared a lot more than the garage in my original post. His first comment was that the N/S/R camber was visibly out. His second was that the last place fixed the toe by using the camber adjuster - because the toe adjusters looked untouched (and were siezed).

He also commented that something must be bent or there must be accident damage for the N/S/R camber to be so far out - but after a full investigation he found nothing wrong at the rear.

 

He managed to free up the toe adjusters with what looked like a lot of effort and cleaning/heat. And this is the result:

 

 

 

The O/S/R toe was flickering between 07' (green) and 06' (red), he just happened to print the page when it was red.

 

The N/S/F camber, he said he was reluctant to adjust it as it could mess up the other front angles, and it is not causing any uneven tyre wear as far as I can tell. I would guess this is out because the strut top mount on that side looks worn - although 3 separate garages have now told me it is either not worn, or not worn enough that it's worth replacing yet.

 

He seemed to put a lot of effort into getting things right, but said he couldn't get everything spot-on due to the age/mileage of most parts on the car. Seeing the difficulty he had with the (almost) siezed adjusters, I'm not surprised.

 

So... how does it look now? I notice the camber specs on his machine are different to the ones in the previous garage. Will my tyres be ok now?

[Tony]

Blimey she was hurt!!!...... All looks good now, yes you will get inner tyre wear but it may be at an acceptable rate.