Suspension questions (though not which not to fit!)

[jsr]

About 3000 miles ago, i had rose-jointed Avo dampers fitted, using the original springs. I have been happy with them, but ride quality seems to have deteriorated recently. There are a lot of speed bumps round my way which i'm sure is taking its toll! This morning, i noticed there was very little gap between the rear tyre and the top of the arch. There's not much in the boot, so i guess the springs are sagging/failing.

A search of past threads reveals linear 9" 375lb front and 300lb rear are a good choice for Avo's and will order some soon from the experts on here

The valving on the Avo's is hard and so harder springs should be used. Why is this as I would have thought softer springs would help keep ride quality acceptable? I'm not questionning whether it is correct, just want to understand it better!

I have Steve Heath's anti roller bar links, which i may not have setup correctly. Is it possible for incorrectly set up links to restrict the movement of the suspension? My car corners realy flat, but cant help think they are restricting the suspension soaking up small bumps. Will certainly check the setup and free them up if need be.

Finally, do i need any special tools to remove the shocks/springs? Does the spring need to be compressed in order to remove the shock?

Thanks for your help

[shpub]

The drop links do not affect ride height or the relationship of the wheel to the arch. That is a combination of the spring/shock and associated geometries and that is where to look first.

If the car is sagging, check the obvious things like a broken spring or suspension joint/bush. It could be that the springs have been compressed and are not as long as they once were and the ride height has dropped. Have the adjustable platforms been locked in place? If not it is possible for them to come loose and again lower the car.

[andy-w]

Best off with a coil spring compressor...easy enouh to do your own but easier with a brought tool...

I have got avo's on mine and have a gap of about 1" max between the top of the wheel and the bottom of the arch...dont think i can adjust the suspension any more to give it a higher ride height without losing that very very low look!!!!!

[the gazman]

You don't need a spring compressor with Avo but before you start replacing springs have a look at your ride height because AVO's are just a tad on the long side on the rear and as your springs settle you will start hitting the bumpstops if you ride too low.
I would measure the front of outrigger to the ground and then the rear and ensure that the rear is 10mm higher, I just did this on an Avo fitted car and it stopped all the banging and crashing.

[andy-w]

that might explain why i have got one of my rears nearly half way up the adjuster thread and it still rubs the arch every now and then...yes i know...i need to adjust it a little bit further but the opposite one is nowhere near as high up the thread???

[spend]

IIRC, there are little grub screws to lock the rings on avos, much easier to adjust if you have the correct C spanner. I think there was a thread some years ago about using larger or double bump stops? You dont need a spring compressor, just wind the platform adjuster off (you need to remove the damper tho).

I used to load my car up for touring (heavy boot full) and then adjust the ride height, thinking that when I arrived @ 1000miles away I would have to drop it down ~ surprise surprise the car was quite pleasant to drive, even tho it looked a bit like a dragster

Dave

Edited by spend on Wednesday 31st January 15:02

[andy-w]

instead of trimming the interior tonight i migh adjust the height again...i have got the damping rate set at about half way and that seems ok...

[GreenV8S]

andy-w said:

that might explain why i have got one of my rears nearly half way up the adjuster thread and it still rubs the arch every now and then...yes i know...i need to adjust it a little bit further but the opposite one is nowhere near as high up the thread???

There should be no need to set the left and right spring seats differently to each other unless you are compensating for some other problem such as a saggy/broken spring, bent chassis etc. If you find yourself doing this, it is better to look for the underlying problem. Trying to compensate for it by adjusting the spring seats is usually the wrong answer and can be positively dangerous in some circumstances.

[andy-w]

GreenV8S said:

There should be no need to set the left and right spring seats differently...

Thats what i thought, hence the question marks...i have made sure the wishbones move freely when the springs are off and they are not too bad...think i might just strip both side off this weekend clean and grease everything up and then have a look at the settings.

Of course my garage floor might not be 100% level either and i was trying to get the measurements from the top of the wheel to the arch roughly the same...i shall aim for level lower wishbones when i do it later and not worry too much how the body sits!!!

[spend]

Dont measure to the wheelarch just check it for clearance, measure ground to chassis. Bodywork is not a good reference point.

Dvae

[GreenV8S]

You need to measure the floor to ensure it's flat before you start. Slopes enough to throw you miles out aren't obvious to the naked eye. Mark out where the wheels are going to go, and stick a spirit level across between left and right front wheel contact patches and the same at the rear. It doesn't particularly matter if the front and rear are at the same height as long as both axles are flat.

[spend]

I've just made a very flat surface for my convenience if I find out my bloody ramps are'nt level I am going to be 1 unhappy bunny tho...

I use(d I hope) sand and wooden planks/ramps to establish a level, plank across so I can measure to chassis rails, and access to get under to adjust / measure. Of course if you have pits / 4poster its a bit easier

The home made plank / ramps cut from 8/10x2" are extremely useful... 2 = 4" which makes it a doddle to tweak ride height, get jack under... 4 = 8" which is nearly as easy working under car on stands.

Dave

I promise no more Blue Peter Tips today :-)

[the gazman]

spend said:

IIRC, there are little grub screws to lock the rings on avos, much easier to adjust if you have the correct C spanner. I think there was a thread some years ago about using larger or double bump stops? You dont need a spring compressor, just wind the platform adjuster off (you need to remove the damper tho).
I used to load my car up for touring (heavy boot full) and then adjust the ride height, thinking that when I arrived @ 1000miles away I would have to drop it down ~ surprise surprise the car was quite pleasant to drive, even tho it looked a bit like a dragster
Dave

Edited by spend on Wednesday 31st January 15:02

Good point on the grub screws in the spring seat and you can buy a C spanner from AVO direct at Northampton.
On the bumpstops, I really disagree with the idea of running double stops because you would be running on them at anything aproaching a slightly lower ride height than usual and be back to the banging and crashing.
I use the Powerflex progressive bumpstops and they are great but retro fitting them needs to be done with care, you would need to remove the top loop and that needs to be refitted with top quality thread lock as well as a locking nut.