Very bouncy rear end

[Laird Scooby]

Originally Posted by nutco

Ive got the ingredients now, Do you mix it in a spray bottle and spray it on,

You can do but whatever you put it in, the bottle and spray mech need to be able to cope with acetone. Give it a good shake before each spraying as well.

I used an old brake/carb cleaner aerosol, fitted the brass part from a tyre valve in the base (drilled a 5mm hole and pushed it in then soldered it), removed the core and filled the can with ATF first then acetone from a 50ml syringe, refitted the valve core, shook it and pressurised to about 100-120psi. Given aerosols usually run at about 260psi, 120psi isn't a problem as long as your soldering is good!

Normal compressors run to about 100-120psi, even the little 12v jobbies for pumping tyres up run to about the same so you can get some reasonable pressure behind it.

Others have used an oil can similar to this but have had to change the seals to acetone resistant ones.



Whichever way you do it, make sure it's sealed after so the acetone can't evaporate off or you'll be left with ATF.

[Laird Scooby]

Originally Posted by nutco

I saw that but are your 740 parts the same as the 940 as the numbers are different

If your 940 has a live rear axle (solid in other words) then yes, they should be the same.

Which numbers are you referring to as being different?

*** EDIT ***

Same spring from a different seller with ALL fitments listed :

https://www.ebay.co.uk/itm/SUPLEX-38...YAAOSw~l1Z8L0C

The reason i linked to one that was only listed as fitting the 740 is pure coincidence because it was the best price i found for that part number.

[nutco]

I used an old brake/carb cleaner aerosol, fitted the brass part from a tyre valve in the base (drilled a 5mm hole and pushed it in then soldered it), removed the core and filled the can with ATF first then acetone from a 50ml syringe, refitted the valve core, shook it and pressurised to about 100-120

You could be onto a nice little side line there

[Laird Scooby]

Originally Posted by nutco

I used an old brake/carb cleaner aerosol, fitted the brass part from a tyre valve in the base (drilled a 5mm hole and pushed it in then soldered it), removed the core and filled the can with ATF first then acetone from a 50ml syringe, refitted the valve core, shook it and pressurised to about 100-120

You could be onto a nice little side line there

I wish!

[nutco]

Originally Posted by Laird Scooby

Any "new for old" replacement springs will naturally seem firmer. However when i did mine i was so impressed by the improvement in the way the rear end behaved, i also bought new front springs and shocks and that improved it further- probably as close to how a new 760 would ride, except for the fact it's no longer on Nivos.

These are the springs i used :

https://www.ebay.co.uk/itm/Fit-with-...item4d402401e5

You'll need 2 of them and here are the shocks :

https://www.ebay.co.uk/itm/2x-Shock-...item361d09066c

That's a listing for a pair so for a total of about £91 delivered you can re-spring and re-shock your rear end and stop it bouncing.

If you're halfway handy with a socket set/spanners and have a trolley jack and axle stands, you can do it yourself fairly quickly.

The big thing i noticed wasn't so much a firmer ride but a much smoother ride - no more "seesaw" motion leading to sea-sick feeling!

Have just tried to. Buy the dampers but they are saying they will not fit my 940, were these the ones you fitted and were they ok, I have ordered the springs and want to make sure my set up is as good as yours laird scooby

[Laird Scooby]

That's a puzzle but i tried the ebay compatibility thing and according to that they don't fit yours - they don't fit mine either but they are on there doing a great job!

I had similar arguments with suppliers about other parts i found "That won't fit your car" so asked them to send me details of what they thought would fit.

There was no way on earth the part they thought would fit would have gone near my car. In the end with some parts i had to say to the supplier "Just send the parts i've ordered please and i'll pay return postage if they're wrong". I haven't had to send back anything as yet.

I've just put the details of my previous 740 through and it comes up ok with that, knowing the bodyshell on the 740 and 760 estates were the same and i'm 99% certain the later 940 estates will be the same if you have a live axle (solid beam, no separate halfshafts) so should be right.

Maybe Dai or someone else that's owned both 7xx and 9xx cars can double-confirm but i suspect the seller is trying to sell something a lot dearer - had that happen with a lot of parts for mine as well!

[classicswede]

Solid axle parts are all interchangeable between the 700 series and 900 series with solid rear axle.

[Laird Scooby]

Thanks Dai, i was sure that was the case but knowing Volvo can change specifications without warning and faster than they change the elk litter trays thought it wise to ask for a second opinion.

[nutco]

[QUOTE=Laird Scooby;2400778]

These are the springs i used :

https://www.ebay.co.uk/itm/Fit-with-...item4d402401e5

You'll need 2 of them and here are the shocks :

https://www.ebay.co.uk/itm/2x-Shock-...item361d09066c

Just an update, well i changed the springs and shocks for the ones the Laird Scooby had used (above) and bingo the ride is bang on, sits lovely and a great smooth ride, when I had removed the old parts I found that the springs were fine, both took a 25kg bag of spuds well only compressing a 1/4", so into the spares draw they go. 1 of the nivomats took a lot to compress and instantly returned when released, so all good there, the other one had no compression and stayed closed when pushed together, so thats what was causing my bouncily rear end, one note for anyone doing this job is too order 2 new studs and nuts that hold the top of the springs to the car, my studs were that corroded that the studs came out of the car body and the rubber doughnut expanded and it was a nightmare to try and compress the doughnut and put the stud back into the body in the middle of the spring, I tried every kind of crude remover even Laird Scoobys mixture but the nut was not coming off that stud, hope this helps someone

[Laird Scooby]

Glad the springs and shocks did as they were told!

Not sure about keeping the old springs though, you'll need Nivos to use them as they are longer and softer than "normal" springs.

Also consider that compression - 1/4" with 25kg on top. In theory a Volvo has about 370kg per corner (1480kg total) although more of that weight is on the front to start with.
Make the maths easy and call it 375kg which is 15 times 25kg so 15 times 1/4" is 3 3/4". Every 100kg in the back is going to drop it another inch.