m.o.t.
 

hi all
another pass on m.o.t. volvo 940 tdi auto 1995 only had one failure in 18 years the garage said to much bounce in rear suspension i have nivomatt self levelling
told the garage these dampers are a bit more spring went to quick fit for a second opinion they said they woud pass them no leaks so back to garage and they passed car they were after work im sure we get to know these cars over the years .

Congrats Jim! Had the car sat for a while before going into the MoT ramp? If so the Nivos would "settle" and the back end would sag a bit until driven again - if they did the "bounce test" then they would respond with a lot of bounce until driven a while.

Was the MoT tester quite young? If so there's a lot of youngsters haven't heard of Boge Nivomats - i'm sure others will echo the ideas i've said above in terms of the behaviour and if further proof were needed, it says something along those lines in the Volvo handbook as well!

I'd agree with you, they were trying to look for work! Crafty gits! ;) :D

Are the nivomats any use?
Every car ive ever owned with self levelling suspension has never worked, MK1 Subaru Foresters, they never worked and cost a kings ransomn to replace. Also had countless Range Rover classics that had a boge strut on rear suspension, all it did was make axle ball joint a pita to replace. Suspension was no differant if it was connected or not, total waste of time!

Opinion varies on the Nivos Ted - i ran SD1 V8s for many years and Nivos were standard fit on those, at least the series one cars.

Some had been converted to standard shocks and springs (from the 2300/2600 usually, Nivos were optional on the 2600 for most of the early cars) and on my last V8, some kind soul had renewed the Nivos shortly before i bought it so they did actually work as shock absorbers - no good on the self-leveling though!

When i got my current 760, the back end was as wallowy as a pregnant elephant on roller skates. Eventually after a few miles of fen road driving, they firmed up and gave a passing (but not passable) impression of shock absorbers.

It was like traveling in the Herald of Free Enterprise most of the time and although they weren't leaking enough to fail the MoT (just a slight mist on each) i changed them for standard shocks and springs (new ones, ebay bargains) and it improved the ride considerably, raising the back end by about 30mm.
Odd that figure comes up - in the Volvo handbook it explains the action of the Nivos and says after loading luggage, drive for a minimum of 1.5 miles (i think, a while since i read it but the gist is right) and the ride height will return to within 30mm of normal.
To me, that isn't self-leveling - it should return all the way to normal.

In short, they're over-hyped, over-priced junk that don't work even when new IMHO except as shock absorbers with a slightly smoother ride.

I'm sure there will be plenty of opinions saying they're the greatest thing since sliced bread, just not in my experience. ;) :D

Nivos? God's gift!
 

Frankly Nivos working correctly are the absolute mutt's nuts. Nothing else comes close to what they give you. They also last about 110k miles which is nearly four times your average craaap. They have precisely 2 problems - (1) the price (but ten they are wonderful and last ages) and (2) you can't get them any more and apparently nobody can recondition them.

Even when Nivos work properly, they still don't self-level :

Land Rover developed a self-levelling rear suspension using the "Boge Hydromat" self-energising hydraulic strut.[13]

Of similar construction to a hydraulic shock absorber the strut used the motion of the suspension travelling over bumps to pump itself back up to a pre-set height. It was sufficiently powerful to regain up to 85% of normal ride height with a full load over the rear axle, and had the advantage of requiring no external power source or a dedicated hydraulic system in the vehicle.

That is extracted from this :

https://en.wikipedia.org/wiki/Self-levelling_suspension

My point is that the Nivos only get to a certain level, they don't actually return the ride height to normal. To me, that isn't self-leveling suspension and isn't worth the extra money.

I'd rather spend £20 on a pair of those "Rubber Donuts" better known as Grayston Coil Spring Assisters :

https://www.ebay.co.uk/itm/Grayston-...UAAOSwJH1ZKXwx

Each to their own! I'm just glad they've stopped making Nivos and nobody can repair them - there are better options these days that are probably nearly as cheap as Nivos and will get the ride height where it should be such as air-bags (not those IEDs built into the steering wheel, dash etc) and so on.

And the rest. I’ve got one 940 on 200k that still handles very well on its original nivos and another on 250k that could admittedly benefit from replacements but still passes the MOT.

As a aside to MOT testing , bounce testing of shocks is NOT allowed or prescribed in testmanual

https://www.mot-testing.service.gov....4s02000701.htm

See a tester doing so , ask them to produce the manual & explain where it says bounce the car

940 tdi auto 1995
 

hi all thanks for your comments . i too think the bouncing test is a bit of a chancer job may be im wrong

A bounce on the corners is a wholly inappropriate 'test' for Nivos whatever the case. It just doesn't work for these self-levelers.

All in accordance with Volvo procedures and measurements. Measure the backend of the car on even ground. Go for a little motor, and then measure again. Then check within measurement limits set out by Volvo.