Hey guys my dad owns a 1991 940 Turbo Sedan which he loves very much but last year he got the rear shocks replaced cause he said that they made a clunking noise and little did we know that the car came with special shocks from the factory (Nivomats) and he replaced them with conventional shocks and now a year later the rear is sagging pretty bad, it bottoms out almost every time especially when the tank is full. The car sits ugly and is very noticeable to anyone who looks at it and the axle is pushed towards the right by the pan hard bar so the axle and wheels aren't centered. Any ideas how to get it's rear to go up again? Also, will these overload springs work on his car? Overload Springs - 740/940 Wagon Models thanks.

 

don't use wagon springs on a sedan, they are too heavy duty, will harsh your ride.. you don't want overload springs either, for the same reason unless you ALWAYS drive with a FULL heavy load in the trunk... Just get standard sedan springs.

try these, Volvo Coil Spring Rear Sedans (740 760 940) - Pro Parts Sweden 30.6611 | FCP Euro

 

p.s. replacing the springs on a 7/9 live axle is pretty easy. get the rear of the car up on jack stands as high as you can stably.

put a bottle jack under the rear swing arm on one side, lift it just enough to take the weight off the end of the shock. unbolt the shock lower.

drop the swing arm enough that the spring comes clear of the swing arm. you need to reach way up inside to the top of the spring with a long extension wrench and remove the bolt thats holding the spring in place. there's a couple big washer things in there too. unbolt old spring, set aside, bolt up new spring, torque it down nice and hard (look up torque specs somewhere), then raise the swing arm back up with the jack and reattach the shock, torque shock bolt on to spec..

repeat on other side.

all told, shouldn't taken an hour going slow and careful. don't even have to take the wheels off.

 

Does it matter that Nivomats were removed?

 

Thanks for the reply, won't the rear sag again if we put regular springs?

 

I guess the rear springs got a beating from taking all the rear end's weight when the Nivomats were removed, I see other 940s driving around with the same problem as well

 

You can't just replace Nivomats with standard shocks. IPD sells a conversion kit.

 

the nivomats came with an extra weak spring as the nivomat shock itself provided the rest of the spring force required.

that replacement spring I linked is a standard one for use with regular shocks.

 

The swap is child's play if it is a live axle car; the conversion kit is for the IRS cars. As I recall, on my 760, I had to reuse one of the Nivomat bushings on the replacement shocks. On the advice of Nick Bauer at FCP, I went back with wagon springs on the rear. Then, and now, I don't understand his logic for not recommending sedan springs. It didn't affect the ride imo but it sure made for a high water car. f I were to do it again, I would simply use sedan springs.

 

ah, understood thanks!

 

alright so sedan springs it is! thanks for your reply

 

there's also a few bushings in the rear suspension that can get sloppy.

a 740/940 rear end looks like...


at 200k miles, the back end of my wagon had a slight bit of side to side clunking, and the rear end was sagging a bit, in addition to the mushy shocks. I replaced bushings 13, 14 on the panhard rod, and 2 on the main control arm, when I put new shocks on my car. I probably should have replaced 33,36 on the thrust arms too.

by way of explanation... parts 18,19,22 are a isolated subframe that is mounted to the car frame via rubber bumpers 21, 24 and studs 23, 29. the thrust rods 31, 34 pivot on the bridge piece 22, the other end of the thrust rods have the big bushings 33, 36 that bolt to the rear axle next to the differential pumpkin, these thrust rods 'push' the car body along down the road, they also keep the rear axle from twisting under torque part 12 is the panhard rod, one end secured to the frame, and the other end secured to the rear axle, this prevents side to side sway.


for general reference, here's the rest of the rear suspension of a 7/9 live axle...



#7 is the nivomat, and you can tell its a nivomat because it has the bellows.

 

Thanks for your reply. Speaking of bushings, the car's rear end vibrates during acceleration from a stop all the time but when it gets to around 25 mph it goes away, any idea what causes the problem? I was thinking that a bushing somewhere around the rear axle is toast but don't know which one

 

vibration under acceleration is often due to a worn out drive shaft center bearing.... the driveshaft between the transmission and the differential is in two parts on these cars, and there's a bearing supporting the middle, this bearing is in a rubber donut bushing, and that in turn is held in place by a metal cage. the rubber donut gets hard, and/or the bearing itself seizes, makes all kinda evil noise.

 

alright thanks I'll check it out, yeah it makes a rumbling sound during acceleration