Does anyone know why the different color markings on 740/940 coil springs and what they mean?

 

I dunno about volvo springs specifically, but on other cars I've seen, colored dots have no real significance, they might be spring lot numbers or something that day in the factory, but they don't match up with part numbers or anything meaningful, so I doubt volvo's any more methodical about it.

 

I think there's more to it than that. The ID badge near the radiator has paint and suspension codes. In fact, when I called Tasca Volvo for a quote on some struts they asked for the suspension code and said until they had the code or the VIN number they couldn't tell me what was on my car. In a way that confirms what I've heard, that different shocks we're used along with different springs. My springs don't have a colored dot, they have a colored(Blue) brush mark that covers 2 coils. I'd like to find out how many different colors we're used and spring rates. I can't recall where or when but I seem to remember a thread about Turbos and Non Turbos not only having different shocks (gas vs oil) but the springs we're different to match.

 

I don't doubt it.

My Mercedes w124's (I have 3 different ones, a 1990 300E sedan, a 1993 300CE cabriolet, and a 1994 E320 wagon), they have this scoring system in the parts catalog... you start with a base number for the version of the car, then you add points for every option, and end up with a final score. they have 3-4 different front springs, and 3-4 different thickness spring pads, and there's a table that gives you the right springs + pads for a given score. there's also different springing for the 'sportline' factory option vs regular US. US got 'comfort' springs, in europe, the standard model was sprung stiffer and slightly lower, and in europe/world markets, there was also a raised suspension model designed for bad roads, like middle east taxi cab duty.

These Mercedes springs have various paint mark patterns on them, too. BUT... the paint dots do NOT relate to the spring numbers, you have to get the spring numbers off stamped markings.

 

Wow! And I thought Volvo was being picky. Mercedes beats them all. This kind of makes sense. I've been trying to dial in the perfect suspension for quite a while now and have tried a lot of different shock and spring combinations from what's available today. Yet I haven't been able to find the "magic ride". I owned a few Volvos years ago and I remember a good ride and good handling. Can't replicate that, yet. For a while thought my memory faded and they weren't that good. But now I understand that the choices we have have diminished and even though we're told they all fit(which they do) and that they're OEM parts...they' may not be the 'RIGHT' OEM part. Just yesterday I checked the compression rate of a brand new Sachs twin tube oil shock VS a 25 year old Volvo twin tube oil shock and I was very surprised. The Sachs(made in Mexico) took 10 lbs to start compressing and stayed at that all the way to full compression. The Volvo(made in Belgium) started at 10 lbs but gradually progressed to 20 lbs at full compression. Quite a difference. And I tried them both with the same spring and the Volvo rode better and handled better. Another obvious example is struts and front springs for a pre-'95 960. All the aftermarket suppliers say those 960's and all 740's and all 940's are interchangeable and yes, they are. But you won't get the same factory ride and handling. That 6 cyl 960 engine weighs a lot more than a 4 cyl redblock. The good news is I'm getting closer but at this point it's trial and error since no one except Moog seems to give out spring and load rates, let alone shock info. All you get is gas or oil, twin tube or mono.

 

does the alloy block I6 weigh as much or more than a cast iron redblock ? not sure.

 

the ride on these mercedes 300E/etc models, the 'model 124' family, is nothing short of sublime. the bodies are very rigid, very quiet, the suspension very compliant, they handle mountain roads at high speeds with absolutely no drama. this model, and the smaller 190 class (model 201), were the first cars with 5-way multilink IRS. I thought the 740/940's had good brakes, but wow, the brakes on these mercedes are strong and smooth and almost impossible to make fade. panic stops from high speed are drama free.

 

A 1993 940 sedan weighs 3208 lbs. The same year 960 sedan weighs 3500 lbs, a difference of 300 lbs, all in the front. Same body, same dimensions. Even though it's an alloy, add 2 more cylinders, pistons, rods and a longer cast iron crankshaft. Add dual overhead cams and it all adds up.

1993 Volvo 960 Automatic specifications, information, data, photos 226864

 

the 960 also has a lot more soundproofing, which probably adds some of that.

 

Regardless of what added the weight, do you think a car that weighs 300 lbs more is going to have the same strut and spring specs?

 

springs, probably not. struts? mercedes uses the same struts/shocks for all those regular models with the various spring weights. the sportline models use different shocks (and the wagons have an active hydropneumatic rear suspension that makes Nivomat look like a joke).

 

VADIS parts catalog lists 7 different front springs for 1993 960 wagon.

1329822 marked A2,G1. 1329823 marked AA,DC,A3,DE,G2. 1329824 marked A4,AC,45,G3. 1387677 marked A9. 6819661 marked A8 chassis 29907-/ 1387678 marked A5. 6819662 marked A1, chassis 29907-


however, unlike my mercedes catalog, the volvo catalog doesn't explain why or what the difference is between all these.

 

That's amazing. I would of guessed 2, maybe 3 at the most. I can't see how there would be 7 ride options for 1 car? Especially since the 960's we're optioned out and had no engine options and couldn't add anymore weight. Any idea what they show for a '93 wagon Turbo and non Turbo wagon?

 

huh. 940 turbo shows the same set of PNs. the two I gave chassis number range to say B6304 (i6)

also interesting. there's 3 obsolete shock absorber numbers, with codes corresponding to that A2, G1, etc stuff... all 3 map to the same replacement number...

 

Yeah, that's what I've been running across. Sachs doesn't make gas struts anymore, just the oil. And like my experiment showed, they're no match for the original Volvos. This is what I'm running into, one size fits all, but most of the time it aint anywhere near what the original was. Thinking about those 7 choices for a 960, maybe the suspension engineers realized they can't have their top of the line luxury car ride like a 740/940 so they kept changing specs as the line evolved?

 

You know, that's one thing that's puzzled me since I got back into these cars. During that mid '90's time frame Volvo tried to emulate(to compete with) BMW and Mercedes. And they succeeded in a lot of areas. But as far as suspensions they missed the boat. I've never driven a mid '90 BMW or Mercedes that rode as hard as a Volvo yet they handled as well or better. I can't figure out why. Granted A frame front ends are better engineered for controlling ride and handling but a lousy Toyota Camry from that era had MacPhersons and strut rods to locate them and they feel like limos compared to these Volvos. They should have hired Lotus like Isuzu did.

 

a late 80s Mercedes 300E was a $60,000 car new. same era 240/740 was under $20K. even the top of the line 780 Bertone, which btw, had a fantastic ride *and* handling when new (I owned a 1989 new for 6 months) was $35K.

 

That's interesting, because the 780's have the same front suspension as all 740's and all 940's. I know the rear was IRS but what made the front ride better? That's where my project is right now, the rear of my wagon is dialed in.

 

i think the 740 body/chassis might have been more rigid and had better soundproofing. the rear IRS definitely tracked the road nicer than a live axle, new everything helped a lot, too, I'm sure my 780 was the V6, which I know was problematic but man it was a smooth ride.

 

With that heavy V6 I'm guessing it had diesel springs upfront. Do you know if the struts we're gas or oil? Either way that sure doesn't sound like my 940. While I'm testing I've even disconnected the sway bar and I still feel every tar strip and cement crack. And it bounces over even medium bumps instead of absorbing them. The strut mounts look fine and I replaced the control arm bushings last year. Don't know what else it could be. Maybe I need to replace every bushing that's rubber. Cuz even though Volvo bushings can still look good after 25 years ALL rubber hardens as it gets older. I do remember the smoothest ride I've ever owned - a 2003 Lexus GS 300. In line 6, rwd and the same overall weight and dimensions as a 940. One day the ride hardened and it was the control arm bushing. Replaced the whole arm(the bushing was fused into it) and the ride returned. Those bushings we're foam rubber compared to Volvo's. The downside was they wore out twice as fast but the ride was worth it. Here's what really shocked me, I just looked up the spring rate of the front springs and they're 144 lbs! 60% stiffer than Volvo's(mine measured 90 lbs on my homemade scale). Yet, in my opinion, the ride was 60% smoother and it handled great. So, to me, springs aren't the main factor in engineering a smooth ride. It's gotta be bushings and shocks. I'm thinking the stock Volvo shocks have too much compression and not enough rebound(my cars tends to fall into pot holes instead of gliding over them). What do you think?
Another thing I noticed the other day when I was working on my car and had the control arm off was the lack of movement of the strut rod where it attaches to the frame. It's torqued to specs, about 60 lbs I believe. But when i grabbed the other end to move it around and see if the bushing was ok it didn't move vertically very much. It only moved as much as the bushing would deflect. Shouldn't it pivot around the mounting bolt as it moves up and down following the movement of the strut? If it's restricted then it must restrict the movement of the strut. That would destroy the ride. Maybe?