450 sl "Mushy" suspension

[smallblock450sl]

Had the 450 out for a nice cruise yesterday. My problem is the "Mushy/Soft" feeling of the suspension ride. I have new (stock) coil springs (just installed) newer shocks on back and new shocks on front. It seems to me to "Float" on flat roads. It seems to corner fine but just feels funny. I would think better shocks could help but only in the "rebounding" sence. Any Ideas or suggestions would be great. PS- Isnt it amazing the world you see with the top off !

[RickM]

When refreshing the suspension on my 380 I replaced the rear subframe mounts, rear springs (with 560SL units) and installed Bilstien Comfort shocks. The ride is beautiful and the rear is kept at the proper rake.

That said it still isn't as crisp as other cars with a modern suspension. Additionally, the weight contributes to the floaty feel.

[smallblock450sl]

Originally Posted by RickM

When refreshing the suspension on my 380 I replaced the rear subframe mounts, rear springs (with 560SL units) and installed Bilstien Comfort shocks. The ride is beautiful and the rear is kept at the proper rake.

That said it still isn't as crisp as other cars with a modern suspension. Additionally, the weight contributes to the floaty feel.

I was thinking about new sub frame mounts (front and rear) but they dont look bad. Why did you use "560" springs ? There are alot of 3800 lbs cars, I don't think thats the problem. Well maybe i'll just bite the bullit...buy the aftermarket "sport" springs (795.00) and some Bilstiens and enjoy the car for what it is "FUN". Thanks for the input. Dave

[RickM]

Originally Posted by smallblock450sl

I was thinking about new sub frame mounts (front and rear) but they dont look bad. Why did you use "560" springs ? There are alot of 3800 lbs cars, I don't think thats the problem. Well maybe i'll just bite the bullit...buy the aftermarket "sport" springs (795.00) and some Bilstiens and enjoy the car for what it is "FUN". Thanks for the input. Dave

Dave,

The rear of my 380 sagged when I purchased. The 560 springs are taller and supposedly taughter. I did notice a ride height and ride difference. If you search on "RickM" and "Springs" you'll find a side-by-side comparison.

To be honest unless your sub frame mounts are very worn I wouldn't replace. Mine didn't appear worn and replacing yielded no appreciable benefit.

[Roncallo]

Originally Posted by smallblock450sl

Had the 450 out for a nice cruise yesterday. My problem is the "Mushy/Soft" feeling of the suspension ride. I have new (stock) coil springs (just installed) newer shocks on back and new shocks on front. It seems to me to "Float" on flat roads. It seems to corner fine but just feels funny. I would think better shocks could help but only in the "rebounding" sence. Any Ideas or suggestions would be great. PS- Isnt it amazing the world you see with the top off !

Did you happen to get a weight comparison of the small block (I assume Chevy) and the weight of the original 117 engin. I believ the Chevy should be lighter that should make the ride feel stiff if no other mods were done. Also do you happen to have the part number of your old 450SL springs. I might be interested in them if you still have them. Also who sells custom springs for this car. I will be looking for some for my 560SL.

John Roncallo

[London380sl]

For custom springs try this link. Aproximately $800 a set according to the ad.

http://www.slmarket.com/springs.htm

[smallblock450sl]

Originally Posted by Roncallo

Did you happen to get a weight comparison of the small block (I assume Chevy) and the weight of the original 117 engin. I believ the Chevy should be lighter that should make the ride feel stiff if no other mods were done. Also do you happen to have the part number of your old 450SL springs. I might be interested in them if you still have them. Also who sells custom springs for this car. I will be looking for some for my 560SL.

John Roncallo

John I purchased the "stock" springs from German Star. Part# 1143210604 @78.00 each for fronts, Part#1153242204 @69.00 each for rears. I've found "lowering springs a Johnson performance @323.00 full set @ 443-557-0086, but have not contacted them yet. I 'm going to look into "London380sl's" quote/link-looks like the ticket for me. Thanks to all and thanks to London380sl....I knew I saw that website before, but could not find any links the last couple of days. Later Dave

[nobby]

Originally Posted by smallblock450sl

I was thinking about new sub frame mounts (front and rear) but they dont look bad.

Don't be fooled by what you see.
Subframe mounts compress over time and get hard. Of course if the front ones have ANY oil on them they could be soft.
If they have never been changed then they are due. Regardless.
I noticed a huge difference.

[ScottinSoCal]

Originally Posted by nobby

Don't be fooled by what you see.
Subframe mounts compress over time and get hard. Of course if the front ones have ANY oil on them they could be soft.
If they have never been changed then they are due. Regardless.
I noticed a huge difference.

Ditto. I changed the subframe mounts on both cars (75 450SL and 78 450SL) and there was an immediate improvement in handling and ride comfort. The 78 mounts looked fine, even when I sat them next to the new mounts there was less than 1/4" difference in height. But the car stopped trying to follow every rut in the road and turns stopped being quite as dramatic. When I changed the bushings for the sway bar it improved again, and when I replaced the cheap aftermarket shocks with some good Bilsteins it was just about perfect.

[smallblock450sl]

Originally Posted by ScottinSoCal

Ditto. I changed the subframe mounts on both cars (75 450SL and 78 450SL) and there was an immediate improvement in handling and ride comfort. The 78 mounts looked fine, even when I sat them next to the new mounts there was less than 1/4" difference in height. But the car stopped trying to follow every rut in the road and turns stopped being quite as dramatic. When I changed the bushings for the sway bar it improved again, and when I replaced the cheap aftermarket shocks with some good Bilsteins it was just about perfect.

Thanks for the input....Did your car seem "Floaty/soft" riding before your upgrades ? Just another note...If I push down on the front or rear bumpers, the suspension is "soft", the shocks seem to work it doesn't keep bouncing like worn shocks would. There are no squeeks from the undercarrage. More info, More awnsers ? Thanks Dave

[ScottinSoCal]

Originally Posted by smallblock450sl

Thanks for the input....Did your car seem "Floaty/soft" riding before your upgrades ? Just another note...If I push down on the front or rear bumpers, the suspension is "soft", the shocks seem to work it doesn't keep bouncing like worn shocks would. There are no squeeks from the undercarrage. More info, More awnsers ? Thanks Dave

Mine was very floaty - it felt like I was just above the road instead of on it. I started asking about handling and suspension when I first bought it, because it just didn't handle like I expected. Everything I did on it improved it a bit more, starting with replacing the front subframe mounts, then the rear, then front lower control arm bushings, then the steering damper, then installing an idler arm kit, then tie rods and finally the new shocks. When I bought the 75 the suspension was in the same condition as my 78 had been, and it was really surprising to see how much difference all that made.

I also did the bounce test on my 78 for my shocks, and it passed with flying colors, but the new shocks made a big difference in the way it felt. I felt more connected to the road and the steering input I was used to (just not in the SL) was all there.

I did all my own labor, so the parts were the only cost. It came up to about $600 all total for the whole suspension rebuild. If you had it done, of course, the labor would cost you. But it really isn't that bad. I just did the same thing for my 75 and it only took me a day.

[smallblock450sl]

I installed the new Bilstein "HD" shocks yesterday, What a differance ! First I installed the front shocks and took a ride......The improvement was amazing ! Then I installed the rear shocks , (for previous posters....Bilsteins web site does not carry a "HD" only "comfort" rear shock..mine came as "HD" but I could only find them listed for a "SEL" on the Bilstien website) In my opinion they are alittle stiff, Maybe confort would be the better choise. I am very pleased with the ride with the new "stock" coil springs and new shocks. I would recomend Bilstein's "HD" front shocks to everyone. Later Dave