I have had it with the rear end sag and i am currently pricing parts. my question is what should i replace as far as rubber bits. Also what combination do i do.
i was thinking for the rear, HD Springs and shocks and just regular bilstein shocks for the front and not messing with the springs up front.

any suggestions and what others have done? success? failures?

I just posted this in another context. Have you checked the rear subframe bushings?

Sixto
87 300D

I've spent quite a bit of time with the ride height of the W126. The approach that I took with the SD differed from the approach with the SDL.

To get the ride height back to perfection with the SDL required a set of new springs. However, after purchasing the stock springs, I find that the vehicle still sat low in the rear with any load whatsoever in fuel or in baggage. To get the proper height required some custom springs with an additional 5/8" length. The vehicle now sits a tad high in the rear with no weight. I might lower it slightly with thinner pads.

The SD was quite successful by using the stock springs. The diff mount was replaced and the spring pads were replaced to the maximum thickness three nub pads. The main success on the SD was accomplished by replacing the front spring pads with the very thinnest possible one nub pads. This cured the high front end look and simultaneously raised the rear slightly. The vehicle sits perfectly now...........just slightly high in the rear with no weight and dead level with full fuel and about 50 lb. in the trunk.

So, before you waste a bunch of money on springs, determine if a change of pads and the replacement of the diff mount will cure your problem.

Brain
thanks for the information, the diff mount has been replaced. no noticeable difference. very interesting about the pads, i will give it a try. Should i go with the HD Shocks on the front and rear or just rear? what about the koni shocks?

I'm not a champion of "HD" shocks on the W126. The ride is mediocre at best and the slight handling advantage of the HD shocks isn't worth the beating that you'll take on a daily basis.

No experience with Koni. Bilstein usually gets the nod here.

To "lift" my rear end on my 420SEL, I replaced:

Springs - stock OE
Spring pads - stock (can't remember which nub off the top of my head) OE
Subframe bushings - stock OE
Trailing arm bushings - stock OE
Diff mount - stock OE
Shocks - Bilstien Comfort

By doing this, I gained just under 2" of ride height in the rear.

__________________
1986 420SEL W/1990 560 SEL Full Power Interior Swap
1995 E300D
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My 85 300SD sagged in the rear also. I put H.D. springs + H.D. Bilsteins and with a lot of weight in it still sags more then I would like and the wheels sit like this / \ . My next step will be to either put some kind of shim under the spring or would really like to custom fit some air shocks on it so I could put the height wherever I need it. Really fed up with this sagging also.

I heard a 69 firebird air shock will fit our cars

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

SLS...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

For a 1984 300SD would the part number for the front Bilstein shocks be Part Number: W0133-1910719? Fastlane has them for approx $65/ea...

These are OEM, correct?

Thanks ya'll!

A 1984 300SD would more likely have Boge or Sachs shocks than Bilstein as OE. The Worldpac part number I see on Fastlane for Bilstein comfort front shocks for that car is W0133-1910423.

Bilstein offers comfort/touring (24-011839), heavy duty (24-005012) and performance/lowered shocks (24-015356) front shocks for that car.

Sixto
87 300D^2

To eliminate rear end sag you must change your Differential Mount AND Subframe Bushings (the two very large round ones).

This is going to sound snooty but forgive me:

The w126 subframe architecture is such that the diff mount and subframe bushings work IN CONJUNCTION with eachother to create a positive-camber platform. If any of those 3 rubber bits weakens or fails, the leveraging effect of the system fails, you lose camber, undue force is put on the springs, and the car saggs.

Also, asymetrical rear end sagging is almost always due to asymetry within the system (i.e. One subframe bushing is bad)

Only after this subframe system fails does excessive pressure begin to be placed on the shocks and springs, leading to their loss of strength, thus exaserbating the sagging further.

I run my SDL on VO. When the 2nd tank is full, that is 175lbs in the trunk. When I take a road trip I start off with about 500lbs of extra fuel plus luggage.

I got spring helpers. They are the kind that screw into the spring with a 1/2" drive on an extension and a breaker bar. The one's I get are marketed for the front springs for a pick-up ( the rear one's are too big ). They cost about $10. They take just a few minutes to install.

They may not work for you. Others will be aghast at such an idea. For $10, it just might be worth a try.

No sag. No noticeable degradation of the ride. 50k on the SDL, 130k on the W210 with no problems.

__________________
Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

While I am in agreement with the three point support that provides the basis for the subframe support and the ultimate ride height, I disagree with the premise that the subframe bushings are going to effect a significant difference.

The reason is as follows:

1) The rubber in the subframe bushing can collapse fully and the body of the vehicle will fall not more than 1/2". This is if the bushing fully collapses and disintegrates which for most folks hasn't happened yet.. If this does occur, the geometry might allow the body to fall a maximum of 3/4".


While it would be desirable to recover that 3/4", most vehicles won't benefit by more than 3/8" when the subframe bushings are replaced. My previous experience with the SDL shows that you can spend your money elsewhere (spring pads, differential mount, shocks) for more gain.

Installing new Bilstein shocks gave the SD an additional 1/2" just from the proper gas pressure.

Bags. If I get a nicer 300sd I'm putting it on bags.

__________________
1982 300sd from craigslist $800 greased on one tank with NO CONVERSION in the Hot Texas Sun. (currently dead & awaiting engine damage investigation and/or longblock swap)
new daily: '03 vw 5speed jetta tdi wagon. bagged&chipped