300SD Rear Air Shock Retrofit?
 

Hey alls..


So I just replaced the rear springs and spring buffers on my '83 300SD. It had the heaviest springs and the thickest pads in it originally.. so I ordered Bilstein springs and the thickest pads to replace them.



After installation, the rear sits a little higher.. but it is still too low with anything put in the trunk and I can't stand it.


With that said, I've ordered some stubby "HiJacker" air shocks with standard eyelets on both ends. They were originally for a mid 70s beetle with a compressed length of 10" and expaneded length of ~16".


My plan is to compress the suspension as far as I want it to go that prevents tire rub (car has larger than factory tires)... compress the shock and make mounts. A simple "U" mount that will weld to the top side of the trailing arms right next to the spring base... then do the same to the top except with a larger plate to reinforce the area they will be mounted to.


From what I can see under the car, there is plenty of room. This will give me the ability to adjust the firmness of the ride and carrying capacity on the fly.


The car has a hitch installed by the previous owner so the idea of pulling my little utility trailer has crossed my mind. Also, I like to be able to carry tools between jobs and I don't want to keep stressing the stock springs/shocks. I figure this may be a cheap way to prevent premature failure of the new springs and shocks.. along with maintaining suspension geometry/alignment while loaded (reducing tire wear).


I've seen a few people who've done this on the wagons but they used the stud type mount air shocks and had issues with the sheet metal tearing. I figure the eyelet type and a reinforced mount would solve that.


Am I overlooking anything? I also plan to lengthen the bump stops.

Did you order 126 or 116 springs? I've found that the 126 springs always sag, even with the 3-nub spacers. The 116 springs have a higher spring rate and will make the car sit with a slight rake with the 3-nub spacers, even on a longbody car like my 560SEL.

Ordered 126 springs from Pelican. Figured that's what I needed. They seem to be too soft. The ride quality is great... but don't seem to like the weight of the car.

The ones I ordered do have a "116" part code...


https://www.pelicanparts.com/More_Info/1163241104.htm?pn=116-324-11-04-M1412&SVSVSI=3337&DID=279

ABR:
There is a spring with both a higher rate and slightly greater length:
116 324 09 04

Look at this post I made, I can't seem to reattach the images I robbed from somebody else years ago.

http://www.peachparts.com/shopforum/3981450-post16.html

Stock on my 82 W123 Sedans is 1233243604 (371mm length or 14.6", 19.1mm travel per 1000N)
I installed 1163240804 (Technically the same length, just much stiffer so it sits A LOT higher, 373mm length 14.68", 16.6 mm travel per 1000N)

It's not just the tire wear that you should worry about but also your cv axles will run at an angle reducing the life of the boots/joints

I would like to see this as a finished product with a walk thru. Interested in doing something similar

I don't know if this is the issue re-attaching the pics. But, if you try to re-attach a pic and it tells you the pic is already in a thread and gives you that thread what works for me is you take that pic and rename it. Open it in Edit and resize it. After that they will normally attach again.