Will this work to drop the subframe?
 

Getting ready to tackle a monster job on my '83 300CD

Need to change out:
-subframe bushings
-differential mount
-CVJs
-rear bearings
-trailing arm bushings

apparently for the trailing arm bushings, the subrame has to be dropped

just wondering if this will work: Pelican Parts.com - AC Floor Jack Cross Beam Adaptor

There is a jack adapter that is in the FSM for lowering the subrame and differential, but I can't find it, and if I did its probably super expensive.

any thoughts?

If you're looking to do all that work, which is a great idea all at the same time, then try to disconnect the entire rear end / rear subframe from the body.

It can be done with the rear wheels still attached and the whole unit will roll out from underneath the car.

Brakes and parking brake must be disconnected as well as driveshaft.

Seems like a lot of work... but worth if you're doing the axles and all that rubber.

you won't need any special tools. other than what you use to press the rubber in.

a floor jack will suffice if you have good jack points and 2 MB stock jacks.

When did mine, I used 3 floor jacks. One under each Trailing Arm, and one under the diff.
Once the DL, Shocks, Calipers etc... are disconnected, just roll the assembly out from under the car.
If you are on create it is easy.

When you install it, roll it under and then lift up, Connect the Sub Frame Bolts, install the springs and rubber pad.
Lift up making sure the Springs are in their pockets.
Then put in the 4 13mm bolts for the Diff Mount.

There is a number of ways to do it.

If you are interested in the cross piece for the jack you posted that Pelican shows.
Harbor freight has it and on sale for $39.99.

Steel Floor Jack Cross Beam


Charlie

Sent from my pos computer

I strongly recommend the vehicle is secured from rolling forward or back with chocks or straps.

I would think that you could use a piece of 2x4 to achieve the same effect... maybe a 2x4 with an additional piece of 2x4 at each end, with a bolt running through the center to attach it to a jack. Like this:

http://www.peachparts.com/shopforum/...1&d=1444919589

Shame on the two of us giving info and leaving out safety. :o

That is the most important part of the project. You need to have the vehicle safely secure so it will not roll or move in any way.

When I removed the Sub Frame assy out of the 85, then went back under the car, it gave me the hebbie jebbies thinking...what if? :smhair2: :eek:

I placed a stack of mounted tires under each side for just incase.

Before I did the job, I called Roy (Whunter) how to safely support the car when there is basically only sheet metal to support it. Was afraid of bending something.

Roy said to use some rod in the Jack Hole and place the jack Stands under them.

Rooster300SD posted here how he did it.

http://www.peachparts.com/shopforum/diesel-discussion/371334-replace-trailing-arm-subframe.html


http://www.peachparts.com/shopforum/...e-img_7103.jpg http://www.peachparts.com/shopforum/...e-img_7104.jpg

__________________

I had a Fab Shop make mine, 3/4" rod into the holes, left about 6" out, then bend 15deg so they were level.

If your jack holes are rusted out, then that changes things, you have no structural support.


Charlie


sent from my pos computer

really my only reason for dropping the subframe is the 4 bushings in the trailing arms.

I prefer to do all the other rubber bits and bearing with the subframe on the car.

With that said, i'll probably just do the 4 bushings first, then mounts, then axles and bearings.

it seems like the bearings will be the toughest part of this undertaking. therefore it will be done last.

funny how the most work is done to change out the least expensive parts.
trailing arm bushings are $7 a piece lemforders

oh well, at least the whole front end is done.

I always laid a 2x4 along the subframe and put my jack under that. I never trusted the jack points.

did the same job - Subframe Refurb
 

Did this last year myself. Also would not trust the jack holes.

While it's all apart, you might want to replace the diff seals, too. I also replaced drive shaft center bearing and bearing mount. Just easy and cheap while you're in there.

And - dunno the miles on your axles - but rebuild of these was the driver of my project. Per advice from guys here, I reversed them on re-fit to put the stresses on the opposite faces for the next 300k miles!

If I lived in the Salt/Rust belt, I wouldn`t trust the Jack Holes either.


Charlie


Sent from my pos computer

I've used all thread placed thru the shock mounts to lower and install the rear SF ass'y solo. floor jack under the diff.

I used a short 2x4 block on the bottom of the threaded rod where the lower shock mt is.

Chocks, are very important. When you have no idea whether the emergency brake is usable. I learned this just this month when working on my Nephew's Jeep that was on a mild incline city street to try to ascertain where a coolant leak was originating from. I had him engage the E brake, but failed to see whether it was actually operational when checking out the Jeep w/o chocks. Later, I tried the E brake while fueling it, and learned it was 'no-good.' Just lucky earlier is all. I learned something new - yet again to not rely on, w/o knowing, or, chocking the vehicle, just in case.

In my garage - I use both jack-pads, and, under-frame, superstructure/frame area support on the MB. :yes: