Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
1973 450 SL
Joined
·
1,769 Posts
Discussion Starter #1
I finally tackled this last Thursday. Many here have accomplished this and written about results. I just want to add a few lessons learned that I think will help others. It is possible to do this with the engine and transmission in place.

1. Disconnect the control pressure rod ball socket at rear of engine. I used a large flat head screw driver to pop it off. (part 68 from part 11 in first picture)

2. With car on jack stands, slide under and locate the control pressure lever on the right side of the transmission (part 355 in second picture). Take 2 x 10 mm wrenches with you; the longer the better, if one has a deep offset, better yet. Also take a big flat head screw driver and a good light.

3. Remove the bolt that holds the control pressure lever to the transmission (parts 356 and 358 in second picture).

4. You will see a gap in the bottom of the control pressure lever that is clamped closed by the bolt you just removed (gap is depicted in bottom curve of part 355). Pry that open a little to allow the lever to be removed. At this point you will notice that the control pressure lever mounts to the transmission stub that has a rectangular shaped collar. This is important because the lever can only be remounted at the correct fixed angle. The only adjustment to this assembly is made at the forward end (screw action of part 68).

5. This step took me an hour to figure out. The control pressure rod and lever will come up through the engine bay if you first manipulate the aft part of the assembly (the part you just disconnected) to a position above the transmission. Continue that movement until the assembly is lying diagonally across the top of the transmission (front right / back left from driver's perspective). This allows the curves in the rod to move up through the tight space near the firewall. Don't worry, it goes back in easily if you reverse the process.

6. Remove the cotter pin and washer (parts 77 and 74) then separate the control pressure lever (355) from the control pressure rod (59).

7. Clean the entire assembly and examine the eye socket at the aft end of the control pressure rod (59). You will see that one side of this socket is flat, the other side is beveled.

8. Examine your new bushing (MB part 110 277 05 50 - #62 in EPC diagram). One side is flat, the other is tapered. Match the taper to the bevel and press into place. I used a wooden bench vise and silicone.

9. Reverse steps to install. I struggled getting the bolt back in (30' and some bad words)

My test drive resulted in late (high engine rev) shifts. The new bushing had the effect of rotating the control pressure lever forward a few degrees. I lengthened the assembly by unscrewing part 68 by two turns and now it is perfect. I am amazed at how much change is produced by a couple of turns of part 68.

Faithfully submitted,
 

Attachments

·
Premium Member
'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
Joined
·
10,015 Posts
Yes - very nice clear write up cush.

When I did same job, I didn't remove the control rod. I removed the lever as described, but then just lowered it, removed the cotter pin and installed a new bushing. Worked for me and improved shifts once re-adjusted.
 

·
Registered
1977 450 SEL 6.9
Joined
·
727 Posts
To close the loop on this, very late I know:) This is a must check for anyone with this control pressure rod setup. The bushing is cheap and relatively easy to replace. The difference in the way the trans will shift after is profound, well worth the effort.
 
1 - 5 of 5 Posts
Top