After the rear axle is installed, the front axle parts begin their journey home. Different from the rear axle strategy, most parts of the front axle are installed after the subframe is married to the body. This is due to the limitations of the V12. Generally speaking, in order to achieve balance on a 2-post lift, you need to install the rear axle first and then the front axle, because the front of the car is much heavier. A body with complete front axle and engine but lack of rear axle is tends to tilt on the lift.
Due to the lack of hydraulics and differentials, the double-wishbone front axle looks simpler than the rear axle, includes the subframe and left and right control arms. In fact, the work on the front axle also includes group 24 Engine Suspension, 32 Springs, 42 Brakes, and 46 Steering, which is not that simple. The front axle installation of Ocatvius is not very representative, our plan is to first marry the subframe to the body, and then install the suspension, brakes, and engine.
This is because with the 6 and 8-cylinder models there is enough space to mount the subframe with the engine and suspension directly to the car, but the 12-cylinder is another story. At least for the LH-Jetronic 120.980 it is very difficult, the throttle body control mechanism on the side of the intake manifold increases the overall width of the engine, it cannot pass through the wheel arch from underneath. It is possible to remove the LH control mechanism and mount the engine and subframe to the body from below, but it is very difficult to install the control mechanism separately on the side.
At least according to the factory photos, the V12 does require a crane to get the engine assembly installed from above, rather than from below like other models.
24 Engine Suspension
The subframe was simply pre-assembled before the marriage, which included installing the engine mount. The hydraulic engine mount is the most typical technological highlight of the 140 era. Compared with the solid rubber of 126’s, the 140 hydraulic mount can provide a better NVH experience, but is also more expensive and sensitive. Due to the extra weight of the V12, the engine mount appears more fragile. The typical problem is that the rubber loses its support and the engine is directly connected to the metal casing of the engine mount, transmitting vibrations. Therefore, genuine parts are used to prolong life and avoid complicated repairs.
The engine mounts on both sides of the V12 have screening plates, but Octavius only has one left when we disassembly it. So 2 NOS were ordered and refined appropriately, and new fasteners gave the entire area a brand new look.
The mount at the rear of the gearbox is also classified by EPC as part of the engine suspension. Although the gearbox has been completely restored, we are in no rush to install the transmission to the engine for this article.
33 Front Axle
The front subframe was painted together with the rear few months ago, which included PPG marine prime and black epoxy. Some extra time was spent trying to clean out the dirt inside with compressed air – there was much more dirt inside the front subframe than the .
The four rubber mounts were replaced and an earlier repair kit was used. There is a bug in the current EPC where each part must be ordered individually as the repair kit is no longer available. The front and rear rubber bushings are different and each requires 2 pieces. However, the order quantity of A1403311444 is 1. I tried ordering one and received one instead of a pair. Obviously you need 2.
The upper control arms replaced few years ago, and despite only having very little mileage, they have definitely aged cosmetically. I managed to make them look like fresh new again while adding extra protection to make them relatively durable. For example, the exposed zinc plated surface of the joint is covered with a protective film, which can prevent oxidation and rust. The refined genuine part is definitely a better choice than the recent LEMFÖRDER replacement.
The lower control arm’s 6 bushings were also replaced, four smaller ones in the front and two larger ones in the rear. The rear bushing is hydraulic, an improved design since 1992. Of course be careful about the authenticity of such part, I purchased a pair of purported genuine NOS from a trust parts dealer but they have no part number on the rubber. The result is that they cannot be squeezed into the control arm. For these hydraulic bushings, some fluid will be squeezed out during the installation process, so it is important to ensure one-time installation. Non-compliant bushing may require repeated attempts or even damage to the bushing, so don’t waste time and money trying to save expense here.
The lightly assembled subframe is joined to the body using a flatbed lift as planned. The lower control arm is installed after the subframe is married to the body. The lower control arm and spring are compressed by tightening the nut on the long screw. Since the compressed part is between the subframe and the lower swing arm, the body of the lift will not move. If you directly try to push the lower control arm with a spring onto the body, the body will undoubtedly tilt and cause danger.
32 Springs,Suspension And Hydraulics
The Bilstein front shock absorbers were abandoned after only a few thousand kilometers! Ordered the new Genuine shocks and it is actually exactly the same. The replacement Bilstein does have some cosmetic deterioration and will be used on lower grade projects. A full restoration is just like that, don’t miss out on the possibility of perfection if you get the chance.
Extensive research was also done on front shock absorbers during this period, see <Parts: Front Shock Absorbers>.
The required pad thickness was confirmed according to the factory form: 8 mm, 5 mm less than the part on car. I repeatedly confirmed that the points calculated based on the configuration are the thinnest. Ocatavius is indeed a V12 without many options. You can say that it could be one of the lightest V12. But the suspension height still awaits verification, which must be determined after engine installation and self-leveling work. If necessary, replace the pad with a thicker one according to the actual situation.
Another tricky thing about EPC: the front torsion bar is classified as front suspension rather than front axle, and both control arms belong to front axle. And the lower control arm is part of the front axle, not the front suspension. Processes should be formulated based on actual needs, rather than according to EPC or even WIS classification.
42 Brakes
All brake components were replaced, from the 10kg brake disc to very small parts. I had planned to rebuild the calipers, but the two smallest O-rings were not included from the repair kit, and these two O-rings could not be ignored. There is no need to disassemble the calipers without replacing them, so just disassemble and reassemble one of them. Even the botls were zinc plated and then had to be installed and spray painted black along with the calipers. Well, this is what it looks like out of the factory.
The rear brakes were also installed and the rear axle is now complete. The car is about to leave the lift, waiting for the engine to be installed.
46 Steering
Light front axle assembly at start of this thread would also ideally include the steering gear. The 140 does not have a traditional rack and pinion steering gear, but a recirculating ball steering gear plus some connecting rods.
The 140 has two steering tie rods, which are located on both sides of the drag link. Unlike common rack-and-pinion steering cars, the 140’s tie rod is not connected to the steering rack, but through intermediate lever. We also compared different tie rods in <Parts: Steering Tie Rod comparison> and concluded that LEMFÖRDER is only suitable for installation on lower-level projects.
The kinship with the W240 doesn’t make the MAYBACH more affordable, it just cost our low-end S-class more premium. Idler arm bearing of 140 is now offered by MB as MAYBACH part, no other choice. The febi Bilstein counterpart is very poor.
Will there be conscientious dealer technicians who are motivated to remove the excess stickers on genuine parts?If this were not part of the SOP, the suspension would be full of stickers.For the steering damper, there is no difference between Genuine and Stabilus other than 4 stickers. Stabilus just has the advantage of sticker-free.
Let us breathe a sigh of relief, the longest and harders job on Octavius is over. The following is the overall after & before. The front axle and barkes are officially done!
