How-To: E46 Rear Chassis Reinforcement Plate Install
- Part Name: E46 BMW Rear Chassis Reinforcement Plates
- Part Number: K0117
- Part Page: https://www.garagistic.com/products/e46-bmw-rear-chassis-reinforcement-plates?_pos=3&_psq=e46-reinf&_ss=e&_v=1.0
- Difficulty Level: 10
- Wire wheel/brush to prep surfaces for welding
- Jack and jack stands
- Basic Ratchet and Socket Set
- Electric Impact
- Small Pick or Screwdriver
Installing Subframe reinforcement plates can be a daunting task for novice mechanics. As such we always recommend having a welding professional install these plates as they are welded on to structural parts of your chassis. This guide will go over preparation and placement of the brackets.
As seen below the two identical plates are mounted at the front two subframe mounts and the two larger plates mount at the rear. They are designed to contour the body for ease of welding.
Before you begin this installation the entire rear end of the vehicle must be removed along with the fuel tank and evap parts including the charcoal canister. Below you will find a link to our subframe removal guide.
Fuel Tank Removal
Before the fuel tank can be removed you'll first need to remove the rear seat bench. This can be done in a matter of seconds by simply lifting the rear seat upwards. Some effort will be required to release it from its clips.
Once the seat has been removed you will find two large black metal covers. Unscrew the 4 10mm Bolts from each and move them to the side.
Below the covers, you will find the fuel tank lines and wiring for the fuel pump and sending unit. Release the electrical connectors from both and then carefully remove each hose from the fuel pump and sending unit.
Next go under the vehicle. You will need to use a 10mm socket to release the nut holding then filler neck to the body. Once this is done use a screwdriver to release the hose clamps on the rubber hose that connects the filler neck to the fuel tank.
Once the filler neck is released you can lower the tank. To do so support the tank from underneath with a friend or a pair of jacks. Unbolt the 3 13mm bolts holding the tank to the body. Release the fuel tank straps by rotating the down and then pushing them up towards the top of the car.
Begin lowering the tank and from the front side keep an eye on the lines that are attached to the tank. Some of them will need to be released and moved out of the way as the tank is lowered. Once the tank is lowered. If you are on jack stands you will be able to move it out of the way to clean and weld your reinforcement plates in.
Cleaning and Prepping Plates
Before installing your subframe reinforcement plates you will first need to prepare or clean the metal you are welding to. Below are a few tools you can use to help you clean everything. For this guide we used a seam sealer removal wheel and a wire brush on a drill. Roloc wheels are another excellent way to remove paint and underbody coating.
Using the seams sealer removal wheel pictured far right above begin to clean the metal around each subframe pickup point. This is done not only to prepare the metal but to inspect for any cracks that may not yet be visible as sometimes they can be hidden under seam sealer or underbody coatings. See below reference photos for an idea of how much material you should clean. It's always good to go a little further than the plates. This makes welding easier and helps find cracks!
Once you have cleaned the areas surrounding the plates with the removal wheel. Take your wire wheel and go over everything again. This will help ensure no paint or other unwanted materials are left on the body. These can ruin a good weld and make things a little more difficult for you or your welder.
Take your wire wheel and clean all areas on the reinforcement plates that are to be welded. This removed any machining oils or coatings that may be on the plates and will help ensure you get the cleanest welds possible.
Using the supplied hardware and/or the bolts from the trailing arm brackets, bolt the plates up to the body. Make sure to line them up as close as possible to the chassis leaving minimal gaps.
Once everything is in place you may begin welding! Once everything is in allow the metal to cool before applying a coat of paint to the bare metal. Rust-o-leum High-Performance paints are a great product to cover these areas. It is very chip-resistant and won't crack over time being in a high-stress area.