Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Welding In Reinforcement Plate (Sheet Steel) Rep-REP-RAGRP41-4105801-V.5 (M3 Base, M3 Competition, M3 Competition M xDrive, M3 CS)
In the case of a partial replacement piece, a body part is cut at a point described in the repair instructions
A reinforcement plate is welded in to ensure sufficient strength
Comply with notes on WELDING OF STEEL COMPONENTSΒ .
Mark component in accordance with dimension A and cut
Cut new part (1) in accordance with cut and, if necessary, adjust to fit with set of alignment brackets or universal fixture
Installation note:Β
Leave a space on the separating cut of about one to max. two material thicknesses to ensure the weld with the reinforcement plate and allow for adjusting
Clean the connection areas (1) at the new part and (2) at the body each at the inner and outer sides
Coat the insides with a layer of welding primer
Drill holes (1) and (2) at a distance of 25 mm apart
Drill diameter: about 8 mm
Cut the reinforcement plate (1) out of the new part trim
Cut out additional reinforcement plates as needed
The length of the reinforcement plate is at least 40 millimeters
Coat reinforcement plates (1) and (2) on both sides with welding primer
Carefully slide reinforcement plate (1) half-way into component on the body and plug weld (2)
If necessary, adjust new part (1) to fit with alignment bracket or universal fixture and plug weld (2)
MAG weld the joints (3)
Sand and clean the weld seam and plug weld
In visible areas of the outer skin and on the carrier support, areas that have been ground should be washed/tinned
Do not wash/tin any areas covered by covers on the vehicle
European used-vehicle regulations prohibit the use of tin containing lead in cars introduced after 01.07.2003!
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.