Front Subframe: Service and Repair
Subframe
Special tools, testers and auxiliary items required
• The following tools can be used on all engine versions. The tools needed for working on a specific engine are described.
• Engine Support Bridge (10 - 222 A)
• Adapter (10 - 222 A /22)
• Bracket with Spindle and Hook (10 - 222 A /10)
• Engine Sling (2024 A)
• Engine Support Basic Set (T40091)
• Engine Support Supplement Set (T40093)
• Engine Support (T10014) (only needed with 3.0L TDI)
• Ball Joint Puller (T10187)
• Hose Clamps Up to 25 mm Dia. (3094)
• Scissor Lift Table (VAS 6131)
• Supplementary Set, Audi A8 (D3) (VAS 6131/10)
• Supplementary Set (VAS 6131/11)
• Supplementary Set, Audi Q7 (VAS 6131/13)
Removing
Description
Subframe is removed using scissor lift table. Front mounting points of engine carrier must be secured using shorter bolts. Subframe is removed together with the following: Steering gear, front axle drive, lower control arm and wheel bearing housing. The suspension struts with mounting brackets and upper control arms remain on vehicle.
Affects Vehicles with Air Suspension
- Place vehicle on hoist. Refer to => [ Positioning Vehicle on Hoist and Wheels ] Positioning Vehicle on Hoist and Wheels.
- Perform system vent using vehicle diagnostic tester. Refer to => [ System, Venting or Filling ] System, Venting or Filling.
Applies to All
- Remove the front wheels.
- Remove noise insulation.
- Remove the left front wheel housing liner.
- Remove coolant line retaining clamp nuts and bolts - arrows -.
• With connectors removed, coolant lines may be laid aside slightly in order to position (10 - 222 A /19) on the longitudinal members.
- Support engine entirely with engine support bridge.
• Support 3.6L FSI engine completely with engine support bridge
• Support the 3.0L TFSI engine completely with engine support bridge.
• Support 4.2L FSI engine completely with engine support bridge
• Support 3.0L TDI engine completely with engine support bridge
Affects Vehicles with 3.6L FSI Engine
- Remove bolt - 1 -.
• Ignore - 2 -.
- Attach the (2024 A /2) with an M8 x 35 bolt - 1 -.
- Mount the (10 - 222 A) , the (10 - 222 A /22) and the (T40091/3) on the fender bolting edges.
- Attach the parts from the (T40091) and from the (T40093) as illustrated.
• Mount the adapter (T40093/3) to the notches on the longitudinal member. Push the left refrigerant lines to the side and out of the way.
- Push the support (T40091/2) with both slides (T40093/5) into both mounts (T40093/4).
- Install the long spindles from the (10 - 222 A) and engage the hooks to the front engine lifting eye and to the (2024 A /2).
Loose parts on the engine support bridge can cause serious personal injury.
• Secure the (T40091/2) with the connector pins and splints (T40093/4).
- Tension engine by tightening 2 spindles evenly.
Affects Vehicles with 4.2L FSI Engine
- Remove rear engine cover - arrows -.
- Remove front engine cover - arrows -.
- Remove left and right air filter housing.
- Position (10-222 A) with (10-222 A/22) and connectors (T40091/3) on the bolted fender edges.
- Install additional (10-222 A) parts as shown in illustration. Also place supports (10 - 222 A /19) on notches on longitudinal members.
• Mount the adapter (10 - 222 A /19) to the notches on the longitudinal member. Push the left refrigerant lines to the side and out of the way.
- Engage hooks on both short spindles (10 - 222 A /10) at rear engine lifting eyes.
- Slide (T40091/2) with both slides (T40093/5) in both mounts (T40093/4).
- Install long spindles from (10-222 A) and engage spindle hooks at both front engine lifting eyes.
Secure (T40091/2) with connector pins and (T40093/4).
- Tension engine by tightening 4 spindles evenly.
Affects Vehicles with 3.0L TDI Engine
- Carefully remove engine cover from 4 retaining pins in succession - arrows -.
- Remove the air filter housing.
- Remove air guide hose - arrows -.
- Remove ribbed belt.
- Remove ribbed belt tensioner.
- Install (T10014) in the ribbed belt tensioner securing hole.
- Position (10-222 A) with (T40091/3) and 2 spindles on bolted fender edges.
• Spindles are at front.
- Engage both spindles at rear engine lifting eyes.
- Install additional (10-222 A) parts as shown in illustration. Also place supports (10 - 222 A /19) on notches on longitudinal members.
• Mount the (10 - 222 A /19) to the notches on the longitudinal member. Push the left refrigerant lines to the side and out of the way.
- Slide (T40091/2) with slide (T40093/5) into both connectors (T40093/4).
Secure (T40091/2) with connector pins and (T40093/4).
- Remove (2024 A) eyes.
- Insert pins - 1 - in the center engine sling eye and secure with a splint.
- Engage engine sling pins at front engine support bridge spindle.
- Install bracket (2024 A/1) on the left side of the engine sling.
- Engage (2024 A) at the right front engine lifting eye and at engine support (T10014).
Hooks and pins on engine sling must be securing with connectors - arrows -.
- Tension engine by tightening 3 spindles evenly.
Affects All Vehicles
- Remove both brackets with ABS speed sensor and brake wear indicator electrical lines at wheel bearing housing and disconnect connectors.
- Remove brake caliper and secure to the body so that the weight of the caliper does not stress or damage brake hose or brake line.
• The (3094) must not be secured on return hose in check valve area.
• The check valve is in the return hose between the cambers - A arrows - or between hose clamps - B arrows -.
Check Valve in Return Hose
- Clamp the intake hose and return line on the reservoir using (3094).
- Remove bracket for hydraulic lines - 1 -.
- Remove pressure line and return line - 2 - from steering gear.
- Free up the coolant hoses - arrow -.
- Disengage the power steering hydraulic line from the left brackets on the subframe.
- Remove the driveshaft from front final drive and tie it up.
- Remove - A - (if equipped) from the steering gear (2 bolts).
• Only remove the universal joint from the steering gear with front wheels in the straight ahead position.
• Do not change steering wheel position and steering gear position.
- Remove bolt - B - for the universal joint at steering gear and remove universal joint from steering gear.
- Disconnect the connector - arrow - at servotronic solenoid valve (N119).
- Remove nut from upper control arm and press arm off.
Prepare Scissor Lift Table
- Set up with (VAS 6131/10) as well as (VAS 6131/11) and (VAS 6131/13) as follows:
- Next, fasten support elements by hand onto the scissor lift table.
- Position (VAS 6131) horizontally.
• Note bubble level (level indicator) on mounting table.
- Guide scissor lift table under engine/transmission assembly.
- Attach mounting elements from (VAS 6131/10) and (VAS 6131/11) at the front of subframe as shown in illustration.
- Position supporting elements from (VAS 6131/13) on strut supports as shown in illustration.
- Attach mounting elements from (VAS 6131/10) at rear of subframe as shown in illustration.
- Rotate support element spindles upward enough so that all mounting pins contact mounting points.
- Attach the support element base plates to the (VAS 6131) and tighten to 20 Nm.
- Disconnect left and right connectors - 1 and 2 -.
- Subframe, securing, refer to => [ Subframe, Securing ] Description and Operation
- Remove bolts - 4 -.
- Lower subframe approximately 50 mm and carefully remove breather line - A - from front final drive.
- Unclip power steering line from the subframe and free it up.
- Now, slowly let down the subframe while constantly observing for freedom of movement.
Installing
Installation is the reverse of removal, with special attention to the following:
Tightening specifications, refer to => [ Subframe, Stabilizer Bar and Coupling Rod Overview ] Front Axle Overview
Tightening specifications, refer to => [ Coil Spring Suspension Strut, Upper Control Arm, Mounting Bracket and Level Control System Sensor Overview ] Front Axle Overview
Tightening specifications, refer to => [ Steering Gear Overview ] Steering Gear Overview
- Tighten the driveshaft.
- On vehicles with air suspension, position vehicle on wheels. Refer to => [ Positioning Vehicle on Hoist and Wheels ] Positioning Vehicle on Hoist and Wheels.
- Tighten the wheels.
- Bleed the steering system. Refer to => [ Steering System, Bleeding after Reinstalling ] Service and Repair.
- Check the power steering fluid level. Refer to => [ Power Steering, Checking Hydraulic Oil Level ] Power Steering, Checking Hydraulic Oil Level.
- Check the steering system for leaks. Refer to => [ Steering System, Checking for Leaks ] Steering System, Checking For Leaks.