Ohlins Shock Absorber for Renault Megane R.S. N4, TPXTTX44 RER XL52 Manual
Ohlins TPXTTX44 RER XL52 Design and Functioning
Congratulations on choosing the Öhlins TPX/ TX44 Rally shock absorber - the most unique and powerful shock absorber available today. The TPX44 in the front is a twin piston type shock absorber whereas the TTX44 in the rear is a twin tube type. The TPX44 is three way adjusted, high and low speed compression adjuster and rebound. The TTX44 is four way adjusted, it has the high and low speed compression adjuster and due to its design it features a main rebound adjuster and a fine tune adjuster. Both shock absorbers are equipped with the new updated Progressive Damping System (PDS).
The TPX/ TTX44 shock absorber design is the culmination of two decades of Öhlins successful participation in World Championship events.
The TPX/ TTX44 shock absorbers are designed to handle the demanding damping characteristics needed for all types of roads on which the car is aimed to compete on. For best performance, the shock absorber must be adjusted to different conditions; for the smooth and fast tarmac roads seen in some rallies to the more bumpy and twist seen in others.
The Öhlins TPX/ TTX44 features patent pending concept with a unique design, that allows for the gas pressure to always back-up the lowpressure side of the piston to keep pressure at a controlled level. Both concepts enable totally separated adjusters for compression and rebound damping. The temperature stability is maintained by using a flow restriction design in the bleed valves that create a turbulent flow at very low piston velocities. Also, materials with different thermal expansion rates are used to compensate for the viscosity change of the fluid caused by changes in temperature.
The Öhlins shim system offers infinite combinations of shim stacks with a wide spectrum of different character using only one piston. The whole system is pressurized by nitrogen gas behind a floating piston to ensure separation of gas and fluid.
The Öhlins TPX/ TTX44 shock absorbers are racer friendly shock absorbers, easy to set up, dial in and rebuild. Support is always available from the Öhlins distributors worldwide.
Ohlins TPXTTX44 RER XL52 Spring Preload
When adjusting the spring preload you move the spring seat. This will lower or raise the vehicle ride height. The ride height is important for the behavior of your vehicle.
Set the Spring Preload
Set the Spring Preload TPX Shock Absorber
- Use two C-spanners to undo the lock nut.
- Turn the spring platform to the desired position.
- After adjusting, lock the lock nut.
Set the Spring Preload TTX Shock Absorber
- Unlock the screw on the spring platform clamp.
- Use a C-spanner to adjust the platform to the desired position.
- Tighten the screw on the spring platform clamp.
Ohlins TPXTTX44 RER XL52 Compression and Rebound
Compression and Rebound Damping
Compression damping controls the energy absorption when the shock absorber is being compressed, thus controls how easy the shock absorber compresses when you hit a bump. Rebound damping controls the energy absorption when the shock absorber is being extended and controls how fast the shock absorber returns to its normal position after being compressed.
Compression Damping Adjuster
Low speed compression is mainly used to control chassis movements and response but it also affects the traction. It affects how the car behaves during breaking, turn in and acceleration. Less low speed compression gives more chassis movement but in many cases it can improve traction and grip. Therefore it is possible to balance the car by adjusting the low speed compression. High speed compression mainly affects how the car absorbs bumps and jumps. In rougher conditions or with a lot of jumps more high speed damping is often necessary to control the big chassis movements.
Rebound Damping Adjuster
Rebound adjuster affects chassis movement in a similar way as the low speed compression but has even more influence on traction. Use this adjuster to control chassis movements over crests or after jumps. More rebound gives less movement and better stability but too much will cause a loss of traction. It is therefore a powerful balance tool together with the low speed compression adjuster. For slippery conditions when grip levels are low, a softer set up on both rebound and low speed compression is a way to gain more traction.
Ohlins TPXTTX44 RER XL52 Adjust Rebound
Rebound Damping Adjuster
TPX44 Shock Absorber
To adjust rebound damping:
- Use a long 3 mm allen key or tool 01743-01 (delivered with the product).
- Turn the adjuster clockwise to fully closed position (position zero [0]).
- Turn counter clockwise to set the adjuster to recommended number of clicks (see Recommended Set Up in this manual).
- If you want to change setting, adjust in steps of 2-3 clicks at a time.
TTX44 Shock Absorber
The TTX44 has two rebound adjusters due to its unique design of twin tube layout and temperature stability valve design. The adjuster in the shaft end eye is the main adjuster and the one in the cylinder head is the fine tuning.
To adjust rebound damping:
- Use a 3 mm allen key or tool 01822-02 (delivered with the product).
- Turn the adjuster clockwise to fully closed position (position zero [0]).
- Turn counter clockwise to set the adjuster to recommended number of clicks (see Recommended Set Up in this manual).
- If you want to change setting, adjust in steps of 2-3 clicks at a time (both main and fine tune).
Useful adjustment range
main 5-30 clicks
fine 2-15 clicks
Ohlins TPXTTX44 RER XL52 Adjust Compression
Compression Damping Adjuster (TPX/TTX)
To adjust:
- High speed compression adjuster; Use a 12 mm wrench Low speed compression adjuster; Use a 3 mm Allen key
- Turn the adjuster clockwise to fully closed position (position zero [0]).
- Turn counter clockwise to set the adjuster to recommended number of clicks (see Recommended Set up).
- If you want to change setting, High speed compression; adjust in steps of 3-5 clicks to fine tune the set up. Low speed compression; adjust in steps of 2-3 clicks at a time.
Useful adjustment range
low speed 2-40 clicks
high speed 0-50 clicks
Ohlins TPXTTX44 RER XL52 Adjustment and Setting Up
Recommended Set up
At delivery the dampers are set according to the following;
RER 1- and 2L52
Low speed compression 10 clicks
High speed compression 20 clicks
Rebound 10 clicks
Spring (part no 06774-23) 80 N/mm
RER 6L52
Low speed compression 24 clicks
High speed compression 27 clicks
Main rebound 12 clicks
Fine tune rebound 6 clicks
Spring (part no 06320-19) 70 N/mm
Spring set-up
A number of springs are available to suit all different conditions and driving styles. See below a list of recommended springs (stiffness and part number).
Spring list
RER 1- and 2L52
70 N/mm, 06774-19
75 N/mm, 06774-21
80 N/mm, 06774-23 (std)
85 N/mm, 06774-25
90 N/mm, 06774-27
RER 6L52
60 N/mm, 06320-14
66 N/mm, 06320-17
70 N/mm, 06320-19 (std)
75 N/mm, 06320-21
80 N/mm, 06320-24
Making adjustments
Suspension settings depend on your vehicle’s weight, your driving style, road conditions etc. If you are not happy with our recommended settings, here are a few guidelines and ground rules how to make adjustments. To make improvements, it is important to understand the function of the shock absorbers and through testing learn how they affect the handling of your vehicle.
When making adjustments
- Take notes, make the adjustments in small steps (2-3 at a time) and stay within the recommended adjustment range.
- When you think you have made an improvement, go back to what you started with and double check to be sure.
- Pay attention to changes in conditions like tires or temperature, etc. In general, compression damping changes should be used to influence the vehicle’s response and balance while rebound damping changes should be used to influence traction and stability.
- When you need more damping force in the front, first try to increase compression damping and use as little rebound damping as possible. This usually means that you improve response and handling performance but keep traction. For the rear, more compression reduces exit understeer and more rear rebound can help turn in and first part of the corner.
Ohlins TPXTTX44 RER XL52 Inspection and Maintenance
Preventive maintenance and regular inspection reduces the risk of functional disturbance. If there is any need for additional service, please contact an authorized Öhlins Service Centre.
Ohlins TPXTTX44 RER XL52 Cleaning
Clean the shock absorber externally with a soft detergent. Use compressed air. Be careful that all dirt is removed. Lift the bump rubber and clean the area below. Keep the shock absorber clean and spray it with oil (WD40, CRC 5-56 or equivalent) after washing. Wipe off excessive oil with a cloth.
Ohlins TPXTTX44 RER XL52 Inspection points - Normal use
- Check ball joints/ brackets for possible excessive play or stiction.
- Check the piston shaft for damage that can cause leakage.
- Check the shock absorber body for external damage.
- Check the external reservoir for damage that can restrict the floating piston from moving freely.
- Make sure that the reservoir is protected against stone chip.
- Check the attachment of the shock absorber to the vehicle.
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