Some degree of torque steer to the right may normally be experienced during a heavy throttle application on some front wheel drive vehicles which do not have equal length drive axles. This is due to the right drive axle being longer than the left axle and an associated difference in an axle angle. Vehicles with an intermediate shaft assemblies have almost equal length axles.
A difference in axle length results in more torque toe-in effect to the left front wheel. This condition can be noticed when accelerating from a standing start or at lower speeds. A simple measurement to determine the degree of torque steer is to place a small piece of tape at the top center of the steering wheel. Drive the vehicle and note the inches of steering wheel deflection required to steer the vehicle straight under heavy acceleration. A comparison of like vehicles will then determine if a particular vehicle has a greater than normal degree of torque steer. The following factors may cause the torque steer to be more apparent on a particular vehicle:
| • | A large difference in the right and left front tire pressure. |
| • | A slightly smaller diameter tire on the right front will increase a right torque lead. |
| Inspect the front for a difference in brand, construction or size. If the tires appear similar, change the front tires side to side and re-set the vehicle. Tire and wheel assemblies have the most significant effect on the torque steer correction. |
| • | Any looseness in the control arm bushings, tie rod assemblies, or steering gear mounting which permits a front wheel to pull forward and toe-in under torque more than the opposite side. A loose suspension component may also result in an opposite lead deceleration. |
| • | A high front trim height which would increase the drive angle axle. |
| • | A binding or tight drive axle joint. |
| A tight joint or high front trim height may also exhibit a wobble condition between 24 and 48 km/h (15 and 30 mph). |
| • | An incorrect, worn or loose engine mounts causes adverse drive axle angles. |
| • | An unequal Engine/Transmission height from the left side to the right side of the vehicle. |
| Determine the measuring points. If the difference from side to side is more than 6 mm (17/64 in), change the trim heights by installing a stronger spring in the side which is lower, or a weaker spring in the side which is shorter than the specified Z height. Do not shim the engine mounts. Shimming the engine mounts may cause other symptoms. |
| • | On occasion, the side to side trim height differences may be the result of a defective stabilizer shaft. Disconnect the stabilizer links. Measure the trim heights again after the vehicle has been settled, driven a short distance. Replace the stabilizer shaft, if the side to side difference is corrected. Do not change the stabilizer shaft however, if there is no change in the trim height. A trim height difference of more than 6 mm (17/64 in), indicates a bent stabilizer shaft, attaching links or a suspension component that may need replacement. |
The following conditions affect the vehicle handling and/or a constant right or left lead separate from torque steer causes. The existence of one or more of these conditions may compound a torque steer complaint.
| • | An incorrect front-wheel alignment or a rear-wheel alignment condition which would cause the vehicle to not track straight. A difference in the front wheel to the rear wheel measurement compared side to side may indicate a dog track condition or one front wheel ahead of the other due to a misalignment or other condition. A substantial caster difference is an indication of misalignment or other condition. Front-wheel caster should be equal or within specifications and camber may be biased slightly to offset a lead condition. |
| • | Suspension support misalignment. Refer to Alignment Checking in Frame and Underbody which lists measurement points in order to determine proper underbody alignment. |
| Front suspension damage such as a bent strut. |
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 |
Does the vehicle lead/pull with the transmission in neutral? | -- | System OK | |||||||||
2 | Refer to Vehicle Leads/Pulls . Does the vehicle lead/pull under engine torque? | -- | System OK | |||||||||
3 | Swap the front tire and wheel assemblies. Road test the vehicle. Does the vehicle lead/pull under engine torque? | -- | System OK | |||||||||
4 | Road test the vehicle. Is the torque steer in the opposite direction? | -- | ||||||||||
5 | Swap the left front tire and wheel assembly with the left rear tire and wheel assembly. Road test the vehicle. Does the vehicle still torque steer? | -- | ||||||||||
6 | Swap the right front tire and wheel assembly with the right rear tire and wheel assembly. Road test the vehicle. Does the vehicle still torque steer? | -- | System OK | |||||||||
7 | Position the tire and wheel assemblies to produce minimum torque steer before proceeding. Measure the vehicle's Z heights. Is the left to right difference more than 6 mm? | -- | ||||||||||
8 | Correct the Z heights. Reset the camber and toe (toe only on the J and H Cars). Road test the vehicle. Does the vehicle still torque steer? | -- | System OK | |||||||||
9 | Measure the vehicle's Z heights. Is the left to right difference less than 6 mm? | -- | System OK | |||||||||
10 | Measure the trans height. Is the left to right difference more than 6 mm? | -- | ||||||||||
11 | Correct the height difference by replacing the engine transmission mount. Road test the vehicle. Does the vehicle still torque steer? | -- | ||||||||||
12 | Measure the trans height. Is the left to right difference more than 6 mm? | -- | System OK | |||||||||
13 | Perform a wheel alignment on the vehicle. Does the vehicle torque steer left? | -- | ||||||||||
14 | Set the camber -0.5° left and +0.5° right. Road test the vehicle. Does the vehicle still torque steer left? | -- | System OK | |||||||||
15 | Set the camber -1.0° left and +1.0° right. Road test the vehicle. Does the vehicle still torque steer left? | -- | System OK | |||||||||
16 | Set the camber +0.5° left and -0.5° right. Road test the vehicle. Does the vehicle still torque steer right? | -- | System OK | |||||||||
17 | Set the camber -1.0° left and +1.0° right. Does the vehicle still torque lead? | -- | -- | System OK | ||||||||
18 | Set the camber +1.0° left and -1.0° right. Does the vehicle still torque lead? | -- | -- | System OK |
