How to achive 90 degrees line alignment rear wheel?

exactly what do you mean by this ?
are you saying that when the bike is vertical that the rear wheel is at an angle to the road and not vertical as is the frame
If that is the case the rear suspension swing mounts are worn out , frame is bent for the rear wheel or if the wheel only has one swing arm , that is bent

If you're talking about the alignment of the steering wheel when you're driving in a straight line, that's usually handled when you get a wheel alignment. Not normally attempted by weekend mechanics (like me).

the return to the center on it's own is a result of the wheel alignment castor setting
if it set at zero or minus setting ( -1 degree) it has no action requiring it to return to center
To explain how it works --- the angle at which the king pin is set back ( positive degree) lowers the car
when turning a circle , the car is lifted up and loads up the king pin
when you let the wheel go that weight tries to fall down and that is the return to center position action
so to fix that problem , have a wheel alignment done and set at positive degrees ( normally around 1 1/2 degrees)
next problem is when you set with the wheels straight ahead there is no allowance for the camber of the road ( used to allow water run off in the rain) that means that if you position the wheel straight ahead when on flat ground then when driving down the road you will have the wheel slightly off center to allow for the car trying to run off the road from the road camber
it could also mean that if you have had suspension or steering work done that the steering was not centralized when the tie rod ends were adjusted for toe in adjustment and so the box /rack is now set slightly one way
it could also mean that the rear end is out of alignment and the vehicle is running sideways down the road ( crabbing)
the fix is to find yourself an accredited wheel alignment shop and have an alignment done properly starting by aligning the rear wheels first and then the front many will say not necessary but I can assure you that it is vital for tire wear and vehicle handling and if they don't want to do the job properly go somewhere else

This is just a free chat room

We have no info like that

We are at home & use the site-- the same as you do

castor angle 1/2 to 11/2 degrees
camber 0 to 1degrees
toe in 1/8 to 1/4
As it has to be done at a wheel alignment shop they will know the best settings. Make sure that they do the alignment on the rear first as it affects the front alignment

Look under the drivers side between the front and rear wheels located on the undercarriage...fuel line turned 90 degrees then continues toward gas tank insert. Hope this helps.

Before making wheel alignment adjustment, perform the following checks:

1. Tires should be equal in size and runout must not be excessive. Tires and wheels should be in balance, and inflated to manufacturer's specifications.


2. Wheel bearings must be properly adjusted. Steering linkage and suspension must not have excessive looseness. Check for wear in tie rod ends and ball joints.
3. Steering gear box must not have excessive play. Check and adjust to manufacturer's specifications.
4. Vehicle must be at curb height with full fuel load and spare tire in vehicle. No extra load should be on vehicle.
5. Vehicle must be level with floor and with suspension settled. Jounce front and rear of vehicle several times and allow it to settle to normal curb height.
6. If steering wheel is not centered with front wheels in straight-ahead position, correct by shortening one tie rod adjusting sleeve and lengthening opposite sleeve equal amounts.
7. Ensure wheel lug nuts are tightened to torque specifications

Ride Height Adjustment

Before adjusting alignment, check riding height. Riding height must be checked with vehicle on level floor and tires properly inflated. Passenger and luggage compartments must be unloaded. Bounce vehicle several times, and allow suspension to settle. Visually inspect vehicle from front to rear and from side to side for signs of abnormal height.
Measure riding height. See figure. Riding height between left and right sides of vehicle should vary less than 1′ (25.4 mm). If riding height is not within specification, check suspension components and repair or replace them as necessary.
Wheel Alignment Procedures

Honda recommends using commercially available computerized 4-wheel alignment equipment. Follow equipment manufacturer instructions to obtain vehicle alignment settings. Use following procedures for necessary adjustments.
Civic Camber Adjustment
Compare camber settings with vehicle manufacturer recommendations. If camber is incorrect, check for bent or damaged front suspension components. Replace faulty components. Recheck camber.
Civic Caster Adjustment
DO NOT use more than 2 shims. If more than 2 shims are required to adjust caster angle, check for bent or damaged suspension components.
Compare caster settings with vehicle manufacturer recommendations. If caster is incorrect, check for bent or damaged front suspension components. Replace faulty components. Recheck caster.
Civic Toe-In Adjustment

1. Secure steering wheel in straight-ahead position. Measure front wheel toe-in. If adjustment is needed, loosen tie rod lock nuts. Turn both tie rods equally in the same direction until front wheels are in straight-ahead position and toe-in reading is correct. Tighten tie rod lock nuts. Reposition tie rod boots if twisted.
2. Ensure parking brake is released. Check rear wheel toe-in. If adjustment is needed, hold adjusting bolt on rear compensator arm and loosen lock nut. See figure. Adjust rear toe-in by sliding rear control arm until rear toe-in is correct. Install NEW lock nut, and tighten it while holding adjusting bolt.

Wheel Alignment Specifications

• Camber - Measurement in degrees.
  • Front: 0 (range -1 to 1)
  • Rear: 0.33 (range -1.33 to 0.67)
• Caster - Measurement in degrees.
  • 1.17 (range 0.17 to 2.17)
• Toe-In - Measurement in inches (mm).
  • Front: -0 (0)
  • Rear: 0.08 (2.0)
• Toe-In - Measurement in degrees.
  • Front: 0.00 (range - 0.16 to 0.16)
• Toe-Out On Turns - Measurement in degrees.
  • Inner: 41.00
  • Outer: 33.50

Torque Specifications Ft. Lbs (N.m)

• Rear Control Arm Adjusting Bolt: 48 (65)
• Spindle Nut: 136 (185)
• Tie Rod Lock Nut: 41 (55)
• Wheel Lug Nuts: 80 (108)

hope this helps you out.

You need to ask them whether they are talking about 1 front wheel out of alignment to the frame or if 1 front tire is out of alignment to the rear wheels. Or are both front tires out of alignment in 1 direction?

You can sometimes have worn rear mounting bushings for the springs allowing the rear differential tube to canter to one side. This would be similar to the "dogwalk" condition that has the rear running off center to the direction of travel.

The best thing would be to go to a frame shop. The other conditions can mean the frame is tweaked or the rear tube is bent. You could try pulling the rear spring bolts, lay each one on a flat surface and turn the bolt while shining a flashlight under it. A slight bow in the bolt will allow more light to pass under the bolt. Then you will know if the bolt is slightly bent.

Once you know the problem, then you can do something about fixing it. If the right side front is +6 degrees off and the left side is -6 degrees off, the frame is curled to the right. A frame shop has the equipment to make bending adjustments. An alignment shop can only bolt on new straight parts the same as you can.

I hope I have helped give you some ideas; the Alignment shop should have told you more about your problem than its 6 degrees off. They would still have your business for the final Alignment after you worked on the truck, because an Alignment would still be needed.

New bolts ;
1. tighten 190 Nm with wheel off the ground.
2. lower car to ground, tighten further 180 degrees
3. tighten further 90 degrees.

have a look at the front wishbone rear bushes, these can pop out