How to center steering rack

[Rice86]

Car - AE86

motor - 20v

use - street purpose

problem - wheel alignment, need to know how to make the rack center, im using standard ADM manual rack with and only modification is the JDM power steering arms

occurs/started when - when i pulled the whole car apart into pieces and put it all back in

personal situation - i need to know how to make the rack center, so i can atleast try to make the wheel alignment straight so i can drive it reasonably to the shop to get the wheel alignment done by a pro

google didnt help much and did a search with RACK on the forum and only got details about racks, not on how to make them center...

[ke70dave]

if all you are trying to do is good enough wheel alignment to get it to the shop, im not entirely sure that centering the rack perfectly is really needed.

ive done the following to get an alright wheel alignment quite a few times, in fact ive been driving on one of my wheel alignments for a while now...waitin to get new parts before i get a proper alignment.

-get all the parts into your car, rack, steering components etc etc.
-when you are assembling, try and assmeble everything pretty close, like when you put the tie rod ends on, line both the wheels up with the guard, just by eye so they are within a reasonable amount. and also try and screw the tie rod ends on the same amount on both sides, dont wind one all the way on, while leave the other one hanging on by only a few threads. you can do this fairly easily by just measuring the number of threads that are left on the rack end
-its best to do the folloing with both wheels on the ground, but since our cars are pretty low, put the front wheels on blocks of wood or wheel stands. so that your wheels sit in the "normal" position witih all the suspension loaded.
-now find yourself 2 lengths of rod or stick, i used 2 x 1m rulers when i do this.
-now the goal here is to get the distance between the front of the tyres the same as the distance between the rear of the tyres. this is done by using the 2 x 1m rulers, sliding them against each other making an extra long ruler, and when you have the length you just hold onto them in the middle.
-so say you start with the front wheels, line up your 2 rulers and get the distance between the front of the wheels, then hold onto it and compare it to the backs of the wheels. then you just have to make adjustments to the tie rod ends to get this the same. make the same adjustments on both tie rod ends the same mount, i usually measure it by how many "turns" of the rack end i do.
-so you bascially just keep comparing the distance between the front of the wheels, and backs of the wheels and keep making changes untill you have them the same.
-also note that with the geometry present small changes in the tie rod ends are exadurated at the tyre. so you wont need to change much if you set everything up pretty close.

and thats pretty much how to get your toe almost perfect, last time i did this i think the wheel alignemnt shop said i had 0.5mm of toe in or something, which isnt bad for a back yard job.

you can do a simliar thing with camber by using a square on the ground, and then just measuring how far the top of the wheel is off the vertical line. you cant do as good a job as the toe, but you can get it pretty close.

ive not figured out how to easily get castor the same, other than just making sure yo have about the same amount of thread showing on the castor adjustment rod thing.

[Rice86]

this is so printed on hard copy for use 2morow, cheers man appreciate quick replys =]

[Vizz]

After bolting a steering rack back in and before reconnecting the steering column to the pinion, I centered a rack by sliding it entirely to one side, then counting the number of rotations done by the pinion to slowly slide the rack to the other end. Helps to have a paint pen dot on the pinion so its easier to watch. Then with the rack fully to one side start sliding it to other side but stop after you count half of the pinion rotations you noticed when going from side to side. This should put you in the center of the rack and so you can reconnect the steering column with the steering wheel located in the normal straight driving position.

This worked for me but it was not on a Toyota, it seemed reasonable though.

[Rice86]

that makes a lot of sense too lol...also printed as hard copy for use...cheers man

[takai]

Yeah, just wind all the way in one direction, and then back to the other side, count the turns. Then turn it back half again.

Rinse and repeat a few times for accuracy.

[Skylar]

It's like 150mm from rack end to rack housing at full steer one way. So I made sure both ends had 75mm rack end to housing.

Same shit as what everyone's saying but I found it easier to work in mm's instead of turns.

[Rice86]

nice, this should be Tech Article as these are very simple a valid methods to get this done