Adjusting steering gear pre-tension

[kilou]

Hi,

the steering of my 240'000km Volvo S40 feels rather loose especially at high speed. I've yet the whole front suspension ie dampers/shocks, strut mounts, antiroll bar drop links, front control arms with balljoint and I will soon change both inner and outer tie rod ends. However it seems that there is some play in the steering rack itself.

I have a mechanical DVD from Volvo that explains how to adjust the steering gear pre-tension on pinion. Do you know what it means?

It is said that to perform this adjustment, the steering gear must be removed however I'd like to know if this step is really essential or if it is possible to do it with the rack still on the car just by disconnecting the steering column from the rack pinion shaft?

See the image below for the steps mentionned on the Volvo DVD:
http://www.brickboard.com/IMAGELIB/images/4406.gif

Do you understand what this adjustment will do and whether it can be done with the rack still on the car or not?

Thanks

 

[JohnBrowning]

It adjusts how much static load is on the pinion and rack gears it is also used on conventional ball and joint type setup. If you feel that the wheel is sloppy and or the self centering nature is a bit off then your preload is either too little or too much. As the gear wear the amount of preload set at the factory deminish's and you end up with slopp and you will find that the wheel will sometimes go past center when it self centers as you turn.

On most vechiles that have the ability to be adjusted you have a set screw and a locking nut kind of like the valve follower adjutment set up on Toyota cam followers. They should give you a specific preload number. With the unit out of the car you can do it properly.

If you do not want to do it properly it has been my experince that you can safely do it with the unit in car. I have found on most models that you can make 1/8 of a turn adjustents and then test drive to determine when it is close to write. It is better to under tighten then over tighten.

If you havenever done one it is often better to leave it alone as most people will end up voer pre-loading their steering gear box. If you have done a bunch of them before you develop a feel for it like anything.

You might see what a local Tech. would want to do it! You are going to have to get an alingment after you replace the other parts you might as well git it adjusted at the same time.

 

[kilou]

Thanks for the comment John. I've found on the web that the preload adjustment on rack and pinion system is rather tricky since this is done to accomodate for central wear in the steering gear. The problem is that once the adjustment is performed to correct the loosiness due to central wear, the gear system is no more correctly adjusted when the steering is turned and it may become overtightened and thus bind the rack if the steering is steered too much. This doesn't sound too good

 

[cryptokid]

im going to do this on my piece of crap ford. my dad told me to tighten the screw untill i feel resistance and then back off untill the resistance stops. at this point i should tighten the locking nut. i guess ill just screw around with it and see what happens.

 

[kilou]

Do you know where is the locknut I should first tighten to 15Nm prior to adjusting the preload (see diagram on the link in the 1st post)? It is strange that this procedure requires removal of the complete rack. It sounds it should be possible to achieve the same simply by disconnecting the steering column from the pinion shaft and disconnecting the outer tie rods from the swivels....no?