Mud-club

Vehicle & Technical => Defender => Topic started by: turtle on May 10, 2005, 21:11:52

Title: Preload
Post by: turtle on May 10, 2005, 21:11:52

Might be a silly question but could someone explain what the preload is and how to correct it?

Title: Preload
Post by: Guy90 on May 10, 2005, 21:36:35

Phil,

Do you mean swivel pre load? You need a spring balance and some shims and fiddle away until it is within tolerance. You pull on the spring balance attached to the bit where the ball joint goes.

I have a spring balance if you need. Never tried this job I have to say but the wrong pre load affects the steering etc

Title: Preload
Post by: muddyweb on May 10, 2005, 22:06:22

The swivel housing should have a certain amount of inherant resistance to turning when properly adjusted.  This is its 'preload'.  It helps to reduce shimmy in the steering by having it too loose.

As Guy says, you need to pop the steering linkages and front wheels off and with the vehicle *level* put a spring balance on where the steering linkage attaches.  

By pulling on the spring balance, you should get an even resistance as the swivel moves..  the balance will show the preload.

It is adjusting by adding and removing shims under the top pin.

Before you adjust it all, have a good feel of the movement of the swivel to make sure there is no notchiness or odd resistance.  This would point to a failing swivel bearing or worn top pin.

The actual preload figure escapes me off the top of my head... but a quick search should turn it up.

Title: Preload
Post by: turtle on May 10, 2005, 22:34:09

Cheers Guys thats helps, I can now at least say I know what people are on about when they mention the preload :)

After that discription, could this be the cause of my vibration ?

Not a job I think I can do, but would it be worth getting it checked?

Title: Preload
Post by: ibexman on May 10, 2005, 23:19:51

just to add, you check the preload with the swivel oil seal removed.  personally i've never bothered with the spring balance technique, do it by feel.
dom

Title: Preload
Post by: karloss on May 11, 2005, 23:19:12

Quote from: "ibexman"

i've never bothered with the spring balance technique, do it by feel.
dom

Glad it's not just me. :wink:

Title: Preload
Post by: muddyweb on May 11, 2005, 23:21:08

I didn't used to... then I stuck a balance on it and realised how far out I'd been getting it.

Now, for the sake of 10 paces across to the tool chest, I use the balance ;-)

Title: Preload
Post by: ibexman on May 14, 2005, 20:22:10

perhaps i ought to invest in one :(
dom