PS Steering judder pt3

[SwannyUK]

Well, following my post regarding swapping the PS pump, and then regarding the tension of said PS belt, where I swapped for a Volvo one, I'm still getting judder.

I *think* the belt is a decent tension. I've adjusted, tightened the big bolt, and then slackened off the adjuster.

The judder is still there though - usually turning right, which is a pain because of roundabouts. I've found that the front tyre pressure needs to be spot on, and sometimes if you give it some beans into the corner, the weight on the outside wheel seems to stop the judder.

The next thing I was going to do was to swap the power steering rack with a refurbished one from ClassicSwede. Am I just grasping at straws now, or is it a possibility and old worn, rack might be the culprit?

[Forrest]

Have you got the fluid level correct? According to the user manual:

Power steering fluid

The fluid level should lie between the MIN and MAX marks on the dipstick.
Check fluid level with engine idling and after driving while the fluid still is hot. Wipe the reservoir clean.

I think I remember reading once that the correct level reading was obtained with the cap just resting on the reservoir rather than screwed fully down, but I cannot find any reference to that now.

Did you bleed air out of the system after you changed the pump? You have to turn from lock to lock a number of times with the cap off the reservoir to do this effectively.

Is the knocking definitely related to the power assistance? Worn track rod ends and universal joints can make the steering feel notchy.

[Laird Scooby]

Originally Posted by SwannyUK

Well, following my post regarding swapping the PS pump, and then regarding the tension of said PS belt, where I swapped for a Volvo one, I'm still getting judder.

I *think* the belt is a decent tension. I've adjusted, tightened the big bolt, and then slackened off the adjuster.

The judder is still there though - usually turning right, which is a pain because of roundabouts. I've found that the front tyre pressure needs to be spot on, and sometimes if you give it some beans into the corner, the weight on the outside wheel seems to stop the judder.

The next thing I was going to do was to swap the power steering rack with a refurbished one from ClassicSwede. Am I just grasping at straws now, or is it a possibility and old worn, rack might be the culprit?

Is the judder road-speed related or engine-speed related? The fact it disappears going through corners suggests a worn wheel bearing or perhaps track rod end or lower ball joint.
If you're going through a right hand bend and the judder reduces, it will be on the left of the car and vice versa because of weight transfer.

While it's nice firing the parts-cannon, it becomes an expensive hobby when chasing something like this, much better to spend time diagnosing and confirming the fault before spending £££££ on a problem that may or may not be related.

[J liddy]

I've had that problem turning while diving I'm sure mine was air in the system it cured its self it was annoying and I was giving up at one time I purged the system by removing the resivoir oil with a large syringe then new oil then driving then doing it again my car been running fine now for years

[940volvoman]

I'm wondering if it couldn't be the universal joint seized or seizing.Before I had mine replaced earlier this year I would get all sorts of weird symptoms,like juddering and not being able to turn the wheel suddenly and without warning,.It could be very scary at times.

Since I had it replaced those problems are gone.

While we are on the subject of thy p.s hydraulics,I had an inline filter sent over from the states to clean up any debris in the system and prevent any future damage by said debris when I had the rack replaced.

[Laird Scooby]

Originally Posted by 940volvoman

I'm wondering if it couldn't be the universal joint seized or seizing.Before I had mine replaced earlier this year I would get all sorts of weird symptoms,like juddering and not being able to turn the wheel suddenly and without warning,.It could be very scary at times.

Since I had it replaced those problems are gone.

While we are on the subject of thy p.s hydraulics,I had an inline filter sent over from the states to clean up any debris in the system and prevent any future damage by said debris when I had the rack replaced.

Raybestos Autofine for the filter? They're good kit, got one or two floating around for use on my ATF but it stays clean enough to have never needed to use it!

[SwannyUK]

Originally Posted by Forrest

Have you got the fluid level correct?

Yup, I've been keeping an eye on it and its at the correct level.

Originally Posted by Forrest

Did you bleed air out of the system after you changed the pump?

Yes - spent several hours bleeding it, and adjusting the belt tension etc.

Originally Posted by Forrest

Is the knocking definitely related to the power assistance? Worn track rod ends and universal joints can make the steering feel notchy.

Yes, its intermittent, both turning left and right, sometimes its fine, sometimes its not. If it were something more mechanical rather than hydraulic, then I'd expect it to be more consistant.

Originally Posted by Forrest

Is the knocking definitely related to the power assistance? Worn track rod ends and universal joints can make the steering feel notchy.

I do have a pair of new track rod ends I picked up on sale, those and the ARB drop links I expected to have to replace.

Originally Posted by Laird Scooby

Is the judder road-speed related or engine-speed related? The fact it disappears going through corners suggests a worn wheel bearing or perhaps track rod end or lower ball joint.
If you're going through a right hand bend and the judder reduces, it will be on the left of the car and vice versa because of weight transfer.

I've been trying corners at different road speeds and engine speeds and I can't get it to be consistent.

Originally Posted by Laird Scooby

While it's nice firing the parts-cannon, it becomes an expensive hobby when chasing something like this, much better to spend time diagnosing and confirming the fault before spending £££££ on a problem that may or may not be related.

I totally agree - I'd rather diagnose the issue than use the parts cannon approach!

Originally Posted by 940volvoman

I'm wondering if it couldn't be the universal joint seized or seizing.Before I had mine replaced earlier this year I would get all sorts of weird symptoms,like juddering and not being able to turn the wheel suddenly and without warning,.It could be very scary at times.

Since I had it replaced those problems are gone.

As in between the prop and the gearbox? Hadn't considered that at all.

[Laird Scooby]

Originally Posted by SwannyUK

As in between the prop and the gearbox? Hadn't considered that at all.

Not that one!

There is a UJ in the steering column between the bulkhead and rack, usually obscured by the turbo on turbo cars but more visible on n/asp cars. Less likely to fail on n/asp cars as the heat from the turbo cooks the lubricant out of the UJ on turbo cars and they seize and cause symptoms similar to what you've described.

If you make a 50/50 mix of synthetic ATF (Carlube ATF-U, NAPA MVA or similar) and acetone (nail varnish remover if you like), shake well then brush it on the top of the UJ, let it soak for a minute, turn the steering wheel 180deg then repeat, after it's had a goodsoaking from a few different turns etc, start the engine and work the steering lock to lock several time to help distribute the mix in the UJ, this might help the problem.
Keep the mix sealed when not in use and shake before each use, the acetone will separate and evaporate off if not sealed and as it separates, needs shaking before use. It's a fantastic penetrating fluid, makes WD40 look like water and works out cheaper than WD40 as well!

[Jimarilo]

I noticed juddering from my power steering on road test after fitting front brakes

Then realised that turning the front wheels without the engine running, ie. no power steering was the cause

The next time I did work on the front end, after starting the engine would turn the wheel from lock to lock which would cure the issue

The only other juddering was, when applying the brakes, which was worn tie rod bushes on the bottom arms, easy fix

[Laird Scooby]

Originally Posted by Jimarilo

I noticed juddering from my power steering on road test after fitting front brakes

Then realised that turning the front wheels without the engine running, ie. no power steering was the cause

The next time I did work on the front end, after starting the engine would turn the wheel from lock to lock which would cure the issue

The only other juddering was, when applying the brakes, which was worn tie rod bushes on the bottom arms, easy fix

You can turn the steering wheel with the engine off without a problem, the problem comes when the roadwheels are physically moved to change the direction they point withthe engine running or not. Seems it causes some sort of blow-by in the rack seals and puts air where it shouldn't be.
Had this many times after each MoT and takes anything from a day or two of normal use to a couple of weeks to resolve the problem.

As for the spaceship bushes, yes they will cause juddering when braking as will worn lower ball joint but they can also cause vibration at any speed too.