PS Steering judder pt3

[SwannyUK]

Originally Posted by Laird Scooby

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.

Haha! Sorry I see! I did wonder! I'll take a look.

[SwannyUK]

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

When I changed the PS pump, I bled the system and did full turns lock to lock loads of times, and it still returns.

Originally Posted by Laird Scooby

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.

I did wonder if it was old seals within the rack causing blow-by and causing it.

I'm pleasantly surprised that I dont get any vibration when breaking, i recently had this on my E61 BMW and was worn track rod ends.

[Jimarilo]

[QUOTE=Laird Scooby;2862624]

Spaceship bushes indeed lol

[940volvoman]

Turns out I now have some juddering on the steering on my mid engine mitsubishi van.On startup it sounds like a cat screaming his lungs out and the engine speeds up slightly when the screaming stops.The power steering is then ok.Im hoping this is just the belt perishing therefore not allowing the pump to work..I'll lift up the seats at the weekend to investigate....

[Laird Scooby]

Originally Posted by 940volvoman

Turns out I now have some juddering on the steering on my mid engine mitsubishi van.On startup it sounds like a cat screaming his lungs out and the engine speeds up slightly when the screaming stops.The power steering is then ok.Im hoping this is just the belt perishing therefore not allowing the pump to work..I'll lift up the seats at the weekend to investigate....

Next doors cat crawled in and fell asleep on the engine Shaun, when you started, it was chewed up by the PAS belt hence the screaming and eventually the PAS worked once the blood and guts had worn off the belt and pulleys!

More seriously (and less harmfully to the feline population), it sounds simply like the belt is slack and/or the system is low on fluid.
Normally on Japanese stuff, the PAS works regardless and any faults are either seriously major like catastrophic failure of the pimp or a burst seal in the rack. As neither of those seem to be a possibility here, some simple maintenance should fix things.

[940volvoman]

It must be catastrophic failure of the pimp,Dave!! (lol)

[Laird Scooby]

Originally Posted by 940volvoman

It must be catastrophic failure of the pimp,Dave!! (lol)

Catastrophic failure of my typing too Shaun!

[SwannyUK]

Originally Posted by SwannyUK

Haha! Sorry I see! I did wonder! I'll take a look.

I took a look, and it looks a little dirty, but I need to have a furkle while the engine's not super hot, see if there's much play I suppose;

[Laird Scooby]

Originally Posted by SwannyUK

I took a look, and it looks a little dirty, but I need to have a furkle while the engine's not super hot, see if there's much play I suppose;

That's the one, yeah, if it's siezed there won't be any play in it. Can't remember if i suggested it already but a 50/50 mix of acetone/Carlube ATF-U or NAPA MVA ATF, shake it well then brush it copiously on to the UJ. Wait for it to soak in the give it some exercise from lock to lock several times then repeat.
Keep the acetone/ATF mix sealed when not in use or the acetone will evaporate, it's a fantasstic penetrating fluid and once the acetone evaporates after penetrating, the ATF lubricates and helps prevent rust.

On a slightly different note, the seam where the inner wing joins the chassis member is starting to bubble with rust. Best caught early, wire brush it then use something like Jenolite or Kurust to convert the rust and then get some paint on it - Kurust is fairly liquid, apply it generously so it runs down between the inner wing and chassis member to bits you can't get at. It's a common place for all 7/9xx to rust but once prevented it should last a good few years more.

[360beast]

Originally Posted by Laird Scooby

That's the one, yeah, if it's siezed there won't be any play in it. Can't remember if i suggested it already but a 50/50 mix of acetone/Carlube ATF-U or NAPA MVA ATF, shake it well then brush it copiously on to the UJ. Wait for it to soak in the give it some exercise from lock to lock several times then repeat.
Keep the acetone/ATF mix sealed when not in use or the acetone will evaporate, it's a fantasstic penetrating fluid and once the acetone evaporates after penetrating, the ATF lubricates and helps prevent rust.

On a slightly different note, the seam where the inner wing joins the chassis member is starting to bubble with rust. Best caught early, wire brush it then use something like Jenolite or Kurust to convert the rust and then get some paint on it - Kurust is fairly liquid, apply it generously so it runs down between the inner wing and chassis member to bits you can't get at. It's a common place for all 7/9xx to rust but once prevented it should last a good few years more.

Looks like it is rusting below the bonnet release cable grommet too, a common rot spot that allows water in to the footwell.