Steering: Pulsing/varying steering assistance

[AidanC]

I was travelling down a circular sliproad to join a motorway and noticed a possible issue with the steering. The angle of the bend was quite tight so the steering felt like it was under load. I was doing approx 40 mph/60 kmh. I noticed that the steering seemed to lose feel for a second or so every ten seconds. The car didn't change direction or wander in any way but it was quite disconcerting.

I recently had a four wheel alignment done (printout on post #4 of this thread https://www.volvoforums.org.uk/showthread.php?t=272399) so the alignment should be still ok. The level of fluid in the power steering reservoir is fine.

Has anyone noticed this issue on their car?

[MissSpentYouth]

Hi there,

This is a really common problem and is due to wear in the steering rack.

I am afraid you will need a new steering rack fitting, in rare cases you will also need to replace the pump as well but not very often.

regards Ben

[binty]

Could well be a rack problem.
I tried a power steering fluid change myself though and it cured it completely.
(Not very often I get lucky but I did).

Fluid should be green. Mine was brown. see picture.

2l of Volvo oil was plenty to give it a good flush through. (i would only use Volvo oil)

This is what I did.

Park front wheels on a couple of thick bin bags to help the wheels turn.
Lift the power steering reservoir off the water reservoir and tip out all the fluid then disconnect the return hose, (jubilee clip), and put it in a plastic bottle.
Either blank off the return inlet on the reservoir or get an assistant to press their finger over it.

Don't start the engine, (I did and it emptied the reservoir in a jiffy and I had to bleed air out of the system).

Fill the reservoir with new fluid and then turn the steering wheel from lock to lock repeatedly. Each time it will discharge some old fluid into the bottle and suck in some new fluid from the reservoir so keep an eye on the levels so you don't suck air in.

After about 10 or more turns the new fluid should be seen coming through the system. Just re connect and adjust the level.

This will not cure a failed rack, but it can help with a sticky one so may be worth a DIY try for £25 before splashing out on a rack.

[AidanC]

Thanks - I'll give it a flush and see if that helps.

The rack doesn't display any other symptoms - its not heavy at low speeds, isn't sticky or notchy in any other scenario so hopefully its not a terminal issue. There's only 50,000 miles on the car but I've no idea if the rack got heavy use despite the low miles.

[binty]

Thanks Aidan,
I noticed mine soon after I bought the car at 60,000 miles but tolerated it due to the cost of a new rack.
After 4 years and a further 60 000 miles, (I don't like to rush into things), I did the flush and cured it.
It didn't actually get much worse over that time, wish I had done it earlier though as it was so easy.
Please post how you got on.

[oragex]

The rack is damaged when an inner tie rod is replaced without using the special Volvo tool to secure the rack while tightening down the tie rod.

Hopefully it's not that. I wouldn't rush to replace the rack, especially if the issue doesn't seem permanent or annoying.

I've experienced something better described as a sudden 'disconnect' in the steering wheel, just like all of the sudden the steering at center was not connected to the wheels. I've tracked down to a camber alignment issue couplet with uneven pavement. Could well also be a loose bolt at the suspension, such as the two lower strut bolts.

[AidanC]

Originally Posted by oragex

The rack is damaged when an inner tie rod is replaced without using the special Volvo tool to secure the rack while tightening down the tie rod.

Hopefully it's not that. I wouldn't rush to replace the rack, especially if the issue doesn't seem permanent or annoying.

I've experienced something better described as a sudden 'disconnect' in the steering wheel, just like all of the sudden the steering at center was not connected to the wheels. I've tracked down to a camber alignment issue couplet with uneven pavement. Could well also be a loose bolt at the suspension, such as the two lower strut bolts.

Thanks - its had two new front drop links but the tie rods look original. Its interesting that you mention camber as I had a four wheel alignment done recently and even though the settings are within spec (apart from caster which moved out of spec for some reason), the car feels lighter and less planted on cornering now, especially where the surface is uneven.

Its booked in with my mechanic next week for towbar fitting and a brake fluid change. He's going to have a good look over it while he has it so we'll see what he finds. I probably won't get the flush done before then but should get to it the following weekend.

I'd agree that replacing the rack can wait until its a bigger issue or has safety implications.