Sudden, very stiff steering

Greetings,
300tdi defender 110

Steering just suddenly went very stiff after engine startup and attempting to move. No noises from pump, fluid still at high level in reservoir and tire pressures are good.
A normal turn is now taking 3 attempts backwards and forwards. Any ideas as to what this could be?

is pump actually been driven

You forget to tell us whether the belt is ok?

Thanks for the reply. I believe the pump is being driven by the belt. I left the vehicle in a secure place and will be back to have a better look tomorrow in the sunlight.

Discokids said:

You forget to tell us whether the belt is ok?

Click to expand...

In relation to the belt, the condition is not the best. It has several cracks etc but it appeared to be running along the pulleys as usual. I will repost after a more thorough inspection.

Plenty of power steering fluid? If it's empty it's gonna get really heavy.
1st check would be the belt though

LeftFoot said:

Thanks for the reply. I believe the pump is being driven by the belt. I left the vehicle in a secure place and will be back to have a better look tomorrow in the sunlight.

In relation to the belt, the condition is not the best. It has several cracks etc but it appeared to be running along the pulleys as usual. I will repost after a more thorough inspection.

Click to expand...

it been known for pulley to spin but pump not trun

Sorry for the delayed responses, i'm in a different time zone to you guys. -5hrs. Ok i've done the following:
1. Released tensioner,slackened belt and PS pump pulley turns easily.
2. Belt condition checked. Not perfect but functional.
3. No PS fluid leaks. Just a bit of moisture around hoses at ends.
4. Steering damper removed with same effect.

I was considering the steering shafts UJs but visually all appears fine. So i soaked the shafts with penetrating fluid and slowly took the drive home. Surprisingly the steering was normal all the way home through several twists and turns.

So, i would assume at this point that perhaps the UJs on the shafts might have been seized or there may be an intermittent issue with the power steering. The steering was so stiff before that i had to fight it to make basic turns.
I have a nagging feeling that I have not seen the last of this. Any suggestions?

If the steering gear was stiff then you would hear the pump straining hard (like it does if you are on full lock).. With the belt off turn the pump slowly by hand, both ways you should be able to feel the internals turning (small pulses), if the pump feels totally smooth then the pump may have sheared the shaft internally.

I've certainly had my steering become very difficult and the fault turned out to be the steering UJs. I had WD40 with me at the time which temporarily sorted the problem, I've since greased the UJs thoroughly and not had the problem since.

Kwakerman said:

If the steering gear was stiff then you would hear the pump straining hard (like it does if you are on full lock).. With the belt off turn the pump slowly by hand, both ways you should be able to feel the internals turning (small pulses), if the pump feels totally smooth then the pump may have sheared the shaft internally.

Click to expand...

Thanks i will try this. Interestingly, i've found that once i start up and drive the steering gets lighter. While driving a short distance and then parking everything feels like normal. However after leaving the defender parked and attempting to drive after results in the stiffness. Am i right to assume this points to the PS pump losing pressure?

As an update:
Power steering would go and come intermittently. Sometimes light as a feather for a day or two and other times incredibly stiff. When without power steerimg sometimes while putting lock in I would hear a thump and the pressure from the pump would suddenly engage even to the point of jerking the steering wheel in my hand and the steering would be fine once again.

Here are two things I observed:
1. When the steering is fine and while parked with engine running and someone turning the steering wheel full lock left to right the pressure hose with the crimped ends will swell indicating pressure is building. But when the steering is stiff and the same test is carried out the same hose remains umchanged.

2. There are small metal filings in the power steering reservoir. Seen with a spotlight.

Could this indicate an intermittent blockage somewhere? Are there any filters of any sort which could be cleaned?
Any suggestions are welcome. I plan to start to pull down on Saturday to investigate more.

Seems like the box is on the way out,filings in the oil is bad news. Mine went this way so it is renewal time,flush the pump out when you do the job.

Update:

Took belt off of the P/S pump today and discovered what I didn't last time - some significant slack while turning the pulley from side to side. Definitely felt like the shaft in the pump was slipping. With the assistance of a friend I took the fan, fan cowl, top radiator hose, top intercooler hose off. Next I disconnected the pump hoses and removed pump.

Opened up the pump to find that the key on the shaft which holds the gears on snugly was completely worn leaving the shaft to spin freely. . It was a miracle that the power steering would even work intermittently. I reckon when the key shifted and wedged at an angle then the gears will spin. That also explains the metal filings found earlier in P/S reservoir.

We fabricated a new key and reassembled the pump. Unfortunately I did not take pics but on reassembling the pump, the thin plastic like gasket which seals the two halves of the pump together had to be reused with the addition of a thin smear of RTV on both sides. Not too sure if this will ultimately hold but I guess time will tell.
After reassembling the P/S circuit we had to take some time to refill the coolant at the thermostat housing because coolant was lost when the top radiator hose was disconnected to make room the fan cowl removal. Naturally, despite my being extremely careful, the plastic plug broke off in the thermostat housing.
This of course meant time had to be taken to remove the threaded part and find a replacement plug. My mate was able to find a replacement plug after the remains of the plastic plug were cut and dug out.

When all was finished the PAS system was bled and I took it for a test drive. Absolutely no issues encountered during test drive or during drive home.
However at home after parking, I passed by the defender and noticed a red puddle. I will further investigate this in the morning to determine if this is due to a lose hose or if this is from my "custom seal" on the pump.

Ultimately I will purchase a new pump, todays efforts are just to get me by the weekend. Will update tomorrow.

another pump is best fix

I would suggest pump too.. had a bmw that was stiff I had to rev the engine to work the pump harder to park it but actually driving it felt fine

Update:
P/S fluid was leaking from two halves of the pump that was reassembled.

Bought new P/S pump on Monday and installed it. Relatively straight forward installation and all appears well now.
So i'll sit now and wait for the next issue.....

great info, good to see you sorted it.