Cerb takes offence - power steering failed
Cerb takes offence - power steering failed
Author
Discussion

Captain Beaky

Original Poster:

1,389 posts

313 months

Monday 13th June 2005
quotequote all
So I popped into my local dealer to test drive the Tuscan 2 - not that I'm thinking of changing, just keeping an eye on developments. The Cerb was obviously offended however becuase on the way home the power steering failed...

The dealer can't even look at it for a week and I'm intending to take the car to France in two weeks. Any words of wisdom on what I could be up against ?

[small]98 4.5. And yes, I've checked the fluid[/small]

Mark Adams

358 posts

289 months

Tuesday 14th June 2005
quotequote all
Do you have any more info on how the steering actually failed? Has it lost assistance, or is there a more obvious mechanical problem?

May then be able to point you in the right direction...

Captain Beaky

Original Poster:

1,389 posts

313 months

Tuesday 14th June 2005
quotequote all
Mark Adams said:
Do you have any more info on how the steering actually failed? Has it lost assistance, or is there a more obvious mechanical problem?

May then be able to point you in the right direction...


Hello again Mark

It started losing assistance for just a fraction of a second in corners, as though the pump had stopped or run out of fluid. Then the fractions of a second turned into whole seconds, making cornering interesting and a bit unpredictable. Now it's not assisting at all. In other words the assistance is normal while it is there, it's just not there enough !

Feels like a pump failure rather than a joint. I've only had one pump failure before (in a Jeep) but that would be my guess.

Mark

P.S If only it had failed on Friday when we met at Austec with Simon's Griff, they could have looked at it then...

Extra 300 Driver

5,282 posts

275 months

Tuesday 14th June 2005
quotequote all
if it is the rack www.power-steering.co.uk

They are in Greenwich and will do a full overhaul of a Cerbera rack for £130, warranty as well!

>> Edited by Extra 300 Driver on Tuesday 14th June 20:13

gazzab

21,627 posts

311 months

Tuesday 14th June 2005
quotequote all
are you sure it isnt the uv joint? Does the steering feel 'square'?

Captain Beaky

Original Poster:

1,389 posts

313 months

Wednesday 15th June 2005
quotequote all
gazzab said:
Does the steering feel 'square'?

That's a good description but no, it doesn't feel square. If I'm cornering with the wheel in a fixed position I can feel the assistance coming and going.

Another clue might be that I heard twittering noises from under the bonnet while stationary. I thought it might be a loose belt but the power steering is shaft driven.

Julian64

14,325 posts

283 months

Wednesday 15th June 2005
quotequote all
Interesting problem. I would have said although it could be the pump its unlikely as the way the pump works inside it should be working or busted, and no real scope for a half way house you describe.

The pump works by pumping oil around a quil shaft and down two small holes. Possibly broken quil shaft or blocked holes from all the crud that collects?

Sit in your car stationary with the engine off. Rock your steering wheel gently side to side and tell us how much play you have before you feel your starting to take the weight of your wheels.

Captain Beaky

Original Poster:

1,389 posts

313 months

Wednesday 15th June 2005
quotequote all
Julian64 said:
Sit in your car stationary with the engine off. Rock your steering wheel gently side to side and tell us how much play you have before you feel your starting to take the weight of your wheels.


Right, I'll give that a try tonight and let you know...

matt101

299 posts

288 months

Wednesday 15th June 2005
quotequote all
95 % sure it will be a sheared woodruff key on the shaft that drives the PAS pump. Happened to mine twice and ended up converting to electric PAS, supplied by Joospeed and fitted by andy at APM.

Apparently pre 98 cars had a thinner shaft and smaller keyway which makes them prone to shearing. Cars after this date had beefed up parts to fix the issue.

Its quite expensive to retrofit the new style shaft as I think the engine needs to be removed. It may be possible to fit a new woodruff key but this will be prone to going again as it did with mine.


Electric PAS conversion was less than half the cost of the later style PAS assy.


Also, when mine went it made twittering noises on both occasions!!! also, as it starts to go, you get PAS one second, then nothing. This gets worse until there is no assistance at all.

>> Edited by matt101 on Wednesday 15th June 17:16

Captain Beaky

Original Poster:

1,389 posts

313 months

Wednesday 15th June 2005
quotequote all
Sheared woodruff key ? Hmmm, that sounds (a) expensive and (b) unlikely to get fixed before I go to France at the end of the month.

If Joospeed was still in business the car would be there already ! I'm guessing that my local dealer might not want to do a non-standard conversion but I'll see what they say.

Annoyingly I was down at Austec and staying in Liphook near APM last week and the car was fine...

Captain Beaky

Original Poster:

1,389 posts

313 months

Thursday 16th June 2005
quotequote all
Julian64 said:

Sit in your car stationary with the engine off. Rock your steering wheel gently side to side and tell us how much play you have before you feel your starting to take the weight of your wheels.


I tried moving the steering wheel while stationary, resisiting the temtation to make "Brrrm-pop-pop" noises at the same time.

The steering feel seemed "normal" - the wheels moved almost immediately when the steering was moved, getting very heavy after, say, an eighth of a turn when any free play and tyre flex had been taken up. Same in both directions.

Julian64

14,325 posts

283 months

Thursday 16th June 2005
quotequote all
Captain Beaky said:

Julian64 said:

Sit in your car stationary with the engine off. Rock your steering wheel gently side to side and tell us how much play you have before you feel your starting to take the weight of your wheels.



I tried moving the steering wheel while stationary, resisiting the temtation to make "Brrrm-pop-pop" noises at the same time.

The steering feel seemed "normal" - the wheels moved almost immediately when the steering was moved, getting very heavy after, say, an eighth of a turn when any free play and tyre flex had been taken up. Same in both directions.


Okay I think that effectively rules out top of rack. It does sound like its simple pressure fluctuation.

However I would have thought that woodruff key once broken would be the end of any power steering and it wouldn't return. I think the experience of the previous poster is rather against that theory

matt101

299 posts

288 months

Thursday 16th June 2005
quotequote all
I think, as the key shears off in the Keyway, the PAS pump drive still has a little bit of grip on the shaft but as soon as any real load is applied, the shaft spins without driving the pump at all. This results in the on/off PAS that you describe.

This does not last for long as the more the shaft spins, the more worn the damaged woodruff key becomes and you end up with no PAS at all as the shaft simply spins in the PAS drive.


The woodruff key itself looks a bit like half a £1 coin. This fits into a slot on the shaft and is designed to shear under certain conditions. The part is very cheap but its the difficulty in getting to it that made it expensive to fix in my case.

kojak

4,547 posts

282 months

Thursday 16th June 2005
quotequote all
The woodruff key was a fault on the early cars, but was modified later. As pointed out...its not cheap to put right. £800+ I think. Jools used to do a mod taken from the Tuscan I think, which is an electrical one. It was cheaper.

Captain Beaky

Original Poster:

1,389 posts

313 months

Thursday 16th June 2005
quotequote all
kojak said:
Jools used to do a mod taken from the Tuscan I think, which is an electrical one. It was cheaper.


Does anyone else do this (in the North preferably) ?

matt101

299 posts

288 months

Thursday 16th June 2005
quotequote all
I'm pretty sure that any competent mechanic could do this for you as long as you have the correct bits. I'm sure a quick e mail to Joolz would give you the info you need as he supplied the kit for the electric PAS conversion on mine.

Andy at APM had never done this conversion prior to doing mine but once we had all the parts, I don't think it was too bad. (maybe Andy should answer that!!)
Cost for conversion was approx £500 against well over a grand to retrofit the later style shaft. Repairing the sheared key is the cheapest (if repairable) but there's nothing to say how long it will last. In my case it was less than 6 months.

Julian64

14,325 posts

283 months

Thursday 16th June 2005
quotequote all
One last point, there was a TSR on chassis numbers before TC0011301. A known problem was fatigue cracking of the pump bracket which led to intermittent failure of the power steering, and bending of the shaft.

TVR bought out a mod to solve this for the later cars. If you email me your chassis number I'll let you know whether you are on the list or not.

Captain Beaky

Original Poster:

1,389 posts

313 months

Monday 20th June 2005
quotequote all
The verdict is in from the Harrogate jury. Broken woodruff key with some damage to the driving shaft.
The options were:

1) replace the shaft and key, which means taking out the engine

or

2) disconnect the standard pump and replace it with an electric one, as used in Tuscans and T350s (and Citroen Saxos it would seem...)

Timing, common sense and financial prudence all point to Option 2. Fingers crossed we'll be back on the road in a couple of days and off to France next week.

Huzzah !

Julian64

14,325 posts

283 months

Monday 20th June 2005
quotequote all
Captain Beaky said:
The verdict is in from the Harrogate jury. Broken woodruff key with some damage to the driving shaft.
The options were:

1) replace the shaft and key, which means taking out the engine

or

2) disconnect the standard pump and replace it with an electric one, as used in Tuscans and T350s (and Citroen Saxos it would seem...)

Timing, common sense and financial prudence all point to Option 2. Fingers crossed we'll be back on the road in a couple of days and off to France next week.

Huzzah !


I feel I speak for everyone when I say could you add that to the parts thread, and how much?

Captain Beaky

Original Poster:

1,389 posts

313 months

Monday 20th June 2005
quotequote all
No problem, I've added the info to the part numbers thread.

I don't know the cost yet. I'll report back when I've got over the inevitable shock...