Heavy steering - MOT failure

[Chris F]

It was MOT time last weekend after having the 7 off the road for 6 month. It failed because just past straight ahead the steering tightens up before it loosens up again. (is this because I didn't move the steering wheel enough while it was off the road?)

 

I had the rack off and oiled/greased it - still a problem. ☹️

I disconnected the UJ joint - still a problem ☹️ ☹️

I adjusted it using the allen key adjuster (both tried loosening and tightening it) - still a problem ☹️ ☹️ ☹️

 

Any other ideas or does it need a refurb?

 

(If its a refurb how quickly do titan turn it around - will I make my MOT retest with having to book it in for the full test again?)

 

Chris

[Molecular--Bob]

Mine did something similar, and it was the bushes in the upper steering column that had failed. A lot cheaper to try these before putting a new rack in.

 

If you have some silicone spray try a quick blast into each bearing and see if it eases the stickynes. If it does you should still replace them, but it might point to them being the problem.

 

Should add that in my case the failure was so bad that grit had got in and scored the column as well, so i had to fit a new one as well as the bushes

[Chris F]

Thanks Bob but it can't be the steering column/bushes in my case as it still does it with the column disconnected

[Graham Perry]

Assuming its the current high ratio aluminium cased rack you are talking about ?

 

The rack is very simple I would take it off the car and mount it in the vice and adjust it there. Take the adjuster screw right out and the large mounting nut that it mounts in. CARE there is a small spring under it under load which you won't want to lose. Under the spring is the plastic slipper that puts the pressure on the rack and adjusts it, remove that and then test if the rack moves freely, which it should do. If it doesn't then it should be obvious what the problem is such as lack of grease or something fouling the movement of the arms. I would also remove the rubber boots so you can view the ends of the rack. It is possible to put too much pressure on the adjuster spring so that it fully compresses it, in which case the rack will be tight as it cannot take up any normal upwards or downwards movement in the rack arms as they move from left to right. You will see that they float up and down slightly as they move from left to right.

 

Along with a few other changes, I fitted a much stronger traditional type of spring to mine with more travel and the problems of inconsistent feel disappeared.

 

 

 

Edited by - Graham Perry on 31 Mar 2009 10:45:25

[Chris F]

Graham,

 

Don't think its the same rack. My car was 'factory' built in 1996.I only bought it in 2006 but assume its the original rack.

 

I don't have a spring on the adjuster. The adjuster screws onto a shaped hard black rubber insert which applies the pressure. When you remove this you can't see much, just the top of the rack that is smooth aluminium. Grease in it seemed quite thick to me so I put in some lighter grease and tried to remove some of the thicker stuff.

 

Chris

[Graham Perry]

Its sounds slightly different to mine. I am surprised that it doesn't have a spring as the few racks I have looked at (on other cars) have usually had one. Maybe the rubber fulfills a similar role ?

[stevefoster]

You might need to get grease all the way from the adjuster opening to the far end.

 

I took the gaiter off that end and filled it with light grease, put it back in and used it as a bellows to squeeze grease in from the far end - after several repeats to fill her up, it worked a treat.

 

Add lightness, says the man with a VX :-)

My racing & other pics

here

General pics (mostly of 7's and cars).

here

 

[Normans_Ghost]

I've always used EP90 in racks as grease tends to dry out leaving the moving bits dry.

 

Not sure what the book of words says, this is an experience thing.

 

^{Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here}

You and your seven toThe French Blatting Company Limited

[Peter T]

EP 140 is better still.

 

 

[patneale]

I too had a problem with my 2003 car's steering rack. It almost locked solid in the straight ahead position after 1000 miles and was terrifying as it stayed on lock after a roundabout or turning ! Jez Coates took rack off( I had already removed the track rod ends at home in case the king pins had never been greased and it was definitely the rack) and discovered a very odd fact. If you pushed and pulled on the rack, once you had overcome the friction and got it moving it went effortlessly from lock to lock, but if you stopped moving it, it all but locked solid and required a big push to get it moving again. The manufacturers had just started coating the ends of the rack with ptfe on the area where the rack runs through the end bushes and he reckoned for some reason this was causing the problem. Never did find out why this was happening, but new rack has been fine and they stopped putting ptfe on the rack and all was well. Jez reckoned they had about a dozen of these rack problems..... Perhaps your car has had one of these rogue racks fitted some time and it has only just come to light........If you have loosened the big nut and undone the allen keyed adjuster a little and it is still tight, then it might well be one or both of the end of rack bushes which is the problem.

[c7trp]

I had a similar problem to this and eventually traced it to the spherical bearings in the lower wishbones.

 

For a while, I just oiled them every few hundred miles and it made a massive difference.

 

In then end I replaced them. They were very worn, but the wear is quite hard to detect when fitted to the car.

 

Due to the camber the spherical bearing wears unevenly, and now with the experiance of this, you can 'feel' the roughnes of the bearing if you disconnect the trackrod and rotate the hub assy from lock to lock.

 

HTH

[stevefoster]

You can detect lower wishbone wear easily with the trunnion test.

Jack up wheel about 2" off the ground. With a long bar 3' or more lever the wheel vertically up and down. Watch trunnion or Sph bearing in this case. Does it move vertically?

 

You can also just lift the wheel vertically from above and detect play as the 7 front corner is so light...

 

Add lightness, says the man with a VX :-)

My racing & other pics

here

General pics (mostly of 7's and cars).

here

 

[Chris F]

That was one of my first thoughts and so had a go at it yesterday but it seemed fine.

 

I took the steering rack gaiters off and cleaned out the insides of the rack as much as possible. I then flushed it out with light oil before adding some thicker oil to it. Its not perfect but a lot better so I'm going to give the MOT another go. If that doesn't work I'll send it off to Titan for a refurb.

 

The seal where the column/pinion goes into the rack seems to be seeping oil though so reckon I'll have to do something about that reasonably soon.

 

Thanks for all the replies!

 

[patneale]

Chris F

 

Hope you have sorted problem.... You now have a good range of possible problems from column bearings, rack end bearing to bearings in the wishbones. Disconnecting the various parts will help you establish which is at fault.

What was it in the end ?

 

Hugh Robinson.

[Chris F]

I reckon it was the rack... not sure why it has improved, maybe some debris in it that I managed to flush out with the light oil???

[patneale]

Good news Chris ... Hope it passes.

It appears that there is a tendency for the QR steering wheels to get slightly loose on their splines and there was a case of MOT failure on a C reported last year. Mine is the same..... Andy Noble of CC suggested a fix. Use a mole grip to slightly squash the splines on the column....... Be ultra clearful as too much and you will not get the wheel back on again. I did it and it worked for several months.

 

Hugh Robinson