Steering locked on a bend!!!!

[moggyadventurer]

Hi all,

I thought I would post this one for your thoughts and ideas. I was driving home last night and as I was going around the island steering to the left at first before bringing the steering back to the right to come around the island...well lets just say, it didn't come back to the right. Good job I was driving at about 15-20mph and the brakes are good . As I tried to bring the steering back to straight it literally locked. Luckily there was a cul de sac to the left, so i carefully mounted the kerb (no choice steering locked) and as i came off the kerb the steering was free again!

If ever I'd been driving at speed who knows what would have happened. I have knowb wheels fall off but never known the steering lock before.

Anyway I am about to start on it to route for a cause, any ideas or thoughts? Kingpins and trunnions were greased 300miles ago for mot, with steering rack and track rods regularly greased.

Grateful of any thoughts and comments and I'll let you know when I find out the problem

[bmcecosse]

Does the car have a steering column lock? Anything down in the footwell that could trap the column as it turns?

[lambrettalad]

I had the Same thing happen to me once in a GT6,turned out to be the under carpet wrapped around the knuckle at the base.

[chrisryder]

could it possibly be a trunnion becoming fully wound on on full lock, running out of thread and doing up like a nut and bolt?

[bmcecosse]

That's a possibility - and I always unwind the trunnion one full turn to make sure - but although Minors are know to understeer it would need to be quite something to get full lock going round a traffic island........ Have you fitted an anti-roll bar?

[moggyadventurer]

Hi,
Well first I checked the obvious, i.e something trapped down by the steering column...if only.
Then I checked both kingpins and top and bottom trunnions...all in free working order.
Did the waggle of the steering with a friend and whilst a little play nothing major. However it did feel slightly vague steering to the left. So I tried turning full locks and on the left.... a big clunk on full lock. You wouldn't believe how loud it was!

So disconnected the column and got the steering rack out, forgot how easy this was (fearing the worst)...all out in 50min.

At first no obvious signs of damage to the rack and pinion all well lubbed, however after undoing the nearside end (bowl)...the 6th and 7th teeth on the left side of the rack whilst still solid were visably worn (1/2mm down). With a little calculation, this was at the point were the steering had locked. As Id took the pinion out, I tried by hand to roll it through these teeth and it became clear that whilst it would still roll left, bringing it back caused the pinion to raise slightly and therefore lock between the two teeth once underload in its casing. Interestingly this was not picked up at MOT and in all honesty, there was not really any symptoms leading up to it. I must admit I'm pretty shocked by it.
Anyway this pm I went to get a recon box from a well known morris factor, and asked if they had heard of such a failure before. Low and behold, they said whilst until recently such failure was uncommon, they had experienced seven such failings to original boxes this year (all left side)...leading them to believe the fault may become more common as the cars get older.

Thanks for everyone who showed an interest

[moggyadventurer]

Hi bmce,

it was not on full lock, about halfish to the left..and no to the rollbar..original is best

[bmcecosse]

Well done tracking this down - and warning us all. Never heard of such a thing before - was the rack 'dry' - or was there plenty of grease in there? The comment re roll bar was slightly tongue-in-cheek.....

[lambrettalad]

wow scary !!!! do you have any pictures of the damage?

[Ratbag]

Probably due to greasing the rack instead of using the (recommended) EP90 (ducks

[bmcecosse]

Exactly the opposite - the oil runs away, the grease stays in place.......

[Ratbag]

But the failed ones were....what? Oiled or greased?

[moggyadventurer]

Hi all,

The rack was lubricated fantastic when it came out. Over the years I have used ep90 oil to grease it, though admit I may have greased it on occasion by accident more then by choice. Not one part of the rack was dry, all very clean to. To help with the debate further, the morris factor I went to now recommends a graphite grease over ep90 for its sticking properties...however oil does seep better than grease.

[fussyoldfart]

Well, I know one rack that will get a thorough once-over before the car goes back on the road.

Darrell

[kennatt]

Do you think you need to strip down to have a look or would you feel anything if jacked up and turned lock to lock,bit worrying would think everyone should check it out though.Certainly going to have a look at mine.