Steering shenanigans

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eprothe

Member
Posts
84
Location
Scotland
Hello,
The steering on my 110 Td5 went mad the other day...it suddenly developed a massive speed wobble at about 40mph.
I went for the easiest fault and checked the PAS fluid - imagine my surprise at finding it fully emulsified. "Ah ha," I thought, "pump failure." So, one new PAS pump later and a complete fluid change (my God, that's a messy job), I took it out for a test and b*gger me if wasn't just as bad. It turns out, after a proper look, one of my track-rod ends has failed - completely split boot and very lumpy movement.
I'll fit a new pair of ends tomorrow, but the failed one's only got about 2000 miles on it - surely even Britpart cr*p should last longer than that?
I'd be grateful for any thoughts on what the root cause might be here - I don't want to be going through track rod ends at this rate!
Thanks :)
 
Sounds to me as though the swivel preload is out, this does cause a very dramatic wobble if it really gets going.
This in turn can cause damage to the whole steering system, track rod ends especially.
 
Thanks for your thoughts.
I'm pretty confident my bushes are fine - I did a complete change over to poly bushes 2000 miles ago, too.
Swivel joint preload is a new one on me, though - how do I set/check that?
Thanks :)
 
Thanks for your thoughts.
I'm pretty confident my bushes are fine - I did a complete change over to poly bushes 2000 miles ago, too.
Swivel joint preload is a new one on me, though - how do I set/check that?
Thanks :)
Did you use cheap bushes?
The swivel preload is one of those jobs that's a bit of a faff on but not difficult, if you've done it before. If you haven't it'll be a bit of a pain. I'm on my phone and can't post the relevant section from a manual, someone else might though. I'd be giving the new panhard rod bushes a thorough investigation with a pry bar.
 
They were proper, pukka poly Bush bushes - no expense spared :)
I've read up a bit on swivel preload, checked mine and it's about half the recommended figure. I've read it should be 15lbs, which is about 7kg and mine are somewhere around 3.4-3.6kg.
From what I've read, I need to remove the top pin bolts, take out a shim and tighten it back down, then test the preload again - is that about it?
Thanks for your help with this :)
 
From what I've read, I need to remove the top pin bolts, take out a shim and tighten it back down, then test the preload again - is that about it?
That is exactly it, Bit of a fiddle swapping the shims about until it is correct but it will make a difference. Despite being low mileage proper polybushes I would still check them over whileyou are working on it. The pan rod is another well known cause of the death wobble you describe.
 
Good point - despite my best efforts, it leaked a bit, though.
I've managed to improve things a bit:
O/S: 3.5kg - > 6.5kg
N/S: 0.5kg - > 5kg
I basically removed a thin shim from each side. I can't re-fit the tracking rod, though, as my ends have turned up but only one of them is for a Defender...
How do you tell how much grease is in the hubs? I sucked all the old grease out and refilled them a while ago, but it'd be nice to know how much leaked out.
Thanks for your help :)
 
Oh yeah, I checked the panhard rod bushes and there's a bit of movement at the axle-end (2-3mm axially) but that seems within tolerance to me...
 
Oh yeah, I checked the panhard rod bushes and there's a bit of movement at the axle-end (2-3mm axially) but that seems within tolerance to me...
Sounds like you're doing a great job with the preload. That sounds like a lot of movement on the panhard rod and will likely be the source of your wobble. Is the movement the bush or the bolt in the bracket?
 
Oh yeah, I checked the panhard rod bushes and there's a bit of movement at the axle-end (2-3mm axially) but that seems within tolerance to me...

On which axis - the bolt or along the rod itself ? - this will tell you where the issue is - there should be no play in either end of the Panhard rod - the only movement should be elastic deformation of the "poly" or "rubber" part of the bush ....
 
Well done for adjusting the preload, not too bad a job once you pluck up the courage to do it.
Keep the shims in a safe place for next time when you can take out a thicker one and replace with the thin ones.
Or be like me and forget where they are and have to order more, then before they arrive, there they are in some out of the way place.
 
Oh yeah, I checked the panhard rod bushes and there's a bit of movement at the axle-end (2-3mm axially) but that seems within tolerance to me...
That sounds like more play that you want in the end of the panrod. It doesn't take much to give some pretty terrifying results.
 
I'm not sure whether the TD5 has the ABS Raiko bush swivel pin? If not, ignore this.

The swivel preload isn't really the answer to a worn bush. The bush works in two ways. One by being a 'nice' fit on the swivel pin, and that locates the top of the housing accurately whilst allowing it to steer. Secondly. the pin pushes on the bottom of the bush, forcing the swivel housing upwards, which lifts the lower pin into the tapered roller race pressing it up into it's track in the swivel ball. By adding preload to the bush you're making sure that the taper roller is working as it should and neither floating about nor binding.

What preload does not do is make any (lasting) difference to a worn bush - the pin will move around in it as you brake, accelerate or put lateral loads on it by cornering. To test it you need to jack the axle and a) with hands at 12 and 6 o'clock rock the wheel in and out, and b) with the brake on try rotating the wheel. What you're trying to feel is play in the top pin and bush, not the lower taper bearing. If you find any, it's new bush time.

I say lasting difference because you can whack them up really tight and get the impression that you've removed the play but you haven't, you're just pressing the pin on the bottom of the sloppy bush and it won't stay tight for more than a few corners.

What adjusting the preload at regular intervals will do however, is to stop the bottom taper floating about which in turn stops the pin being twisted in the bush, and that'll make the bush last longer.
 
I'm not sure whether the TD5 has the ABS Raiko bush swivel pin? If not, ignore this.

Td5 should have the later axle which has a bearing top and bottom rather then the top bush. But everything you have said regarding the bush is of course correct if the bush or the bearings are worn the correct remedy is to replace them. the preload setting is purely for setting up and adjusting not correcting failing components.
 
Hello all,
Thanks very much for all your advice and encouragement :)
The movement in the panhard rod is along the rod itself - there's no play across the Bush at all. To me, it seems just deformation of the Bush, but I'm going to check the torque on the mounting bolt, as it moved slightly when I forced the rod with my pry-bar.
I'm pretty certain the swivel pins have bearings rather than bushes at the top, as I reckon I could see them down the pin holes...
Thanks again :)
 
Hmm.. Well, I'd estimate the torque on the axle end bolt to be about 0lb.ft - it's now 65lb.ft as per the Haynes manual. I have to say, that's rather an embarrassing turn of events - I can't imagine it worked its way loose, as it's nylock, so I must have forgotten to torque it properly when I fitted the polybush kit...
I'm away to check the torque of everything else now...
 
Thanks for not commenting on the panhard rod bolt :)

My replacement track rod end turned up today, so I put everything back together and took it out for a drive.

It's definitely a lot better - no speed-wobble and the steering's not as light as it was. It still feels a bit vague and "wandery", though, so I'll get the tracking checked properly. There's also a bit of a clonk coming through to the wheel when I come back up the dirt-track to my house and go over the occasional rock...

Thanks for your help, everyone :)
 
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