Thread: Defender swivel preload value?

Originally Posted by MinniTheMoocha

Just thought I would mention that the "death wobble" is 98% gone .

Normally on my way to work it would happen at the same place. But now it doesn't. I am much more comfortable going above 90km/h and hitting bumps without having the grab the steering wheel in anticipation.

I said 98% because I had some vibration/wobble affect but not at all like the "death wobble" My suspicion is that the left side swivel could also do with some extra pre-load and getting the wheels balance properly is proving quite difficult.

The reason that the tyre shops struggle balancing the wheels is they simply use a cone to centre the wheel. It does not always work because of wheel offsets and ridges on the defender wheel hub hole. They just keep putting heavier and heavier weights on. The tyre place told me I had a buckled wheel, when they swapped over my spare they said it also was buckled which was impossible as it was a brand new rim! When they showed me the wheel was basically hopping up and down. I got the manager over and he then realised that the cone was not centring the wheel and used an adjustable plate that uses the wheel stud holes to centre it. Was able to halve the weights fitted. Because it was late on a friday before the long weekend and it was already 20 minutes past 5 they were keen to go so I didn't get both front wheels properly balanced nor the spare which was "buckled" I am sure it isn't.

I would also not rule out the 2% being your steering damper...when your swivel preload is out for a long time it can make your damper work overtime and wear it prematurely.

If you have almost got it right I would be inclined to take of the damper and take it for a drive to see whether the 2% has gone or not before making any further adjustment

If you have ABS, as fitted to most Td5 Defenders, then the preload is HALF that of Non ABS models. The lessser figure quoted earlier would've been for ABS model. They have a thrust washer/ bearing/ washer and a pin/ bush assembly in the top instead of 2 taper roller brgs top and bottom.

Excessive swivel preload for ABS models will very quickly ruin the top bearing and thrusts.

JC

Originally Posted by justinc

If you have ABS, as fitted to most Td5 Defenders, then the preload is HALF that of Non ABS models. The lessser figure quoted earlier would've been for ABS model. They have a thrust washer/ bearing/ washer and a pin/ bush assembly in the top instead of 2 taper roller brgs top and bottom.

Excessive swivel preload for ABS models will very quickly ruin the top bearing and thrusts.

JC

Fortunately mine is non ABS. 1998 300Tdi model, dual 606666 bearings in the swivel. In the next couple of weeks I will take a proper measurement of preload without swivel seals, brake callipers attached etc to know for sure.

That's because the swivels seals are leaking slightly (I run straight 80/90) and will probably use 80/140 so it's a bit thicker and less likely to leak but will replace the seals nonetheless.

Unless somehow this oil is not good for bearings etc.

Originally Posted by dullbird

I would also not rule out the 2% being your steering damper...when your swivel preload is out for a long time it can make your damper work overtime and wear it prematurely.

If you have almost got it right I would be inclined to take of the damper and take it for a drive to see whether the 2% has gone or not before making any further adjustment

The damper is very unlikely for me as I installed it only about 4 or so months ago with a RTC Terrafirma.

Can I just remove one end of the damper, cable tie it to the steering arm or remove it completely?

As an addendum to this thread, I will point out what I have in other similar threads.

As with most steering problems, it is unlikely that there is a single problem. It is probably contributed to by a number of minor shortcomings, and fixing any one of these will at least temporarily stop the wobble, until one of the shortcomings gets bad enough to result in wobble even if everything else is perfect.

Wobble is initiated by a number of factors, including out of balance wheels, out of round wheels or tyres, and bumps on the road (the wider the tyre the worse they are likely to affect it). Wheel balance should be the first step.

Its amplitude is limited to the free play in the steering plus free play in the Panhard rod, plus, if it is vigorous enough, any movement in the wheel the driver cannot restrain. Removing all this free play should be done by replacing bushes and tie rod ends. Note that wheel bearing free play shows as steering free play. All of these are more significant for other steering problems than for wobble.

Wobble is maintained by the self centring action, largely the caster action of the caster angle, but partly from king pin inclination. Increased caster angle from raised suspension increases this effect. Larger and heavier tyres help maintain it once started.

The wobble is dampened primarily by the swivel preload (this has the advantage of being before any possible free play), and secondarily by the steering damper. There is probably a small additional effect from the shock absorbers as well.

John

Originally Posted by JDNSW

As an addendum to this thread, I will point out what I have in other similar threads.

As with most steering problems, it is unlikely that there is a single problem. It is probably contributed to by a number of minor shortcomings, and fixing any one of these will at least temporarily stop the wobble, until one of the shortcomings gets bad enough to result in wobble even if everything else is perfect.

Wobble is initiated by a number of factors, including out of balance wheels, out of round wheels or tyres, and bumps on the road (the wider the tyre the worse they are likely to affect it). Wheel balance should be the first step.

Its amplitude is limited to the free play in the steering plus free play in the Panhard rod, plus, if it is vigorous enough, any movement in the wheel the driver cannot restrain. Removing all this free play should be done by replacing bushes and tie rod ends. Note that wheel bearing free play shows as steering free play. All of these are more significant for other steering problems than for wobble.

Wobble is maintained by the self centring action, largely the caster action of the caster angle, but partly from king pin inclination. Increased caster angle from raised suspension increases this effect. Larger and heavier tyres help maintain it once started.

The wobble is dampened primarily by the swivel preload (this has the advantage of being before any possible free play), and secondarily by the steering damper. There is probably a small additional effect from the shock absorbers as well.

John

This sounds just like my situation. One of my other posts was about bearing play. I have been trying to get to the bottom of this problem and working through each of the possible issues. (slowly I might add)

It was lifted with new springs and shocks (shocks were shot! and I was sagging badly) which resulted in a much better ride and less of a problem.

I put in castor correcting bushes which did help with wandering and steering feel. But got a bit of vibration from front drive shaft (yet to be replaced with DC or wide angle yoke) due to diff angle.

Then got an alignment which improved tracking.

Tyre tubes needed to be replaced (two flats in about three weeks) and the problem was back with vengeance. Got wheel balance which improved it quite a bit.

Swapped over to my muddies and for quite some time it improved. Had to swap rims on the muddies and the problem resurfaced badly. (Wheel balance definitely a contributing factor)

Replaced steering arms (bent them) but this included all new tie rod ends.

Replaced damper with RTC to improve steering.

Replaced Panhard rod with adjustable type to improve alignment as originally only used standard one (this included new poly bushes, I normally use rubber but think this is one area where the poly's would be fine)

Finally adjusted preload which I should have looked at earlier because I am pretty sure the right side was too loose as it swung fairly freely.

I am still sure wheel balance is contributing a little and will get a proper wheel balance all round because as mentioned earlier the tyre place had a hard time getting it centred properly.

But now having done the preload on the right side my confidence is back!

Thanks to all contributors.

Originally Posted by MinniTheMoocha

The damper is very unlikely for me as I installed it only about 4 or so months ago with a RTC Terrafirma.

Can I just remove one end of the damper, cable tie it to the steering arm or remove it completely?

HoW is the RTC Terrafirma damper. Am changing mine to that hopefully! Need to get rid of the death wobble.

Originally Posted by prith

HoW is the RTC Terrafirma damper. Am changing mine to that hopefully! Need to get rid of the death wobble.

You would be better off fixing the wobble and then fitting the damper..not fitting the damper to mask a problem