Thread: Help: Rattling noise & vibration in front end at specific speed

Found this on the LR4x4 forum, posted by "Andy J"

Front end wobble of death

Symptoms -
Around 60-65mph the front end can go into an uncontrollable spasm of vibrations that can frighten the pants of anyone. Usually goes away once you have braked to a speed of about 30mph, regain your pulse and crawl on a bit more

Fix - On both my discoveries (1990 and 1994 models) this has always turned out to be swivel pin pre-load. Fixing is relatively simple and there are posts on this website to help

Believe me, i know the frustration and money that can be spent in fixing this problem. I have been through the whole replace bushes, steering damper, steering box, steering u-joints baloney! If you have this problem it is your swivel pre-load. If any of the other items are shot (a) there are specific symptoms that will prove this and ( they are probably shot from the death wobble caused by your swivel pre-load.

Explanation. The entire wheel assembly is hinged in the vertical plane on the upper and lower swivel pins. When pre-load is set correctly these pins pinch the swivel bearings such that there is no horizontal play. However over time, the swivel bearings (which take the brunt of the load) obviously wear a little, creating some slack in the horizontal plane. The best way to visualise the effect is to spin a coin on a desk, just before the coin finally comes to rest it has a frantic wobble/vibration just before it comes to rest. At this point the coin is rotating both in the direction you spun it AND horizontally (inline with the desk). If you watch a coin at this point, that is exactly what your front wheel(s) are doing. Im 150% sure of this - this wobble is swivel preload - other suspension/steering faults do not cause this effect (though they will get damaged the longer the pre-load is not set correctly)

As others have said, swivel preload is important. But so is the health of the bearings. They don't last for ever, especially if they've been doing the 100kph shimmy for some time. Expect all the rod ends to be stuffed if old and exposed to the same shimmy.

Also, I've never had new tyres on our Disco, just second hand tyres bought over the years as sets. I've found that balance is vital and ensuring that the wheel nuts are done up progressively to ensure that the wheel is properly centred on the studs makes a difference. I run somewhere between 0mm and 1mm toe out at the insides of the rims, and set this myself.

I vote for suspension bushes.

Had the same issue with my Jeep WJ, and found out the control arm bushes were all cracked.

Would love info on how I could fix these t6hings. For example is the bushes thing easy to do? What parts would I need to buy (specifically)

I am mechanically useless but willing to give tings a go as long as I have some idea how to proceed.

Assuming a d1 is similar to a 95 defender,
The bushes and swivel bearings are fairly easy to do.
I just recently done mine with only the rave manual and this forum to get me through. It was a success.
You will need a press for the bushes.
Swivel bearings can be adjusted by removing shims. To physically check the bearings requires a bit of dismantling.
If your D1 is not your daily driver then give it a go.

P.M your vin number and I'll find some part numbers for you.

Originally Posted by BigJon

I think you are arguing over semantics. For the sake of clarity I think it is entirely reasonable to refer to toe adjustment as wheel alignment.

No it's not, if you adjust the toe in/out, unless you have them dead straight ahead then toe in/out is actually un-aligning the wheels. Adjusting caster and camber is done to ensure correct steering geometry, return to centre after turning (Ackerman) and stability and alignment with rear wheels. So if you want to pay a wheel aligner to adjust your toe in/out and pay the same as you would pay for a proper wheel alignment, then go ahead, Regards Frank.