Knock at the front

[Daveyboy20]

Hi guys, my 98 LS400 is beginning to develop a slight knock at the front over bumps. I have about 4 months until mot time so thought I'd do the ground work now.  I'm assuming it's going to be a bush in either a top or bottom arm? I've read a few issues with rubbish eBay parts and a lack of decent parts available. What are my best options?  

[Malc]

what's the mileage on your car ?

My nearside front UCA had to be replaced at about 173k miles, the offside is still seemingly quite ok at 206k miles  ☺️ 

Miles and road conditions play their part in wear and tear but our Ls components do seem to have longevity

Malc

[Daveyboy20]

Hmmm - mine's only on 118k, maybe I'm being paranoid! 

[Newbie1]

Had a knocking that went away after replacing the strut rods. Think you can get the bushes separately for those.

[steve2006]

Basically you will need to jack the front end up,get the wheel(s) off and pry bar every joint.

As already mentioned the favourite causes are upper ball joint (only complete arms available) and the lower ball joints both these are fairly easy to check with a pry bar used to see if the joints can be lifted slightly out of their respective sockets or there is visual evidence of damage like split rubber boots.

There are of cause plenty of other bushes like the lower control arm ones, anti roll bar bushes and steering rack bushes.

As for replacements if you can wait a few weeks amayama will supply all OEM parts from either the UAE or Japan, even with shipping and import duty these generally work out cheaper than UK Lexus prices ( the last time I looked a UCA was £521.00!). If you need the part numbers feel free to PM me your VIN. Lower ball joints were £120.00 a pair last time I needed some from Lexus UK, strangely Blueprint ones were more expensive.

 

[Mikaelse]

It is probably the strut rod bushings. they do not last. I changed these on a LS400 with only 100k mile on it and it fixed the klonk over road defects.
The old ones looked ok with some small cracks but were not. 
Now changing on my second LS400  year 2000.  same issue . Also "look ok" ca 110k miles on that one. 
I buy OEM Toyota/lexus bushings and press them in myself. ca 30£ each for the bushings shipped to sweden from AMAYAMA.  

Annoyingly the bolts are often seized or close to. A torch and compressed air tools may help but I cut them and bought new bolts. Another 40£

 

[Malc]

replacing the two drop link rods on the front made an immediate difference prior to doing all the UCA stuff  ( including replacing the BluePrint nearside UCA at 173k miles ) with both now replaced at, 218k with Amayama genuine Toyota parts

Malc