LS400 Axle subframe / assembly

[Swan55]

Hello,

We have a 1998 LS400 with 160,000 miles

Our MOT mechanic is really unhappy about the amount of rust at the back and wants us to get a replacement rear axle assembly / subframe, which he also calls a 'bed'.

Has anybody got any experience of this ?

thanks

[dendonc]

45 minutes ago, Swan55 said:

replacement rear axle assembly / subframe, which he also calls a 'bed'.

Has anybody got any experience of this ?

I haven't but I have experience of buying Lexus parts from Lexus & what you mention is needed is going to cost a very, very big packet if you get the from Lexus thats for sure!

[ambermarine]

The rear subframe for the Mark 4 is expensive from Lexus and cannot be obtained from aftermarket suppliers,your best option is a breaker such as Paul Frost who specializes in used Lexus parts.

Your Mechanic needs to give you a price for fitting  before you set about getting a replacement subframe because its not a small job and my guess is you will need a few other replacement bushes and control arms by the time he as taken the subframe off the car.

[dendonc]

I had a very similar dilema earlies this year with a control arm gone, that in itself was not the main problem, the main problem was the same as yours (probably) rust & some corrosion, only one decision to make, breakers, end of, got another LS400. I had a great just under 50,000k miles out of it, it only cost 900 quid in 2011 when I got it, but, with rust/corrosion it had to go, now....I've got this at 159k miles but 1800 quid.................its hard to say good bye but a greater delight to say hello!

[Tinonline]

Is it surface rust or real corrosion?

I’m surprised given Lexus build quality you are experiencing this. Bodywork can get caught but major structure in quality cars is a bit unusual.

[dendonc]

On 6/9/2018 at 9:46 PM, Tinonline said:

Is it surface rust or real corrosion?

I’m surprised given Lexus build quality you are experiencing this. Bodywork can get caught but major structure in quality cars is a bit unusual.

It's stuff written on the MOT advisories when/if they write it on, problem with advisories they do not have to write them on at all or in full, corrosion is a common issue in the LS & for all I know many others, lexus or otherwise.

Also, if you do some DVLA MOT history checks of 18+ years old used LS 400's for sale today-tomorow? you will probably find the majority have some corrosion issues, it made me wonder earlier this year if thats why several ads had their numbers blacked out, cant see any other reason for doing that.

First one i tried, no morning time to look a more...coil springs corrosion

https://www.ebay.co.uk/itm/Lexus-LS400-Mk4-Xenon-headlights-strait-pipe-V8-Monster/302738852043?hash=item467ca448cb:g:Hf0AAOSwx6Za-fdT

[runsgrateasanut]

Is this a by-product of the new MOT rules?  Are Garages going to suggest major expense needs to be done where perhaps surface or small amounts of rust are visible? Is it going to fall into the "dangerous" category?  Depriving owners of doing their own work although I read that you can take a Car away from the Garage.  Not yet tested as to legality. How the Government plans to get older Cars off the Road, I suspect.

 

[dendonc]

53 minutes ago, runsgrateasanut said:

Are Garages going to suggest major expense needs to be done where perhaps surface or small amounts of rust are visible?

Very good point, almost a certainty some places will do that

[Newbie1]

Compared to the rest of the structure it's a bit of a weak point, as it is on Soarers and other Toyota rear wheel drive cars of the era. At this age, like any car that's been exposed to salted roads, the underbody needs careful attention. Mine was in good order so I had it undersealed, with particular attention to the rear subframe. Even then, rust never sleeps.

[steve2006]

Do you have any pictures of the subframe as it would be interesting to see the extent of the rust, my 1994 spent its first 12 years in Japan so was virtually like new underneath when brought into the UK and has since been treated to preserve it. On the other hand my UK 1999 model is a complete rot box underneath with completely rotten brake disc covers and extensive rust on the rear subframe TBH it looks like it was stored in a field!

Recently I have seen pictures of sill rot below the rear doors to the wheel arch area on the LS400s, those plastic panels can hide a lot of problems!

 

[Swan55]

Thank you all for your replies.

We're currently talking to Paul Frost (lexussparesdirect). He has been very good with advice and suggestions and I hope we can do a deal.

In addition we'll need the relevant control arms etc. but paradoxically it may turn out to be easier / quicker to replace the whole lot as a unit rather then some bits this year and some next year etc.

 

Tinonline: its beyond just the surface and a few holes have appeared here and there. I suspect the tester may be being a bit cautious, but then it is a heavy car with a fair bit of power going to the back wheels; and next year I don't imagine spare parts prices and availability will be any better.

runsgrateasanut: new mot rules "dangerous", I also suspect some places will start incorporating this into their practices; and gov't "unintended consequences" will result in older cars quietly going away - "because their old and dangerous gas guzzlers etc etc." (meanwhile our mechanic tells me of the numerous gearbox failures he's seeing with 'modern' cars that have only done 11,000  20,000  26,000 miles  (mainly KA, clio, fiat 500)).

Ambermarine: thanks for Paul Frost suggestion, saved me so much time looking elsewhere - which was getting me nowhere.

Steve: No photos yet, but will try and get some when she goes back up on the lift.

Denis: nice car, same blue as mine ("S" reg), except your seems much cleaner !

I think when the existing parts are off, it will be a good time to underseal everything in sight, before the replacement bits go back on.

many thanks,

 

 

[Ac1978]

I’ve got the sill cladding off mine at the moment,I found a pile of damp mud had collected just in front of the wheel arches on both sides and it’s just started to eat away at the sill.

Hopefully I’ve caught it just in time,I’ve treated it and sprayed it up.

The problem is where the sill cladding meets the wheel arch the gap there let’s dirt in where it can sit between the cladding and the sill.

The cladding is a pain to remove and I broke most of the clips underneath,but if you do this it might just save your sill from rotting out.

The rear sub frame and suspension are also quite rusty on mine but it’s a 1996 and unless they have been really looked after or locked away in a garage it’s inevitable.Shot blasting,rust treatment and powder coating the subframe should get many more years from it.

The design of the ls400 with the plastic cladding is very close to the Mercedes of that era and the mercs rust must more quickly,I’ve read that this is because they changed to water based paint.I don’t know if Lexus used water based paint but if they did is was applied much better than Mercedes.