rx400 rear sub frame (mot advisory)

[rog99]

Hello

RX400h, owned by me for 7 years, currently around 160k on the clock. Just had its MOT recently and received an advisory about corrosion on the rear sub frame. My local garage (independent who do all my maintenance and MOT) have suggested this is likely to be an issue come next the MOT, and that there are no pattern parts available, and Lexus charge over £1k for the part 🙄. My garage estimate labour could be 5 hours as there's a lot of faffing around and bits to remove/put back etc.

I've used this garage for the last 15 years and trust their judgement, and that they are honest with me also. They have done welding on the car I had prior to the RX, however they didn't suggest that this time - which either makes me think they can't do it, or would rather not (I understand from various forums i've read the last few days that depending on where the corrosion is, welding may be tricky without causing damage).

I guess it's just reached that age now where things start wearing out (a bit like me!). Unfortunately i've spent a few £K on it in the last 12-18 months; full set of new radiators and aircon overhaul, some suspension-related items and brake discs/pads, etc.

Ironically I often joke that it would be nice to change car but the RX doesn't seem to wear out (cosmetically and driving wise the car seems the same as it was when i bought it 7 years ago!). However i was hoping to keep it another 2-3 years before changing - having 2nd thoughts now. Since CV19 my job role is now home based, so my annual mileage is maybe 3000/yr. Another reason I wasn't rushing to change car to have something 'newer' simply sat on the driveway most of the time...but I like the comfort of the Lexus so don't think I could go back to driving bangers as I used to 15-20 years ago. Also currently a single-car household so need reliability.

I think the best way to sort the RX ahead of the next MOT would be a sub frame from the breakers yard. Slight concern is those would be a similar age so may also be in a similar condition (as mine is a 2008 so one of the last RX400 before they introduced the 450s). Always the risk that something else substantial ££ will also wear out 12 months from now. I always have repairs/maintenance done whenever things come up, however it does feel like it has been a few years since i've had a 'cheap' MOT 🙃

How much do we think this MOT advisory will put off potential buyers (or reduce the sale price)? As I wasn't planning on selling yet I haven't yet looked what the car is actually worth even before that is factored in.

Looking for some opinions and suggestions from anyone who has been in a similar position.

 

[Russell Wheeler]

I had the same this year, on both subframes at MOT. It was on the ramp and I had a chat (and look) with the mechanic carrying out the mot repairs. It is rusty, but surface rust, so would last years. I will treat the subframes with rustproofing next year when it warms up. Second hand ones are available, get them cleaned up and rustproofed when you purchase them.

[katabrontes]

This is interesting.  It's the second recent report of serious rust on RX400 subframes. My RX350 is also 2006 but no report of any corrosion on the underneath at last few MOTs.  Just a slightly worn bush.  Is the underbody protection poor on the 400 and improved on 350/450?

[Barry14UK]

This situation has been brought up by others in the last year or so and you believe your garage are honest having looked after the maintenance of your car for some time.  In your shoes, I would discuss with them whether they could weld up and treat the affected sub frame so it would give another say 5 or so years and if so at what cost.  Alternatively, if they don't want to do this job, could they recommend somebody who could.  You could also check meanwhile what you could get a reasonable second hand one that would require minimum work would cost.  In either event the existing subframe would have to be removed and you will have an idea of the cost due to the time indicated by your garage.  

You can then consider whether the cost is worth it to you.  A replacement car of the same quality may need a lot of work but you know with the service and work done on yours that you have a car that should only require minimal maintenance.  However. I would also get a report as to the likely need that the other subframe might need repair/replacement over 5 or so years or you may be back in a similar situation again.

Good luck.

[Malc]

8 hours ago, Barry14UK said:

repair/replacement over 5 or so years or you may be back in a similar situation again.

5 years future horizon is a very long time in the life of a car ............  even the owner too ....... even simple accidents that can write a car off by insurers ....

My view is that if it is repairable at some sensible cost and can be, howsoever it's achieved, and you really have confidence in this car then I would bite the bullet and keep it on the road ............ the next one you buy could be someone else's imminent problem they too are trying to get rid of

after all, you're only covering 3k miles a year now !

Malc

[rog99]

Lots of good replies here, thank you all.

My initial thought was 'I will have to change the car before the next MOT' but having slept on it, and read the wisdom in the above responses, i'm now leaning towards 'lets find out the actual cost to fix/replace it, and assess any other potential upcoming maintenance items, then make a decision'.

As one response pointed out, given the mileage I do, the cost of repair is likely going to be lower than buying an 'unknown' 2nd hand car instead, providing the above leg work is done first to ensure there no other surprises on the horizon.

Not knowing much about metal work, i presume a replacement part from a breakers etc could have some sort of rust-treatment done to it before fitting (and that would obviously be the easiest time to do such a thing, as easier to get to etc). Is this like a paint type thing I could apply myself once i source the parts, or would I need to take that to someone (i'm handy with tools generally, just not so much with car-things!) ?

 

[kenhall]

There is a decent looking RX400h subframe for sale on eBay from a Lithuanian seller for £120 +60 delivery (or offers). They made me an offer of 10% off (£12).

https://www.ebay.co.uk/itm/255254244063?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

If I was in your position and keen to keep the RX long term then I would go down the route of corrosion proofing the used subframe after stripping it back to bare metal ( don’t know if hot dip galvanising is a possible option) and then performing a swop with the corroded subframe.

Edited December 6, 2021 by kenhall
Detail added

[plastic orange]

Our RX 300 and my Daughter in laws one of the same age looked pretty shabby underneath, despite us coating them with Bilt Hamber products when we bought them about 5 years previously. However, only comments on MOT was regarding the copious amount of bilt hamber product on underside lol. On our one, all the mounting points for the undertrays were unserviceable, and one support had to be removed due to terminal rot (not an mot fail though). Our solution to the issue was to move them both on and we bought newer vehicles, but not lexus. Strangely, both ended up in the same dealer down south despite us trading them into different garages. I'm assuming they were sold at auction and bought by the dealer down south. I'd guess both have limited life left in them due to corrosion, but mechanically and looks wise they were nice cars. It's a pity that Lexus don't protect their cars better in this regard.

Incidentally, when we bought them, they were the best condition ones we could find, I looked at some horrors. We are both happy with our newer vehicles and to date they have proved cheaper to run than the RX's, plus in the current climate worth a good bit more than what we paid.

 

Pete

[kenhall]

https://www.ebay.co.uk/itm/255254244063?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649&utm_source=LexusOwnersClubUK&utm_medium=ForumLinks

I see someone bought this subframe for £120 delivered- anyone on the forum?