Rear subframe corrosion

[Barmac]

I'm afraid that our 2005 400h has failed MOT on the above. I recall one of our members was looking at fitting a used subframe to his RX due to the same problem, but I can't find a write up on the job.

Has anyone attempted to replace a rear subframe? Is it a job that can be done "at home"? My son is a BMW technician so access to tools shouldn't be a problem, and we have a reasonable skill level but no Lexus experience.

 

Any thoughts please?

[Herbie]

Barry, I've just sent you a PM which may be helpful to you.

[PCM]

My RX failed a year back... subframe corrosion.

Welding cost about £150 and fixed it.

[Barmac]

Thanks for the information Herbie; you are a mine of useful stuff!

I'd hoped that welding might be an option Piers but I am concerned that it's too far gone.

We've owned the car from new and so we're in the "worth more to us than anyone else" scenario!

Thanks again for your help.

Kind regards,

Barry

[welland]

On 10/31/2020 at 8:33 AM, PCM said:

My RX failed a year back... subframe corrosion.

Welding cost about £150 and fixed it.

My garage has just noticed a small hole in the rear sub frame on my rx400h.  I haven't seen it  but it is apparently about the size of a thumb nail, and close-ish to a suspension bush ( I don't know how close)

It is booked in for welding in a couple of weeks, but they did not sound entirely confident of fixing it.  I think they were concerned about proximity to the bush, and also possible difficulty of finding good metal to weld to.  They did say it would be worthwhile to look in to getting another sub frame - if not for now, for the future.  

Has anybody here swapped a rear sub frame?  I would be interested in  hearing how much it cost: both time and parts.

[welland]

On 10/30/2020 at 6:09 PM, Herbie said:

Barry, I've just sent you a PM which may be helpful to you.

Hi Herbie,

May I have the details that you sent to Barry, please?

[Herbie]

5 minutes ago, welland said:

Hi Herbie,

May I have the details that you sent to Barry, please?

Just PM'd you now Peter.

[Spudd]

Anyone have an idea where i can get a rear subframe for future use.

[Russell Wheeler]

I would try eBay, there are a number of cars being broken on there. My car had advisories for corrosion, and looking the front subframe is very rusty. I have started to use waxoyl to prevent further rusting, and in spring will go through the entire underside. Not very good considering it has been main dealer serviced since new.  https://www.ebay.co.uk/itm/BREAKING-LEXUS-RX400H-RX300-2004-2009-HYBRID-SUPPLY-OF-ONE-WHEEL-NUT/154212152401?hash=item23e7c2b451:g:xL4AAOSwM81eKYTT

[Barmac]

Just for information, having looked at the situation in more detail (thanks again Herbie), we concluded that dropping the subframe sufficiently to enable welding on both sides of the corrosion was the way to go. We then cleaned up all of the underside and waxoyled to hopefully delay any further issue. Seemed like an easier option than replacing the subframe. My advice would be to check for corrosion regularly to hopefully prevent it getting to the stage where MOT failure is an issue. Classic case of do as I say rather than do as I did! 

[Barry14UK]

12 minutes ago, Barmac said:

Just for information, having looked at the situation in more detail (thanks again Herbie), we concluded that dropping the subframe sufficiently to enable welding on both sides of the corrosion was the way to go. We then cleaned up all of the underside and waxoyled to hopefully delay any further issue. Seemed like an easier option than replacing the subframe. My advice would be to check for corrosion regularly to hopefully prevent it getting to the stage where MOT failure is an issue. Classic case of do as I say rather than do as I did! 

A regular check of the underside and taking pro active measures to delay corrosion indeed sensible.  As the old maxim states, 'Prevention is better than cure'.