Corrosion on rear axle, anyone seen this before?

[valmiki]

Hi, Car went for service yesterday, horrendous news, extensive corrosion on rear axle.

 

 

No sign of corrosion the year before so this came round pretty quick! 2010 Gen3 Prius, 120K miles

What does everyone think, time to get rid? 

[Chris Dance]

I am surprised to see that. My son recently sold his 2010 Prius and it was pristine underneath. Has your car been driven on a beach or stored in salt water area? Was your car regularly serviced by Toyota?

[TonyHSD]

Lol, that is really bad shape. Definitely been there before last year but somehow not as noticeable and perhaps not a hole in. Best to,have it replaced with another axle beam from salvage car, just make sure is not as bad. Usually things like that happening and rust in general on cars that been used irregularly but some of these times they had been taken to the motorway during winter months when gritted and salted , add the rain that we have and the combination is worse than if you could have drive through the sea. Only to blame uk government and councils who have that bright idea to salt to roads when there is no real danger of ice, or anything, just destroying peoples properties., and the roads too. 

[APS]

Wow! Not seen one with actual holes in it. Are you near the coast perhaps? The salt in the air can be exceptionally aggressive.

I once bought a car with low miles that had lived not far from the coast and you didn't need a prop for the bonnet as the hinges were so seized up!

Anyway, those torsion beams can hold dirt and moisture which accelerates the rot. I'm sure there are plenty of second hand ones. I don't think it's a 'known issue'. 

[Bernard Foy]

36 minutes ago, TonyHSD said:

Lol, that is really bad shape. Definitely been there before last year but somehow not as noticeable and perhaps not a hole in. Best to,have it replaced with another axle beam from salvage car, just make sure is not as bad. Usually things like that happening and rust in general on cars that been used irregularly but some of these times they had been taken to the motorway during winter months when gritted and salted , add the rain that we have and the combination is worse than if you could have drive through the sea. Only to blame uk government and councils who have that bright idea to salt to roads when there is no real danger of ice, or anything, just destroying peoples properties., and the roads too. 

Wow horrible and unsafe, might not be easy to source a good used replacement. It should be a lesson to us all to power wash underneath our cars two or three times in the winter months. Road salt definitely a scourge.

[valmiki]

Yeah, came as a bit of a shock, particularly as it flew through the service and MOT last year! Serviced religiously by the local Toyota garage too. I’ve been advised replacing the rear axle is an option (obviously not cost effective via Toyota) but will almost likely bring other issues, brake pipes etc.  

I do live near the coast but I’m not aware of other cars I’ve had being so badly affected because of it. I was asked if it had been sat around for long due to lockdown, but the car was in use every day (or thereabouts) so that doesn’t seem a likely reason either. 

[TonyHSD]

My car gets a lot of salt doing long motorway journeys every night and especially the times when gritters are out and about and spreading like it’s end of the world🤭, I do wash every two weeks and try to spray as much water as possible under the car, inside wheel arches and suspension parts, brakes etc. But even not washing it it’s still better than many cars that only came out on the salty roads once or twice and then been left without regular use , as if been used regularly and on motorways after the salty period when the spring rain cleans the motorway a good high speed run on rainy day on the motorway will properly clean the underbody and suspension, those cars who missed that wash or car wash underneath rust the most. I know that from personal experience with my own cars. 

[APS]

4 hours ago, valmiki said:

Yeah, came as a bit of a shock, particularly as it flew through the service and MOT last year! Serviced religiously by the local Toyota garage too. I’ve been advised replacing the rear axle is an option (obviously not cost effective via Toyota) but will almost likely bring other issues, brake pipes etc.  

I do live near the coast but I’m not aware of other cars I’ve had being so badly affected because of it. I was asked if it had been sat around for long due to lockdown, but the car was in use every day (or thereabouts) so that doesn’t seem a likely reason either. 

Yeah, that's worrying as this is not something that develops over a single year. 

Looking at the corrosion in your photo I stand by my first assessment that this is caused by acidic corrosion - probably a result of a combination of sea salt and road salt. The pitting that's shown on the vertical part of the suspension arm is typical. I bet if you hammer at it, it will feel pretty solid but eventually break off revealing black rust. 

 

I'm sure it's perfectly fixable. But I can also imagine that all the nuts and bolts may also be quite nicely stuck, making the work that little bit extra "enjoyable". Keep us posted. 

[TonyHSD]

https://www.ebay.co.uk/itm/TOYOTA-PRIUS-1-8-PETROL-AUTO-2009-2010-2011-2012-2013-REAR-AXLE-BEAM-/254561362310?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=710-127635-2958-0
 

it seems eBay vendor sells even a brand new one but not original and I will probably go with that used in good shape instead. 👍

[QuantumFireball]

Mine looks a bit crusty around that area but certainly not that bad! 😳

Anyone have any recommendations regarding Waxoyl or other treatments?

[flash22]

Had the car long ? Do you live on the coast ? the welsh coast isnt easy on cars, even higher elevation inland get a blasting from the sea

6 minutes ago, QuantumFireball said:

Mine looks a bit crusty around that area but certainly not that bad! 😳

Anyone have any recommendations regarding Waxoyl or other treatments?

Bilt Hamber do some very good products - clean, rust convert and coat

https://bilthamber.com/

[valmiki]

I do live near the coast, though I'm sure that wasn't the direct reason. 

About 7-8 years ago (for a period of 18 months or so), my offices were next to the beach. The staff car park frequently got blown over by sand and there would periods of high wind where sand would be blown all over the place. While I would make sure the car was washed very regularly, the underside wouldn't have had the same frequent attention. Looking back, I can only think this is the reason.

Sadly the car is going. I've managed to get a reasonable price and thankfully I have use of another car for a few months.

[GingaPete]

Same thing happen to my Prius last week. 2009 model. Bought with 44k on the clock. Had it a few years. Died at 125k when the 'unusual corrosion' spotted at the MOT (last one in July!) gave way, luckily not on the motorway! Rear passenger wheel axle became unattached from the car and rammed into the wheel arch. Scrap! Would like to buy another Prius, but my trust and wallet is badly dented.

[GingaPete]

My Prius died last week. 2009 model. Bought with 44k on the clock. Had it a few years. 125k on the clock. 'Rear subframe and underside unusual corrosion spotted' at the 2018 MOT at 42k miles. Last MOT was July 2023, 'Rear axle corroded' and 'Underbody corrosion' advisories. Gave way last week, luckily not on the motorway! Rear passenger wheel axle became unattached from the car and rammed into the wheel arch. Scrap! Would like to buy another Prius, but my trust and wallet is badly dented.

[FROSTYBALLS]

Similar topics merged

[valmiki]

If it's any consolation, I recently looked up my Prius. It was fixed and back on the road, last MOT was on 164k!

[APS]

Thanks for thew followup. Good to hear it's still on the road. Have you taken any preventative measures on your new car? The rust on your old Prius certainly looked very salt induced. Chances are that where you live is pretty harsh on cars.

[valmiki]

No, I haven't. This was a first after 30 years of driving! I'm convinced this was a one-off, as I mentioned before due to a very windy and sandy workplace car park. Thankfully I left there a few years ago but sadly the effects on the Prius didn't.

My wife bought a new CH-R recently so I have jumped into her previous 2012 Auris Hybrid, on around 75k. Not seen any issues so far, and I am having it serviced at a regular garage rather than the dealer, primarily as there's no use paying for a 10 year warranty at their prices when I can't use it.

Next service I'll be asking the garage to have a proper look at suspension components as I plan to keep it for a couple more years.

 

[Bernard Foy]

It goes without saying that it would have been prudent to have given it a good check over before you bought it given your experience with your previous one.

[valmiki]

It was brand new

[TonyHSD]

This corrosion issues aren’t just happening in one or two years time , the problem has had started long ago however the garages who were maintaining and servicing the cars were not thoroughly checked them. If they were and these issues spited on time , noted and repaired those cars now could still be on the road and serve you well. 
Another reason for this excess corrosion is minimal or lack of maintenance during winter months either by the previous owners. Drive the car when cold and salt is on the road and then if you not gonna drive again for a week , before you park and leave the car visit car wash or wash yourself as much as you can undercarriage, wheel arches, suspension parts, brakes , all these otherwise will remain covered in salt water which will accelerate corrosion 10 times faster.