LS430 transmission failure - total fluid loss

[polymoog]

6 minutes ago, GrahamG said:

If a second hand tranny could be installed for say £1600 

From what I've gathered so far a used tranny is about £450 and fitting time is 3-4 hours, so should be well under £1K from an indy specialist. Extra work to rads, pipework etc will bump that up of course.

[sorcerer]

30 minutes ago, GrahamG said:

Their master technician with Lexus 10 years reports he does know of this problem [water from rad into gearbox] but that it is very rare.

This isn't just a Lexus thing. Many cars have pipes taking transmission fluid through the rad to cool it, including my old Nissan Maxima and Nissan Maxima QX to name just two. If I remember right, my old Rover 800 Sterling also had this arrangement

It's a poor design as, sooner or later, most will corrode to some extent.

[Malc]

this radiator cost seems a bit dopey ............  the many posts on various bits and pieces here gave me the impression prior that the perfectly adequate non Lexus new radiators can be bought for sensible money and do a good job at preventing this unfortunate gearbox failure arising.

There didn't seem, amongst the Posters,  any need for a genuine Lexus radiator at all .......  

Malc

[sorcerer]

50 minutes ago, Malc said:

There didn't seem, amongst the Posters,  any need for a genuine Lexus radiator at all

That's correct, there isn't.

All radiators that have transmission oil-cooling pipework in them, are equally at risk of failure and possibly allowing transmission fluid to enter the cooling system and/or coolant to enter the transmission, irrespective of who manufactures them,. It's a silly design really but it's used by many car manufacturers.

The only way to be sure of avoiding an expensive disaster is preventative maintenance. As soon as you begin to see any signs of corrosion on the pipework that's more than just a bit of surface rust, change the radiator - and you may as well use a cheapy third-party one because you may have to do it again if the car is long-lived.

[The-Acre]

40 minutes ago, sorcerer said:

That's correct, there isn't.

All radiators that have transmission oil-cooling pipework in them, are equally at risk of failure and possibly allowing transmission fluid to enter the cooling system and/or coolant to enter the transmission, irrespective of who manufactures them,. It's a silly design really but it's used by many car manufacturers.

The only way to be sure of avoiding an expensive disaster is preventative maintenance. As soon as you begin to see any signs of corrosion on the pipework that's more than just a bit of surface rust, change the radiator - and you may as well use a cheapy third-party one because you may have to do it again if the car is long-lived.

About £85 it cost to replace the radiator on both my LS430's. It would be possible just to take the old one out and clean the joints and put in new O rings as that's where the problem begins, but as they're so cheap it's easier just to put in a new one. A slight adaption is needed however as the after market ones are slightly different.

[polymoog]

All well and good for those in the know with thousands of Lexus-related posts to their name, but for the rest of us when your garage calls to say the £120 after-market rad they've received is 'the wrong one' - presumably because it doesn't have the remote filler - and the only place they can find the 'right one' is at Lexus, then one is over a barrel. I'm not an expert in Lexus radiators or where to source the various types or how to adapt the 'wrong one'. 

My garage sent mine for assessment to be re-cored and otherwise patched up. It was concluded it couldn't be done for less than the cost of a new Lexus rad.

I tried Paul Frost yesterday and he didn't have the remote-filler version available.

So what can I do? The car is sitting at the transmission specialist taking up space and they want a decision on whether to proceed. One can only decide with the information one gets from those who you have to presume know what they're talking about.

Cheers.

[cruisermark]

Here is  a link to phils post when he replaced his - he bought it from Euro Car Parts - He also mentions the slight mod required - perhaps your garage could take a look

 

[polymoog]

Just had word from the specialist: car is all back together and the transmission is fine - "drives beautifully".

Assuming it holds up I've dodged a bullet there I reckon. Or should I say it's just a flesh wound :)

 

[The-Acre]

7 minutes ago, polymoog said:

Just had word from the specialist: car is all back together and the transmission is fine - "drives beautifully".

Assuming it holds up I've dodged a bullet there I reckon. Or should I say it's just a flesh wound :)

 

Brilliant news!

[RgrWynne]

Just had word from the specialist: car is all back together and the transmission is fine - "drives beautifully".

Assuming it holds up I've dodged a bullet there I reckon. Or should I say it's just a flesh wound :)

Really pleased for you, have many more miles of happy motoring, Cheers, Roger

 

[RgrWynne]

&

On 6/7/2018 at 9:06 PM, sorcerer said:

 

All radiators that have transmission oil-cooling pipework in them, are equally at risk of failure and possibly allowing transmission fluid to enter the cooling system and/or coolant to enter the transmission, irrespective of who manufactures them,. It's a silly design really but it's used by many car manufacturers.

The only way to be sure of avoiding an expensive disaster is preventative maintenance. As soon as you begin to see any signs of corrosion on the pipework that's more than just a bit of surface rust, change the radiator - and you may as well use a cheapy third-party one because you may have to do it again if the car is long-lived.

I would agree that at the first sign of corrosion to change the rad. I think the problem is , is that the corrosion is internal and not visible, and therefore prevention at a set time is probably wise. From Lexus dealers point of view this is very rare, but from reading on this forum you would not think so. I took the view to change, and there was no sign of any corrosion at all after 16 years. Having said that it gives me peace of mind and I am glad I did, and it would appear my Lexus OEM part was a bargain.  Cheers, Roger

 

[sorcerer]

52 minutes ago, polymoog said:

Just had word from the specialist: car is all back together and the transmission is fine - "drives beautifully".

Assuming it holds up I've dodged a bullet there I reckon. Or should I say it's just a flesh wound :)
 

Excellent news!!

So what happened rad-wise in the end? Did you show your garage the post about how to modify an aftermarket rad or did you go for an OEM one?

[polymoog]

8 minutes ago, sorcerer said:

Excellent news!!

So what happened rad-wise in the end? Did you show your garage the post about how to modify an aftermarket rad or did you go for an OEM one?

They'd already ordered in the OEM one and wanted to crack on with the job (if you recall after getting a cheapy and returning it after being foxed by it being different) and they didn't seem keen on trying for a 3rd one, so I let them stick with the Lexus part. An extra £150 but I'd lost the will to try and change their minds by that point so it was a case of JFDI.

[Haylands]

Missed this post... sorry for that... 

I am sure your box will be fine and have no lasting damage, you were lucky that it dumped all the oil out of the box, the issue that ruins the box is when the coolant from the radiator enters the gearbox and gets pumped around for a period of time (maybe even 100's of miles) reducing the ability of the gearbox oil, the clutches will wear rapidly and you lose drive due to an inability of the clutches to supply drive, the gearbox is then toast. You lost drive because the torque converter ran out of fluid and stopped turning the gearbox...

 

IMHO the "BEST" answer and prevention for this is the one you are happy with... change the rad and the pipes and you are good to go for another 8+ years....or..... add a remote cooler....

 

The replacement cooler will cool the gearbox oil to a sufficient degree, the ideal gearbox oil temperature will be around 90c, it can reach 170c+ inside the torque converter when doing grand prix starts or driving up steep hills for a protracted time, or towing a heavy trailer or caravan (Not likely in a 430..!!) Most of the time the gearbox oil will be within spec and no cooling will be needed, Lexus have to respond to all sorts of abusive driving as well as very hot climates so they fit a rad... Is it really needed by "most" drivers in this country...??? probably not... The replacement coolers can be screwed to the bottom of the front aluminum bumper support, this gives them a very large heat sink and they will dissipate the heat just fine. The only downside I can see is that the original system will actually heat up the oil to operating temp quicker in the depths of winter whereas the replacement won't. I think the difference would only be a few miles of driving though...

A replacement radiator, keeping on top of coolant changes, and regular checking of the pipes is fine as well, and keeps the car original

BUT... if left alone the original setup will fail, if you are lucky it will cost you a radiator and some pipes, if not you are looking at a new gearbox... some have stated the engine could overheat and be damaged as well but I think that is not going to happen, you will lose drive because of water in the gearbox before the reduction of water in the engines cooling system damages the engine.

So... what to do... as I said earlier the best solution is the one you are happy with....

Me? I have a replacement oil cooler and lines sat in the garage that will be fitted next week...

Just my 2p...!!

 

[GrahamG]

Peter, 

Let me compliment you on a well reasoned and balanced post.

A few days ago I was all set to buy a separate rad but was put off by the argument that the original design provides preheating in the winter.

The solution that works for me is to do nothing because I could have the car trucked up to Paul Frost to fit a second hand tranny at a cost that does not justify the preventative maintenance of a Lexus rad. Bearing in mind my low mileage is all local and I will not be stranded in some exotic location.

As you say, just my 2p.

 

[The-Acre]

6 minutes ago, GrahamG said:

Peter, 

Let me compliment you on a well reasoned and balanced post.

A few days ago I was all set to buy a separate rad but was put off by the argument that the original design provides preheating in the winter.

The solution that works for me is to do nothing because I could have the car trucked up to Paul Frost to fit a second hand tranny at a cost that does not justify the preventative maintenance of a Lexus rad. Bearing in mind my low mileage is all local and I will not be stranded in some exotic location.

As you say, just my 2p.

 

I know I've posted this in the past but it's worth putting on again.  This was the the connection from the radiator to the transmission hoses on my first LS430, it's easy to see from this where the problem begins, corrosion breaking the seal.   It's a shame it wasn't all made from stainless steel.  The cooler within the radiator is aluminium  and was like new when I broke it apart.  It's just these two connections that are to blame which is why I think another preventative measure could be taking the joints apart, cleaning and re-fitting, that'll save replacing the rad altogether.

 

[GrahamG]

Phil,

Thanks for offering an alternative opportunity to be pro active against this problem and which leaves the original design intact. 

It is especially appealing to me because my car has a full main agent service history and with the correct coolant in the system and only 80,000 miles I did wonder if an after market rad might not be a retrograde step.

There is near me someone who has an excellent reputation for repairing , building and designing rads so I might involve him.

[The-Acre]

27 minutes ago, GrahamG said:

Phil,

Thanks for offering an alternative opportunity to be pro active against this problem and which leaves the original design intact. 

It is especially appealing to me because my car has a full main agent service history and with the correct coolant in the system and only 80,000 miles I did wonder if an after market rad might not be a retrograde step.

There is near me someone who has an excellent reputation for repairing , building and designing rads so I might involve him.

It does mean removing the rad if a ramp isn't available to do it underneath.  Also a word of warning, do one side at a time because the two unions are the only thing holding the cooler in place, there are two o rings on each joint, one as seen in the photo, the other visible when the connection is removed.

[GrahamG]

Phil, 

I am sure it is all quite simple but I cannot exactly visualise the set up. 

Given access to a ramp I leave the rad in situ but do we need to drain the coolant to inspect the suspect unions? Is it just the unions that cause the problem?

Assuming the metal of the unions is not corroded would we expect to just renew 4 'O' rings and reassemble? The union in your photo does not look bad to me.

I believe so little ATF is lost it would not be necessary to top up.

[The-Acre]

2 hours ago, GrahamG said:

Phil, 

I am sure it is all quite simple but I cannot exactly visualise the set up. 

Given access to a ramp I leave the rad in situ but do we need to drain the coolant to inspect the suspect unions? Is it just the unions that cause the problem?

Assuming the metal of the unions is not corroded would we expect to just renew 4 'O' rings and reassemble? The union in your photo does not look bad to me.

I believe so little ATF is lost it would not be necessary to top up.

It's worth pointing out that mine hadn't failed, I only replaced the radiator as a precaution after reading about the possible problem.  You can see the rust beginning on mine and I believe it's the spread of rust that causes the joint to fail, that perhaps coupled with the slow failure of the o rings (as used to happen with the early LS400 power steering pump)

Here are some more photos that I think show the real possibility of impending doom!

The first is the radiator upside down showing the two connections that join the transmission via the rubber hoses, easy to access from underneath if raised up, the second is the bottom of the radiator cut away showing the cooler, the third shows just the cooler separated and how things were deteriorating.   As you can see, the cooler is actually very small but in perfect condition in itself. And yes, the coolant needs to be drained but you don't really loose trans fluid, just a tiny amount.

[polymoog]

Been away so only went to collect the car today. I got literally two miles down the road before the transmission failed and I lost all drive.

I'm now drinking beer.

[sorcerer]

Good that you're drinking beer, sad about the car.

Drink more beer!

[GrahamG]

You must be well and truly fed up with the whole thing.

Am I correct in thinking Paul Frost installs second hand transmissions as well as selling them?

In which case would trucking it to him be an option?

[The-Acre]

1 hour ago, polymoog said:

Been away so only went to collect the car today. I got literally two miles down the road before the transmission failed and I lost all drive.

I'm now drinking beer.

You must be so gutted, I really feel for you.

[polymoog]

13 hours ago, GrahamG said:

You must be well and truly fed up with the whole thing.

Am I correct in thinking Paul Frost installs second hand transmissions as well as selling them?

In which case would trucking it to him be an option?

Yes it's very dispiriting, although I knew there was a risk - make that likelihood - that all wouldn't be well at this stage.

The guys it's with at the minute could fit one of Paul's transmissions, if I decide to throw more money at it.