gearbox oil leak

[bordseye]

trying to do my "due diligence" before purchase, the only seemingly common issue mentioned to me, apart from some paint problems, has been that of the gearbox output shaft oil leak. Allegedly in some cases requiring a new gearbox at £27k a pop. Makes 430 manifolds look cheap!

Is this a common issue like 911 bore scoring. Or is it a rare issue. Has anyone here had this problem?

[CharlesElliott]

There’s a video on YouTube from Thorney Motorsport that covers this issue.

[PompeyReece]

It does happen but I remain unconvinced its a common issue enough to put you off buying it.

As the above post suggests, I think this is the Thorney Motorsport video which covers that and other McLaren topics:

https://www.youtube.com/watch?v=RGkswepyiDc

[12pack]

My personal (un)due diligence before going for a 650 spider concluded this was seen on the 12C and resolved by the time 650's ramped production. Less of a problem if the car was used at least weekly in any case.

[bordseye]

It was the thorney motorsport video that had me wondering, particularly the bit where it was mentioned that the cost of a gearbox was 27k. Eek!

Going back to what I said on another thread recently, it was the possibility of exhaust manifold problems that gave me disturbed nights with the 430 and they only cost 5k. Mind you it is a fairly common issue. Nevertheless I dont want to buy a McLaren and end up forever peering at the garage floor to see if there is an oil leak.

I wonder why it costs so much. I have happily replaced crankshaft oil seals on both cars and boats and its no big issue.

[tyrrell]

I’ll think you will find Thorney do the whole job for £9k inc VAT

[The Surveyor]

bordseye said:

I wonder why it costs so much. I have happily replaced crankshaft oil seals on both cars and boats and its no big issue.

The cost is based on a whole replacement gearbox, not a replacement seal. Because the gearbox is bought in as a unit from Graziano, if the seal fails McLaren simply replace the whole unit. If the seal fails whilst the car is under warranty, it costs the customer nothing.

Graziano wouldn't supply the seal separately (although I think that has changed which is why Thornley offer a repair) and for reference Graziano also supply gearboxes to Ferrari, Lamborghini, Audi, Maserati, Alfa Romeo and Aston Martin.

[bordseye]

Seals are like bearings. they are standard industrial items made in a range of sizes and available from your bearing factor. If I need a seal for my Volvo boat engine I dont go to Volvo I go to Seals Direct.

For that matter I am puzzled why McLaren replace the whole gearbox if there is a leak during warranty. Its a ridiculous way of going about things. Understandable with electronics with surface mount components but gearboxes are basic engineering not exotic.

[isaldiri]

bordseye said:

Seals are like bearings. they are standard industrial items made in a range of sizes and available from your bearing factor. If I need a seal for my Volvo boat engine I dont go to Volvo I go to Seals Direct.

For that matter I am puzzled why McLaren replace the whole gearbox if there is a leak during warranty. Its a ridiculous way of going about things. Understandable with electronics with surface mount components but gearboxes are basic engineering not exotic.

Very very few manufacturers don't replace the whole box rather than open it up. FerrariPorsche/Audi etc. everyone just replaces the whole box these days. Mclaren are not alone in doing so...

[The Surveyor]

bordseye said:

.....

For that matter I am puzzled why McLaren replace the whole gearbox if there is a leak during warranty. Its a ridiculous way of going about things. Understandable with electronics with surface mount components but gearboxes are basic engineering not exotic.

You appear puzzled by a lot of things... In simple terms McLaren don't make the gearbox (as explained earlier) and buy these in from Italy as a finished unit, so if there was a defect on a gearbox why would McLaren even consider repairing it when they can get the supplier to replace it. Why do you think it is a "ridiculous way of going about things" to simply pass the responsibility for the failure back to the original supplier?

I think you need to re-align your view on these modern twin-clutch gearboxes being 'basic engineering', they're not.

[12pack]

OP, sure sounds like you need a car with a full warranty that you are ok to pay for.

[bordseye]

isaldiri said:

Very very few manufacturers don't replace the whole box rather than open it up. FerrariPorsche/Audi etc. everyone just replaces the whole box these days. Mclaren are not alone in doing so...

I'd certainly expect that on minor components like a power steering pump, but even today I am surprised they throw away a £27k gearbox for want of a £3 seal. But then I guess an awful lot of modern technicians arent mechanics in the old school and only know how to replace full units.

The difficult bits about a twin clutch box arent the oily bits but the controlling electronics.

Anyway, none of this answers my question which is how common is the gearbox oil leak. Is it like Porker bore scoring? Or is it a pretty infrequent problem that was tackled by the time the 5 series came out?

Edited by bordseye on Friday 1st February 20:33

[tyrrell]

Let’s go round again

[Targarama]

bordseye - as has been said, this affected a very small number of early cars. Personally I've never heard of it on a Sports Series or 720 era model. I could be wrong but it seems to just affect early MP4/12C models. Most with any issue would be rectified by now anyway. This is really not a big issue. If you're that worried then stop repeatedly asking the question and buy something else. We all know Porsches and Ferraris hide similar bills from component failure.

[bordseye]

Thanks but only had a couple or people saying they think it isnt significant any longer and no one saying " I had it". But the Thorney video makes you think it might be common - after all they wouldnt bother to get a special component made just for a one or two off would they?

I'm not aware of a similar issue on Ferrari. The 430 manifolds are small beer by comparions cost wise. Yet you get lots of mentions of it on the forums but denial that it is at all common from the dealers. Who to believe - the forums where people post disasters not no-problems, or the dealers who are interested in minimising an issue.

Anyway, lets see if anyone else comes along to comment one way or the other about the gearbox.

[isaldiri]

I know a number of people who have had that issue. All dealt with under the warranty or extended warranty. If you're looking for a potential problem, you can add it to your list.......

[lowndes]

isaldiri said:

Very very few manufacturers don't replace the whole box rather than open it up. FerrariPorsche/Audi etc. everyone just replaces the whole box these days. Mclaren are not alone in doing so...

Porsche gearbox security system . Posted earlier in another thread

[lowndes]

bordseye said:

Anyway, lets see if anyone else comes along to comment one way or the other about the gearbox.

I had no trouble with the geabox in a 650S spider over a year and 4.5k miles; I have a new Super Series due 1 March and have no concerns about the gearbox.

[Thorney]

Might be worth updating this now, we've not seen a bad gearbox for some months, most seem to have been swapped out at someone elses expense. However we have seen a black 12c that keeps coming back into the market with the same gearbox leak, its why we recommend an inspection on any second hand buy, dealer or indy.

[willy wombat]

I don't think that the Porsche "security system" is at all stupid. When I kept my boat on a dry stack at a marina with the bung out, I had handwritten signs all over it saying "bung" to remind me to put it in before launching.