Author Topic: Rear Main seal install fail, twice! Please help!  (Read 7657 times)

Offline Cbolt18

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Rear Main seal install fail, twice! Please help!
« on: 07 October 2025, 17:43 »
Hi All,

I'm a bit stuck. After about 6 months of owning my 7.5 manual pp I noticed the rear mail seal had a slight leak. I was recommended a decent gearbox specialist with good reviews and I managed to get the work done under the 3rd party warranty that came with the car.

The first install was found to be leaking again during an MOT so I took it back and the garage agreed and said they'll re-do it. I just got the car back today and it leaking again, but even worse than before! Actually leaving oil on the drive now.

I've read pretty much everything there is to read on these rear mains, and I'm convinced they're just not installing it well. I'm sure they're not using the special tool despite me telling them about it.

I think they are going to try and get out of doing the repair again as before this repair they said if it leaks again it's got to be something else wrong, and referenced the crank moving.

I've read about crank walk and I'm almost certain I don't have that. The clutch and car drives fine. I know about the pcv valve but fact that the leak is now worse after the install attempt just tells me they're installing it wrong.

Is there anything I'm missing here? Ideally I'd just walk away from this garage but I don't have £1000 to throw at a main dealer and there doesn't seem to be anyone else around Manchester willing to do the work.

I'm really gutted. Does anyone have the part number for the install tool? I'm might have to buy one. And does anyone have a link to the billet upgrade?

Thanks
« Last Edit: 07 October 2025, 18:14 by Cbolt18 »
2019 GTi PP manual

Offline Adam T7

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Re: Rear Main seal install fail, twice! Please help!
« Reply #1 on: 07 October 2025, 18:08 »
Where in Manchester are you?
MY2019 GTI Mk 7.5 Performance. DSG, 5 Door, Rear Camera, Climate Windscreen and Rear Window Factory Tints, Indium Grey.

Offline Cbolt18

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Re: Rear Main seal install fail, twice! Please help!
« Reply #2 on: 07 October 2025, 18:14 »
South Manchester, but everywhere is pretty close.
2019 GTi PP manual

Offline Adam T7

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Re: Rear Main seal install fail, twice! Please help!
« Reply #3 on: 07 October 2025, 18:52 »
South Manchester, but everywhere is pretty close.

I’ve sent a PM
MY2019 GTI Mk 7.5 Performance. DSG, 5 Door, Rear Camera, Climate Windscreen and Rear Window Factory Tints, Indium Grey.

Offline madstaff

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Re: Rear Main seal install fail, twice! Please help!
« Reply #4 on: 07 October 2025, 20:25 »
Its a PTFE seal and they should be installed bone dry, no lubricating the lip seal when assembling.

You install them, leave for a few hours, rotate the engine say 180 degrees and leave for a few more hours.

This let's the seal mould it's shape to the crank.
« Last Edit: 08 October 2025, 13:26 by madstaff »
2017 Clubsport Edition 40 #706.

Urano grey, 3 Door, Manual, Recaros, Brescias, DCC, Nav Pro, Black roof & tints.

Offline Adam T7

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Re: Rear Main seal install fail, twice! Please help!
« Reply #5 on: 07 October 2025, 20:48 »
South Manchester, but everywhere is pretty close.

I’ve sent a PM

Think you need 20 posts to receive a PM?
MY2019 GTI Mk 7.5 Performance. DSG, 5 Door, Rear Camera, Climate Windscreen and Rear Window Factory Tints, Indium Grey.

Offline Cbolt18

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Re: Rear Main seal install fail, twice! Please help!
« Reply #6 on: 08 October 2025, 11:30 »
I've got the PM, thanks. It's ten posts I think.
2019 GTi PP manual

Offline Cbolt18

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Re: Rear Main seal install fail, twice! Please help!
« Reply #7 on: 09 October 2025, 18:02 »
The garage is sourcing an aftermarket seal and has said theyl fit at their cost, which is good. But after reading the forums I'm not sure an aftermarket seal will be much better.

I'm waiting to hear which one they source, but I'm tempted just ask for my money back and go to VW and get them to fit OEM.

Welcome peoples thoughts.
2019 GTi PP manual

Offline Redreels

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Re: Rear Main seal install fail, twice! Please help!
« Reply #8 on: 09 October 2025, 20:11 »
I think the question needs to be put to the garage. Should it fail again…. What then?

Might be nice if you could inspect the seal before and after? Not saying you should watch them do the work but it would be worth a nosey.

Can you download the work instruction from erWin? For the sake of £8.00 would be worth having a copy

Offline Cbolt18

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Re: Rear Main seal install fail, twice! Please help!
« Reply #9 on: 10 October 2025, 09:19 »
They have sourced an Elring rear main seal, does anyone have any experience with these?

https://www.eurocarparts.com/p/elring-crankshaft-seal-369440770?utm_source=google&utm_medium=cpc&utm_campaign=16073774535&utm_content=&utm_term=&gad_source=1&gad_campaignid=16079346400&gbraid=0AAAAAD1aCJiTeMLir20MbITYP9-AUrgJP

I have asked what happens if this doesn't work and although they are saying they really want to get it sorted they're being a bit evasive, suggesting that something else may be wrong.

I fear I don't have much of a choice but to try this new RMS. If that doesn't work then I'll just have to fight my corner.

Unfortunately I've got a two week old baby so can't really spend any more time checking their work. Id stand there and watch them all day if I could.
2019 GTi PP manual