15 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHWHAT GEARBOX & DIFF OIL ??
Leading reported evidence
Use fuchs titan gear semi synthetic 75w-90
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Suggestion
Got all mine from opie earlier this year, on the engine oil front buy 10 litres as I had hardly any left for the top up bottle out of the 9 litres purchased after filling the motor up.
Leading evidence: 'Use fuchs titan gear semi synthetic 75w-90' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Fill motor up' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Use total's transmission oil in mine at £10 per litre
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Reported fixes
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Performed · outcome unconfirmed
I'm not sure why you are getting 20 litres, just order what you need form Opie oils or similar, 6 litre is the max you need, 75/90 synthetic gear oil GL4/5, I used Total's transmission oil in mine at £10 per litre.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
Got all mine from opie earlier this year, on the engine oil front buy 10 litres as I had hardly any left for the top up bottle out of the 9 litres purchased after filling the motor up.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
Shell Spirax is what I've put in my 986S (changed at 50k) after seeing it recommended on here.
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Fill motor up
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Reported fixes
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Unsuccessful attempts
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Read evidence and context
Discussions that contain suggestions
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Got all mine from opie earlier this year, on the engine oil front buy 10 litres as I had hardly any left for the top up bottle out of the 9 litres purchased after filling the motor up.
Use total's transmission oil in mine at £10 per litre
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I'm not sure why you are getting 20 litres, just order what you need form Opie oils or similar, 6 litre is the max you need, 75/90 synthetic gear oil GL4/5, I used Total's transmission oil in mine at £10 per litre.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T044418Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
First thing am I correct thinking the gearbox , front and rear diff use the same oil ?
Looking for advise on which oil to buy for my gearbox and diff
Been quoted £420 +v.a.t from porsche minimum order of 20 litres (porsche own brand)
Been quoted £220 from euro for 20 litres of mobil ptx 75w90
What are your recommendations ?
Cheers
I've done mine with Mobil SHC 75W-90. It can be bought in 1 liter containers, and IRC you need ~4 for the gearbox and 2 for the diff. Fill up to the fill plug for both.
https://www.renntech.org/topic/5354-front-differential-oil-change/
I'm not sure why you are getting 20 litres, just order what you need form Opie oils or similar, 6 litre is the max you need, 75/90 synthetic gear oil GL4/5, I used Total's transmission oil in mine at £10 per litre.
The rear diff shares the same oil as the manual gearbox. I think it's sparate on a Tiptronic, but don't quote me on that as I have 0 experience with Tips.
Great info, this is something I should do for mine, the gearbox seems fine but is a bit slow when cold and fresh oil is never a bad thing. I might give the Penrite ProGear a try, it's a 75/90 GL5. Looking at all the shifter threads I also note mine has a bit of slop in the mechanism so that will improve things also.
Do I understand correctly that these gearboxes once again have sealed rolling element bearings in them? Oil changes won't help them mush if at all, they basically have a finite lifetime and simply need the box rebuilt from time to time?
Yes, there are two (super expensive) sealed bearings where the pinion and input shafts go into the diff casing, they lose their grease after a while and just rely on gearbox oil getting past the seals to lubricate, the same way the IMSB does, I made sure my gearbox bearings had their seals remove before the box went back together to allow more oil in.
Had a good chat with tim today from OPIE OILS :thumb:
This guy knows his stuff I'm ordering a full stack next week
All fluids in car are being supplied by opie oils
I'll keep you guys updated
We need more knowledge on this subject
This attitude of the gearbox is knackered isn't good
I think people are making an absolute fortune from this !
Got all mine from opie earlier this year, on the engine oil front buy 10 litres as I had hardly any left for the top up bottle out of the 9 litres purchased after filling the motor up.
Might give mine a diff-oil refresh when it goes in for the MOT.
Is it an easy job to do on day, "driveway motors", or just a bit of a mess, so let them deal with it with a ramp?
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