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'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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YOUR RESEARCH'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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Check from there

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Suggestion · Original poster

I'll add the 2.25l and check from there.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Check from there' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check from there' (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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Fill hole

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Suggestion · Original poster

I see in the 101 projects it says to fill to 11mm below the fill hole, but online videos (youtube) say nothing wrong with filling until overflow.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole as best i could

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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.

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Suggestion

Drained and refilled with the correct fluid (also important) 11mm or so from the top of the fill hole as best I could.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole in the right place

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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.

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Suggestion

Interestingly the 6 speed is filled to overflow so I suspect they put the fill hole in the right place.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole too high

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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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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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Suggestion · Original poster

Did the engineers make the fill hole too high?

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed actions (10)

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Check from there

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Suggestion · Original poster

I'll add the 2.25l and check from there.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole

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Suggestion · Original poster

I see in the 101 projects it says to fill to 11mm below the fill hole, but online videos (youtube) say nothing wrong with filling until overflow.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole as best i could

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
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Discussions
Read evidence and context
Discussions that contain suggestions
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.

Suggestion

Drained and refilled with the correct fluid (also important) 11mm or so from the top of the fill hole as best I could.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole in the right place

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
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.

Suggestion

Interestingly the 6 speed is filled to overflow so I suspect they put the fill hole in the right place.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill hole too high

No successful repair reported for this finding.

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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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Suggestion · Original poster

Did the engineers make the fill hole too high?

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill plug

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Suggestion

When I pulled the side fill plug to vent, oil just shot out like it was running from a faucet.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill spec exists

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Suggestion

The fill spec exists for a very good reason.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Fill until overflow

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Suggestion · Original poster

I see in the 101 projects it says to fill to 11mm below the fill hole, but online videos (youtube) say nothing wrong with filling until overflow.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Replace trans oil in my '99 base model 5 speed

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Suggestion · Original poster

I'm planning on changing the trans oil in my '99 base model 5 speed.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run from a faucet

No successful repair reported for this finding.

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Suggestion

When I pulled the side fill plug to vent, oil just shot out like it was running from a faucet.

'99 5 speed trans oil change, why not fill to overflow? why -11mm?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Coverage and how to read this overview

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.

10 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 986Forum: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

1 acknowledgements have no verified action link; they do not establish a repair result.

Outcome without a verified action link

Shockingly, the gearbox was back to normal immediately and has been just fine for the last 4 years.

No unique explicit quoted action; no causal link assigned

Generation: 20261026T112012Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I'm planning on changing the trans oil in my '99 base model 5 speed. I bought 3 liters of the 'special sauce' at my local Porsche dealer. I see in the 101 projects it says to fill to 11mm below the fill hole, but online videos (youtube) say nothing wrong with filling until overflow. Is there any problem with simply filling until overflow? Did the engineers make the fill hole too high? or is it completely fine to fill until overflow?

POST 2Original post

I’ve filled my three Boxsters, my 911’s, and every other manual-transmission I’ve ever had, for 50 years, to the point of overflow, and I’ve never had a problem from overfilling. No oil leaks at the input shaft or output shaft(s) , shift shaft etc. ever. I’ve seen gearboxes that died painful deaths from too little oil. The extra 11mm oil level will make very little difference as the oil is sloshed by car movement, stirred by gear movement, etc. I’m mystified why Porsche makes that suggestion. 11mm? Not 10, not 12mm?

POST 3Original post

Quotes source post: 648123

Yes, filling it until it overflows will most likely allow gear oil to leak out the front input shaft bearing of the trans where it will destroy the clutch. The fill spec exists for a very good reason.

POST 4Original post

Quotes source post: 648124

Well, they are the engineers and that's what they determine to be correct so why put in more then what is specified? Would you fill you engine with oil till it came out the fill cap or just go by what is specified?

POST 5Original post

2.25 quarts is what you need. Don't fill it until it drips. very real risk of getting fluid all over your clutch

POST 6Original post

Input shaft has an oil seal so overfill won’t immediately cause leakage and wet clutch…. But regardless it is specified for reason, and I trust Porsche engineers know how fluid sloshes around when the car is in motion… not logical reason to fill to the plug hole. Because the 5-spd tranny is from Audi, the hole location was not originally designed for Boxster installation thus the height spec., I guess…. It’s not a big deal to check it, if you can bend and mark a paper clip. Can be done faster than typing up a question here.

POST 7 / ORIGINAL POSTEROriginal post

Quotes source post: 648133

Ok, this is exactly why I asked. The hole position was not originally placed for this exact set up. I will DEFINTELY do the -11mm from the hole. I'll add the 2.25l and check from there. Thank you everyone for your inputs :0)

POST 8Original post

Interestingly the 6 speed is filled to overflow so I suspect they put the fill hole in the right place.

POST 9Original post

Quotes source post: 648143

Right, Audi did not design it obviously…

POST 10Original post

To see is to believe! My 2001 was sold with a "bad" gearbox. It was extremely difficult, almost impossible to shift, but the price was so good that I planned on finding a second hand gearbox and swapping it out. I did the usual checks with cables, linkages, and adjustments and everything was OK. I was stumped and already planned on a replacement so I decided that what the heck, I'll do a fluid change. When I pulled the side fill plug to vent, oil just shot out like it was running from a faucet. Clearly somehow the level was much higher than 11mm below the fill plug. Not sure how it happened but luckily no leaking into the clutch or anywhere else. Drained and refilled with the correct fluid (also important) 11mm or so from the top of the fill hole as best I could. Shockingly, the gearbox was back to normal immediately and has been just fine for the last 4 years. Well, that was a long speech. Sorry lol. I would say, and especially with German cars, to follow the factory recommendations. For all the other British, Japanese, and American cars I have owner I never cared or worried about those kinds of things at all.

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