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YOUR RESEARCHDumb gearbox oil question
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Use liquimoly in my 996
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I remembered I used LiquiMoly in my 996 with manual gearbox (75w90) which was recommended and on checking the bottle its GL5 oil.
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I've used Redline before in various cars and tbh despite the claims its never really made a real difference for me.
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Suggestion · Original poster
I remembered I used LiquiMoly in my 996 with manual gearbox (75w90) which was recommended and on checking the bottle its GL5 oil.
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Suggestion
I�m sure you can check HPL, redline or others for a gl4.
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Sorry for *another* oil question...
So I bought another car with a manual gearbox and I'm going through the whole 'which gear oil to put in it' and reading about GL4 vs GL5. That I should avoid GL5 on cars with brass synchronizer rings as it wears them too fast.
I remembered I used LiquiMoly in my 996 with manual gearbox (75w90) which was recommended and on checking the bottle its GL5 oil.
My 996 has had it in since 2017, so far no problems. Synchro's work great etc.
So should I remove this oil from my 996 or keep using it? I tried reading about this online but its highly confusing, there are so many opinions on the matter.
Anyone else running LiquiMoly 75w/90 GL5 in their 996? is it ok to keep using it?
Thanks!
I've been going down the same rabbit hole on GL5 gearbox (looking at Redline 75w-90NS. I wrote to Redline asking the same question and got the following response
Liqui moly works really well, my gearbox was a notchy mess till i added it. Especially good when cold, as with the previous oil I could barely change into 2nd until warm.
I've used Redline before in various cars and tbh despite the claims its never really made a real difference for me. Made my WRX worse somehow...
Stick with the Liqui moly
I just ordered 3 qts of Mobilube ptx from Suncoast Porsche parts online (approx $36 per qt iirc). Sunset Porsche had it cheaper on their site, but emailed me today that the price online was incorrect and really $44 or so per qt.
My local Porsche dealer carried a BG 75wXX gl4 (might be this product, but not certain. Note it�s not 75w90).
I�m sure you can check HPL, redline or others for a gl4. My transmission was rebuilt several years ago by a Porsche dealer and so I am sticking to Mobilube PTX.
A place called gbox in Colorado rebuilds these transmissions and their FAQ says they only recommend porsche transaxle oil.
After doing some more digging I found a couple of gear oils that are compatible with brass synchro's on manuals. Pennzoil and Valvoline syncromesh. The Valvoline claims GL4 but the Pennzoil does not. Both seem to be dino oil but state they are safe for brass syncromesh transmissions.
I bought the Pennzoil for my other car (not 996) but I think I'll put the Valvoline in on my next 996 gear oil change.
Incidentally I think from what I understand about GL5 oils not approved for brass syncromesh's is that the 'wear' or damage that could happen is dependent on how hard you drive the car, if you rev match very well then the syncros aren't working hard and there is less chance of syncro issues with a GL5 oil
The liqui moly is a GL5 gear oil not GL4 for brass syncromesh gearboxes. Modern manuals seem to have steel syncromesh rings now (probably to eliminate lead which is in brass)
Well its been listed as suitable on many sites (pelican, fcp etc), dont get too hung up on some of this stuff. Its a good oil that works well. I'll change mine every year and like they say clean oil of any brand is better than old dirty stuff.
Point is the Liqui moly gives the correct viscosities when cold so shifting is easier, about the same as the Porsche fluid.
Interesting points here:
https://rennlist.com/forums/996-turb...houghts-3.html
Also check here:
https://www.fcpeuro.com/blog/the-def...-transmissions
From my workshop manual:
This is a source reference. Confirm exact model applicability in the original material.
