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993 C2 manual gearbox oil type

cryddaboy66

Member
Joined
4 Sep 2013
Messages
14
Having done a search I can't seem to find the answer to my query further below.

The owner's manual states the following for a manual box:

"SAE 75 W 90 gear oil, API classification GL 5 (or Mil-L 2105 B)."

This is what my specialist tells me is in the car, but I am experiencing a slight 'crunch' on gearshifts, which is both worrying and less than satisfying. It would also seem to have nothing whatsoever to do with wear on synchros, as the car only has 26k miles on it (!). The problem is present both cold and hot. Sometimes I manage to get a perfect shift, but more often than not... not.

I've read on a US forum that many 993 owners there swear by Red Line 75W90 NS (apparently the NS stands for 'Non-Slip') and that it is the ideally suited to the 993 manual box and will resolve my problem. I'm thinking of buying some to try it out.

Can anyone make any recommendations? Anyone tried the Red Line oil?
 
Try bleeding the clutch hydraulics as well mine is super smooth on Mobil after 160k miles (it has been changed btw.)
 
:welcome:
And another Speed Yellow 993? We need more pics... :cloud9:
 
Chris993C2 said:
:welcome:
And another Speed Yellow 993? We need more pics... :cloud9:

Glad to 'meet' another Speed Yellow! Impeccable taste....

I'm actually a Brit located in Spain, here are some pics of me and the car en route to new home in Madrid (that's if I can work out how to put pics into a post...).
 

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... but back to the point in question: I am told that precise oil type is key to getting the best from a manual box. Any particular brands or oil that have given A1 results?
 
+1 for checking your clutch is operating properly. Not sure if it is the same stuff but I use Redline Heavy Shockproof oil in my gearbox (C4S) - rated as a 75W90 but its chemistry reduces thinning at gear tooth contact points where it can be classed as a 75W250, apparently. No issues at all.
 
Lovely car, you are very lucky.

Clutch fluid change is a great start, just like the brakes they need fresh dry fluid every few years. If the problem persists I would be looking at your rear engine mounts they have a sell by date.. start to sag then that ruins the shifting, especially from first to second.
As you quite rightly say the gears and gear box should be fine, it's the perishable/soft bits I would be looking at initially.



:?:
 
Off topic but another Brit in Spain with a 993 :thumb: if you find yourself down on the coast near Denia drop me a PM and we can meet up.

ATB :)
 
Love the speed yellow! welcome to the forum

I had my gearbox oil replaced a few months ago, the specialist used Mobilube 1 SHC 75W-90 - I didn't have any problems with gear changes prior to that, but as I had no idea how long the oil had been in there thought it would be a good idea to replace.

They said the oil that came out was pretty gross in both colour and aroma - I'm sure the gearbox feels smoother since the oil change, but I could be imagining that ..
 
MilSub said:
Love the speed yellow! welcome to the forum

I had my gearbox oil replaced a few months ago, the specialist used Mobilube 1 SHC 75W-90 - I didn't have any problems with gear changes prior to that, but as I had no idea how long the oil had been in there thought it would be a good idea to replace.

They said the oil that came out was pretty gross in both colour and aroma - I'm sure the gearbox feels smoother since the oil change, but I could be imagining that ..

Many thanks for the welcome and the info. I am going to change the oil to the Red Line 75W90NS stuff which seems to be popular in the USA and has solved at least one guy's problem (gear crunch) which is the same as me. As the SAE rating is that recommended in the Owner's Manual, I reckon I can't go far wrong.
 
Lovely car, please report back with your findings.

Has your gearbox oil been changed in the past?, could be original stuff?.

Trev
 
Cameltoe & Heel said:
Lovely car, please report back with your findings.

Has your gearbox oil been changed in the past?, could be original stuff?.

Trev

Thanks. Oil has been changed recently (which might be the problem...). I am unsure exactly what type was used - hence getting it changed for the Red Line stuff which is recommended by our American friends. Once the Red Line 75W90NS is in the box I will report back with findings...
 
I changed my oil last year and just asked my local OPC for the recommendation. Took a while, but they came back with 99991754600 and the attached tech note for this recommendation. I also did the rear engine mounts at same time. Maybe the oil is just Mobil rebranded of course :)

My car did have a bit of stiffness going into 2nd when cold when I got it, but this has gone away. Don't really know if that is down to this maintenance/oil change or just me using the car more than the previous owner.
 

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I used the shell transaxle oil as listed in the table above with a good improvement. Got some left if anyone's interested?
 
mightyvr6 said:
I used the shell transaxle oil as listed in the table above with a good improvement. Got some left if anyone's interested?

Yes please. My cars going in next month for a few bits including gearbox oil change. Could you please PM me details on how much you have, cost etc.

C.
 

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