gearbox oil

[sue11sam]

Hi guys, I posted in error on the tech section, and got no replies, so lets see if posting in the correct forum section is more successful. What is the current thinking on gearbox oil change intervals, milage or time (we have a garage queen here!!)plus the current fashion in gearbox lube, this is a road car which very occasionally is driven enthusiastically, plus apparently according to the dyno, I have 305bhp,(I know could have knocked me over with a feather!) if that makes any difference to your thoughts on the lube spec. Car is a'96 narrow body with 74k killometres.

Cheers Steve

 

[Mark Elder]

Well, I saw your post in the tech session but did not reply because I don't know much. But in the absence of other replies I'll ramble on anyway! I'm sure I've read somewhere that gearbox oil should be changed at the 48K service. My car had a 48K service at 27K miles just before I bought it and by last summer's service I'd put another 30K miles on it. Plus I had a slight whine from the gear box when in 5th gear and my Indy had (a) suggested it was so slight I should not be worrying about it and (b) the first thing to do if I really wanted to worry about it was to change the gearbox oil. So it was changed. The whine disappeared [] but I now have the well reported "bulky change from 1st to 2nd when cold" symptom (which we can all notice on 993s but is now very noticeable on my car). So I went straight back to my Indy and checked the viscosity he used. He had used a generic EP80/90 which is what he believe Porsche recommend for the viscosity. But it is not (see threads below), so this summer the oil will be changed again....but I'm still to make up my mind with what. You will also be confused when you have read a couple of other threads: http://www.porscheclubgbforum.com/tm.asp?m=362460 http://www.porscheclubgbforum.com/tm.asp?m=418443 Let us know what you choose

 

[sue11sam]

Blimey Mark, thanks for that, I think!! some others are using swepco ? think I will have to do some more digging! will let you know the outcome. I do not have any particular problem, just have not changed it since I have owned the car.

 

[bert gear]

Swepco is recommended by Ruff in their 993

 

[sue11sam]

Thanks Bert, yes I have seen that, and a few others beside, will get back to you if I go down the swepco route

 

[dparslow]

I use Valvoline Synpower 75w/90 fully synthetic gear oil in mine and change it every 4 years regardless of mileage in the 993 as it`s a low usage car. The 968 as it`s the daily driver and high usage gets done every 48k.

 

[sue11sam]

Thanks Dave, something else to consider

 

[Jon Kent]

I changed mine to Miller's motorsport grade and the change is noticeably better. CRX LS 75w90 NT for cars with LSD or CRX 75W90 NT for cars without LSD Recommended from my point of view, but I know many others who use and rave about Swepco. Best Rs, Jon (not on commission.....yet)

 

[sue11sam]

Thanks Jon, its all becoming crystal clear!!

 

[A Ward]

I have also changed to the Millers motorsport grade gearbox oil (make sure you get the correct type as they do a LSD variety also as mentioned in an earlier post) - they are often highly recommended for their engine oils as well due to changes in the formulation of Mobil 1 over the years since it was originally spec'ed for the 993. They have a really helpful tehnical info line should you need any advice about selection, etc... I did loads of research on various Porsche forums before I plumped for the Millers. I have to say that the gearbox oil has been in for 4000 miles now and I have been very pleased - but everyone is different. The shifting issue from 1st to 2nd gear is a known 'quirk' of the 993's when cold and there are countless threads discussing this and gearbox oils. I think that the most important thing to remember is that you are changing it for a good high quality product that is of the original specification grade or better, if you don't get on with it you can always try another at your next change? Have to say that changing it is a fun job - if you are doing it yourself invest in some clear plastic flexible hose to enable you to get it into the gearbox filler point from the rear nearside wheel position - and probably a measuring jug as well.

 

[Pete B]

I changed to Redline Synthetic 75W-90 GL5 from Opie Oils. Baulking gone completely and much faster change through every gear. Needed 4 US quarts. Very long series of threads on Rennlist. In particular to avoid any gearbox oil with molywotsit additives as they tend to slow down the syncro and obstruct the changes. HTH

 

[Lawrie911]

ORIGINAL: Pete B I changed to Redline Synthetic 75W-90 GL5 from Opie Oils. Baulking gone completely and much faster change through every gear. Needed 4 US quarts. Very long series of threads on Rennlist. In particular to avoid any gearbox oil with molywotsit additives as they tend to slow down the syncro and obstruct the changes. HTH

I guess you got the Redline 75W-90 NS (i.e. the non LSD version), though the one suitable for LSDs would still be OK.

 

[Mark Elder]

ORIGINAL: Lawrence

ORIGINAL: Pete B I changed to Redline Synthetic 75W-90 GL5 from Opie Oils. Baulking gone completely and much faster change through every gear. Needed 4 US quarts. Very long series of threads on Rennlist. In particular to avoid any gearbox oil with molywotsit additives as they tend to slow down the syncro and obstruct the changes. HTH

I guess  you got the Redline 75W-90 NS (i.e. the non LSD version), though the one suitable for LSDs would still be OK.

So is the gearbox/LSD integrated (ie pour in the oil and it lubs the gearbox and the LSD) - or do us C4/LSD owning folk have option to put LSD oil in the LSD and non-LSD in the gearbox?