365 Boxer gearboxdifferential oil is GL4 or GL5 required

I know this has been discussed on FerrariChat but I wanted tyo get opinion of JRV and the other experst here, as it is all a bit inconclusive over there.

I recently changed to Mobil 1 SHC 75W90 in my Boxer gearbox. I now see talk about this being corrosive to yellow metal synchros. I have emailed Mobil and they say that:

"Well you would need to look in your owner's manual for the specification if it calls for a GL-4 product the Mobil product should not be used on the other hand if the manual recommends a GL-5 then the Mobil SHC product is a good choice."

I can find no reference to either GL-4 or GL-5 in my handbook or in the workshop manual. In fact they each recommend a different oil - Shell Spirax HD90 in the handbook and AGIP in teh workshop manual.

Can soemone tell me which is required and if Mobil 1 SHC 75W90 is OK in my car. I must say that the gear changes feel smoother since I filled with this.

BTW I am pretty certain that my car has the later 512 gearbox fitted from new, should this make a difference.

Simon

Simon,

gearbox type won't make a difference.

All the gearboxes are supposed to be filled with GL-5 as I originally stated on Fchat before the fun got going.

As to the corrosive effects of certian oils to yellow metal...I've yet to see a piece of yellow metal that was damaged by oil. However I've seen plenty of damaged yellow metal from lack of oil and/or lack of proper warm up before hard use.

I've been servicing several gearboxes for the same clients for 20 yrs without problems using GL-5. Perhaps the problems may occur when guys leave the same oil in gearboxes & diffs for 20 yrs without changing? Sounds more likely.

Thank you JRV (is it John or Jim). I agree with what you say and so do Mobil!! I was finding it very difficult to believe/understand how Mobil would make a 'bad' product and then duck the issue.

Sometimes there are just too many experts. I'm certainly not one at the moment, hope to be in the future but will certainly have no 2c's until I _know_ what I am talking about. There is no substitute for experience. Thank you once again.

Simon in London

Simon,
A couple of items worth mentioning...

I rebuilt my 365BB gearbox last Summer...other than some brass in the bearing cages, the synchros are of steel or iron alloy.

I used Mobil 1 in the gearbox, for a while, prior to the rebuild....Although it did shift smoother, I could "beat" the synchros, if I shifted even slightly quickly....Hmm, likely why I did the rebuild??

Currently, I'm running Royal Purple 75-90W, a GL-5 spec oil...Shifts smooth, with no 2nd gear nonsense. Likely Mobil 1 would be fine now, as well.

As you may be aware, Ferrari revised the quantity of gear oil from 5.75l to 7.75l...

Enjoy your BB,

David

Just to add to the forum, I switched to Redline 75w90NS and am really pleased with the lighter feel of the shifting. It is GL5/6 rated that is safe for yellow metals.
Two cents.
DJ

This thread has turned out like I hope the entire board will. Feedback from actual users and their success stories that allows others to draw conclusions without a lot of confusing speculation and heresay thrown in.

I've noticed and I'm particulary happy that Ferrari-Talk has attracted some very high quality owners and enthusiasts. Going forward we can really have an impact on the fun and pleasure of ownership in a nice win/win situation for all of us.

Thanks to all those sharing!

Regards, JRV

As a postscript to this thread I should say that I contacted Mobil and made a bit of a fuss about them recommending 'Mobil1' SHC 75W-90 when there might be a problem with it reacting with any brass in the gearbox. They said that what I should have used was 'Mobilube' SHC 75W-90 that was availaible in the UK (not sure about elsewhere) and safe with brass components. Anyway to cut a long story short it seems that the supplier that Mobil recommened had, in fact, supplied me with 'Mobilube' and not 'Mobil1'. I never noticed this on the packaging or the invoice before.

This is a bit strange as there was no mention of 'Mobilube' on their web site at the time I was first looking and now there is no mention of 'Mobil1'. It seems they have developed the web site quite a bit too. Perhaps they have rebranded the product and changed it to make it safe with brass.

Details of 'Mobilube' can be found at:

http://www.mobil.com/USA-English/Lubes/PDS/NAUSE2CVLMOMobilubeSHC75W-90_80W-140. asp


I had bookmarked the original Mobil1 page also, which is good otherwise I might be feeling it was all a figment of my imagination:

http://dallnd6.dal.mobil.com/GIS/MobilPDS.nsf/26b7c4b33367a4a086256665004e4266/9 51b10d046e0bafd852567ba0050ec5f?OpenDocument

My gearbox seems to be functioning fine 'Mobilube' in the 600 miles I have covered since using it.

Simon,
I was using Mobil 1 in my 328 gear box, but after about 8 months (8-9k miles) I was starting to get some noise from the limited slip at low speed turns starting out from a stop. I was also having some synchro problems (crunches) so I changed to redline 75w-90 NS and now all is well, no cold 2nd gear either. Just be on the look out, the oil may begin to have problems over time...whatever you have in the gear box...