Synthetic Oil in engine, transmission and differential

What experience has the list has in using synthetic oil in the '78 308 GTS carb
engine, transmission and differential? On the advise of a Mercedes specialist I put Mobile1 Synthetic ATF in my 240D (manual) transmission. The result was much smoother shifting. I have run this oil in the trans. for two seasons now with excellent results. Is it possible that Mobil1 Synthetic ATF would improve the shifting in my 308 GTS without any adverse effects? I have used Mobile1 Synthetic 15/50 in the Mercedes 300TD engine which dramatically improved the cold weather starting. Unfortunately Mobile1 15/50 is not being supplied anymore in the Pacific Northwest so I will likely have to go to 5/50 in the future or Mobile1 5000 unless you have another recommendation. Jim

 

Do a search and you will see a large variation of opinions. I personally use all synthetics in my 86 mondial3.2 and wont go back. Here is a good read:

http://www.ferrarichat.com/forum/showthread.php?t=59666

 

It seems that I've read quite often that the synthetic transmission fluids are just too slippery (sp?) for the 308 gearbox. Redline 75w90-NS (for "Non-Synthetic") is a commonly used fluid with excellent results. My car currently has Swepco gearbox oil in it, which I believe is available at the dealer. FWIW, I'll be using the Redline stuff at my next change.

Aaron

 

NS doesn't mean non synthetic it is Redlines discription for their "non limited slip" product. All of redline products are synthectic. In some Ferrari gear boxes if you use NS formula you may have to add a small amount friction additive. In my 355 I have used both NS formula and the reg. 70-90w they both work fine. In my 348(which has the worst shifting Ferrari gearbox) I used the NS formula with a little GM limited slip additive(the amount seems to vary by car). In my 308s either one seemed to work ok but, I think I would err on the side of using the NS formula and if needed some additive. I also have used Redlines MTL formula in my 308s too and it worked fine. Redline by far is the best gearbox oil to use, I have tried about everything over the last 30 years in Ferraris and other cars I've owned it always seems to equal the best shifting. Regards, Vern

 

Thank you for the correction! Just goes to show ya' what "assuming" something does....

 

Color me the underdog, have had very good results in the tracked 308QV using Amsoil SVG 70-90 synth. For the record, AM NOT a lame Amsoil head, as i prefer Mobil 1 synth for engine oil. The Amsoil SVG is for 'severe' use and need not any slip additive.

And shifting is like butter... and second gear is good when cold if a small, tiny bit notchy but once the car is a touch warm (5 miles) second gear is also like butter. NOTE: track the car 25+ times a year so weak oils/fluids ARE NOT in my vocabulary.

 

What symptoms should you look for to tell if you need to add any of the friction additive?

 

I had the same question. Do you listen for a grinding/snapping noise from the diff, or what? And, just ballpark, how much would "a little" additive be?