Gearbox oil - Daytonas only

[AllTwelve]

Hi Folks,

I know this has already been discussed on the 'oil recommendation' thread, but this is specifically for the Daytona. Thank you for your understanding and patience!

I want to go RedLine, but I'm having trouble deciding between MTL 70w80 (plus 4 oz. LS additive) or just 75w90 NS.

For the record, we have always used Valvoline Hypoid 75w90, and do not recall ever adding any friction inhibitor. My car has no shutter from the LS, albeit an occasional 'clunk' from a tight turn start.

My issue is the typical cold 2nd gear syndrome. Shifts from 1st to 2nd are typically stiff. Once hot however, upshifts are fine. The problem I am hoping to improve with the Redline is the downshift from 3rd to 2nd which currently is hard to do (even hot) without a grind unless I really slow down the car. I have come to know RedLine gearbox lube to typically make the box buttery smooth (or close to it), and even had this good result when using it in my old Saab 900!

In the 'oil recommendation' thread, I was figuring through advice to go with the MTL 75w90 plus a 4oz. LS additive.

In having trouble finding 75w90, I spoke directly with a tech at RedLine (Dave) who was familiar with the Daytona and vintage Ferraris. First he informed me that there is no MTL 75w90 and only 70w80. He also indicated that the MT and MTL already have a friction inhibitor mixed in. When I mentioned my issue and what I am trying to achieve, he advised that the MT and MTL would be too slippery for the synchros. He went further to say that adding a LS additive would make them even more slick and only increase the grinding issue.

He went on to recommend 75w90 NS (with no LS additive, period) to slow the synchros down so the can line up more quickly. This coincides with the Forza artical on Boxer gerabox oil - "Redline is also offered in an NS version, which has no additive for the limited-slip differential. This additive which inhibits synchro operation - and thus shifting might be smoother without it - but you may get shuttering of the limited slip in slow corners" (Forza, issue 122, December '12)"

So... such is my conundrum! I know that ultimately the real remedy would be to replace the syncros but that is not an option right now. Thanks in advance to all who chime in!

AT

[DWR46]

I cannot argue with any of the statements made by yourself or others in your post. Since you are already having synchronizer problems, I would try the 75/90 NS. If your shifting is better and you encounter no chattering on corners, then declare victory. If you have some chattering, add a tube of Limited-Slip Additive.

[AllTwelve]

Wow, I was hoping more Daytona owners would chime in!

Anyway, thank you DWR46 for your reply. I did find out that that in the past, no LSD additive has ever been added, and I've never noticed any chatter. So, I'm going to go with the RedLine 75w90 NS. I did get a 4 oz. bottle of LSD additive just in case, and will add just an OZ. at a time if any chatter develops. Will be doing this once the weather gets nice and will post the results in the future.

It would be interesting to know what kind of lube Francois and Nereo were putting in the Daytona race cars, and if they were adding any LSD additive.

Ciao!

AT

[DrewA]

I originally had 75 90 gear oil that contained the LS additive on a recently rebuilt Daytona transaxle. I would occasionally get a grind going first to second.

About a year ago I put in the Redline 75 90 NS. I had the 4 oz bottle of LS in hand but decided to try it without it.

The car shifts perfect, no grind. There is occasionally some shutter when starting off and turning; like truning right or left from a stop light but non if the car is in motion.

I'm happy with the Redline NS. If there was more shutter i would start by adding a oz of a time of the GM LS additive.

Drew