Transmission gear Oil

[MadFiat]

That I'm not too sure about because the sounds of things will be different depending on the car. Some chatter as you start moving is normal from what I can recall.

Also, day 2 with the Royal Purple is much, much better. Definitely a fluid related issue for 90% of what I was experiencing. It's lifetime fluid if you're a street driver but no way is it lifetime for actual racing....nooooo way. 4 years of lapping/autox/drag racing. The shifter will fix the other 10% of issues and then I'll see how the fluid ages and how it behaves in actual cold weather (-30C). A lot of the people on AbarthChat can't think outside of their bubbles and think 32F is really cold and that their "street driving" is the end all of experience .

I'm glad I race, there's no room for BS when you track a car.

Are you using Royal Purple Syncromax or Max Gear? I noticed the Syncromax doesn't have a weight rating listed, and investigated.. it says it's appropriate for manual transmissions that specify automatic gear oil. However I believe the Abarth's fluid needs to be a manual fluid at 75w. I'm not against going a bit out of spec for a better experience, but have read lots of warnings not to use auto fluid/syncromax in transmissions that specify 75w. I would lean toward the Royal Purple Max Gear 75w90 being the safer choice. Am I wrong?

[doverosx]

I'm using Royal Purple Syncromax. It is a GL4 compatible oil and kinematic viscosities suitable for replacing the DD635 CVT oil from Mopar.

One thing on a dead forum, was my explanations behind oil viscosity and what is really important. The SAE stuff is a "category" of viscosity but oil is NEVER a straight weight and so the SAE rating doesn't characterize the oil's viscosity throughout a range of temperatures. For that, you need to look at the kinematic viscosity of the oil at two temperatures; cold (40C) and hot (100C).

Here is why I opted for Royal Purple: http://www.royalpurpleconsumer.com/asse ... atalog.pdf On page 69 Mopar lists C635 DDCT fluid and Synchromax. I looked up the viscosities of Synchromax and considered using Redline 75w-85 which is also a GL4 compatible oil, however, I drive my car in extreme cold and syncromax has a slightly lower pour point and lower cold viscosity.

[MadFiat]

Change my fluid to Royal Purple Max Gear today...

I feel quite stupid. I thought that there was enough gear oil in the trans after reinstalling... checked the drain hole and thought I could feel oil. Apparently I guess it was just "wet" and not actually full like I thought. Turns out it was... quite shockingly low.

So... now it's full of Royal Purple max gear and much quieter and smoother (d'oh) ... if my transmission lives a long time after this fuckup, then I will wholesale vouch that the 2015 transmissions are indeed strong.

[NGEN]

I have to vouch for syncromax by royal purple. It is MUCH better then the mopar. If you need to change your trans fluid, go with royal purple. When I changed the clutch, I put mopar in. It was ok but decided to switch to royal purple. It makes a world of difference.

[MadFiat]

I have to vouch for syncromax by royal purple. It is MUCH better then the mopar. If you need to change your trans fluid, go with royal purple. When I changed the clutch, I put mopar in. It was ok but decided to switch to royal purple. It makes a world of difference.

I used Royal Purple Max Gear because it is closer in spec to the factory fill... but both Royal Purple oils come highly recommended.

[FartieBartie]

I'm glad to see you all are having good results with the Royal Purple, it really does seem to be a better option (and cheaper!) than stock.

I have not experienced any degradation since my change over (2-3k miles ago), so at this point I'll tentatively say I think it is safe for use in our transmissions.

Cheers!
Nate

[doverosx]

Synchromax is closer to viscosity than Max Gear....again, look at the kinematic viscosities. The sae rating doesn't show the full viscosity profile the oil.