Several ?'s Best after market fluids, ect

[JasonSSG]

So I recently changed and upgraded my 2009 Viper's brakes with StopTech Rotors, SS lines, and Stoptech STR 660 brake fluid. I have roughly 17k miles on it. I track the car 5 to 6 times a year. Im over due for rear diff fluid replacement & trans fluid change. I plan on doing this ASAP as track season is upon us. I've been searching a lot of the forums and have only grown more confused as to what fluids I should use. I understand the OEM recommendations but I track my car and if I can get fluids that out perform the factory one I would prefer that route. I feel it's just preventative maintenance given what the car goes through on the track.

1. What diff fluid has anyone seen hold up the best? I understand there's the friction modifier to add but now Mopar and Castrol have fluid with the modifier already added in now. Some like Royal Purple have added in friction modifier too. But is the Royal Purple friction modifier up to the same specs as the OEM friction modifier? Or maybe the Royal Purple exceeds it? Or if you use the Royal Purple maybe one should add the OEM friction modifier to it too?

2. On the trans fluid I read people using all different types of brands, I just want whatever one will hold up the longest under high temp conditions on the track. Anyone have a recommendation from past experience?

3. If the clutch fluid takes just DOT 4 brake fluid would it be fine to just use the Stoptech 660 brake fluid that Im using now. It's high temp brake fluid which I understand absorbs moisture thus requires more frequent brake bleeding, (which I'm ok with doing), but would that have any ill effect on the clutch?

Thanks in advance for any suggestions. Im just trying to make sure I use the best in my vehicle.

 

[MoparMap]

Opinions will always vary on the fluids, but if you drain and refill anything often enough it can work out in the wash a bit. For my money I'll still with factory fill as much as possible. The engineers designed the parts, so they designed the fluid to go with them and I trust all the work and testing they put into it. The transmission is a bit of an exception in that it wasn't developed in-house though and the fluid has been discontinued. I'm currently seeing if I can get the engineers' recommendation on a "factory" replacement. I know the early cars actually had Dexron in them into the late 90s and for a period you could run Dexron or the Castrol Syntorq, so I think it should be fine running Dexron in them. The new TR6060 in the gen 5 runs some variety of ATF I believe.

 

[AZTVR]

the fluid has been discontinued

Which fluid has been discontinued ?

 

[MoparMap]

The Castrol Syntorq LT transmission fluid. Have called around looking for some as I need to change mine, but found out they don't make it anymore. You can still find some old stock, but I'll have to come up with a new solution eventually. Trying to ask the engineers directly what they would recommend as put a little more faith in their word over others.

 

[Allan]

The Castrol Syntorq LT transmission fluid. Have called around looking for some as I need to change mine, but found out they don't make it anymore. You can still find some old stock, but I'll have to come up with a new solution eventually. Trying to ask the engineers directly what they would recommend as put a little more faith in their word over others.

I just got some from the dealer and changed mine last week.
They don't call it Syntorq.

The number on the bottle matches the number on the trans tag still.
............just like always

I wonder if it is discontinued and my dealer has an abundance of old stock...................

 

[AZTVR]

Which fluid has been discontinued ?

The Castrol Syntorq LT transmission fluid. Have called around looking for some as I need to change mine, but found out they don't make it anymore. You can still find some old stock, but I'll have to come up with a new solution eventually. Trying to ask the engineers directly what they would recommend as put a little more faith in their word over others.

Have you tried the GM part number also? ( Mopar is 4874459 and from GM as 12346190 according to Tom F&L GoR)
However, I'd guess that if you are saying the Mopar version has been discontinued, the GM would be also.

 

[MoparMap]

It has been discontinued from Castrol as I understand it, so both the Mopar and GM versions would likely trickle out eventually. I called standard transmission in Texas who used to see gallon containers of it and was told Castrol no longer makes it. I know I can find some still looking up the Mopar and GM part numbers, which I'll probably still do this time around, but not sure how much longer I'll be able to do that. Guessing there is still a fair amount on shelves as the stuff was only used in a few different cars.

 

[AZTVR]

It has been discontinued from Castrol as I understand it, so both the Mopar and GM versions would likely trickle out eventually.

I just did some searching knowing that the NV4500 trans used Syntorq, and came up with this page, discussing a good substitute. NV4500 Manual Transmission Oil
After reading through it, it appears that they are repackaging Redline MT-85 which specifically says that it is a replacement for the Dodge and GM part numbers.

Trying to ask the engineers directly what they would recommend as put a little more faith in their word over others.

That would be the best answer, for sure.

 

[MoparMap]

Yeah, I had seen that page as well. If nothing else I might actually be able to buy that stuff off the parts store shelf, which is nice in its own regard. May have to look next time I go just for fun.

 

[MoparMap]

For what it's worth, Tremec's recommendation is Mobil 1 Synthetic ATF for all T56s. Haven't heard anything from SRT yet, but they didn't make the transmission, so I'm not sure if they would have any different advice.