Transmission fluid for 98 Viper GTS

[Enthusiast]

I'm a new owner of a '98 Dodge Viper GTS and I want to start her off with fresh fluids. One peculiar one is the manual lists Dexron III for the fluid for the T-56 manual transmission. I'm not sure about her maintenance history as it has 35k miles so it might be original or already replaced with something else but it shifts more smoothly and have experienced no grinding compared to some of the more recent TR-6060s I have driven in Challengers which use ATF+4. From my understanding the Dexron III is discontinued and replaced with Dexron VI which seems to be a mixed bag for versions that used Dexron III. My gut reaction to all of this is using automatic transmission fluid on a manual transmission is odd to begin with and I want to know what I should use. Should I use Synchromesh, Dexron VI, or ATF + 4 when changing out the fluid? I don't intend to drive this car aggressively, I just wanted to be reliable and want to treat her right.

 

[Revving2Redline]

Try to make a good connection with one of the better senior technicians at your Chrysler or Dodge dealership. Get in with somebody who understands and knows these cars and probably for a while prophylactically change all the fluids a couple times very early. Try to stay with the same mechanic and service advisor and everything. That car is old enough now I believe in a lot of States you can get an antique tag for it like you can't hear in Kansas. Sounds like it's going to be a wonderful car and hopefully you'll post some pictures down the road when you get time and get it all spiffed up

 

[slacktide_bitog]

Did you get any service records with the car?

Ask the previous owner and/or the shops that serviced the car what was used, if possible. Perhaps a Viper form or club could help you out with a good recommendation.

And most importantly, do you have any pics?

 

[zrxkawboy]

Here is a list a MTFs (posted by MolaKule) that have the same approximate viscosity as Dex III.

The thread is here: https://bobistheoilguy.com/forums/threads/updated-list-of-dedicated-mtf-fluids.277655/ . The most recently updated list is in the middle of page 2.

 

[Whimsey]

My Ford manual trannys that came with ATF shifted much better using a dedicated MTF fluid. I understand that dedicated MTF fluid contains additives that will help the MT last and shift better than using ATF. I used Royal Purple Synchromax because it was easy to get and reasonable for a synthetic MTF fluid that has the viscosity of ATF, that came in the tranny.

 

[LDM]

I'm a new owner of a '98 Dodge Viper GTS and I want to start her off with fresh fluids. One peculiar one is the manual lists Dexron III for the fluid for the T-56 manual transmission. I'm not sure about her maintenance history as it has 35k miles so it might be original or already replaced with something else but it shifts more smoothly and have experienced no grinding compared to some of the more recent TR-6060s I have driven in Challengers which use ATF+4. From my understanding the Dexron III is discontinued and replaced with Dexron VI which seems to be a mixed bag for versions that used Dexron III. My gut reaction to all of this is using automatic transmission fluid on a manual transmission is odd to begin with and I want to know what I should use. Should I use Synchromesh, Dexron VI, or ATF + 4 when changing out the fluid? I don't intend to drive this car aggressively, I just wanted to be reliable and want to treat her right.

Lots of T56 were speced with Dex II/III. My 94 Z28 has the T56 and it has a label right on it that says to use Dex IIe, which was the last Dex II spec before Dex III. Last time I did a fluid change on it I used MaxLife and that was at least 6-7 years ago. No issues with shifting at all.

 

[Greasymechtech]

Amsoil TorqueDrive

Or, use an MT fluid like RoyalPurple Synchromax, BG SyncroShift...

I don't care for Tremec's recommendations.

 

[MrHorspwer]

From my understanding the Dexron III is discontinued and replaced with Dexron VI which seems to be a mixed bag for versions that used Dexron III.

Except for manual transmissions. In the GM world, manual transmissions ad transfer cases that originally specified Dexron III were re-spec'd to a "new" Manual Transmission and Transfer Case Fluid (p/n 88861800), which is the old Dexron III fluid in a newly named bottle.

Tremec also recently introduced a HP-MTF manual transmission fluid that they're explicitly saying is good for all Tremec transmission 2008 and newer (including the TR-6060) but also implying that it is suitable for earlier transmissions, even really old 3-and4-speed transmissions.

 

[Greasymechtech]

https://www.tremec.com/anexos/Literature/HP-MTF%20Condensed%20Specs%20Product%20Info_19Feb2018.pdf

12cst???? They shove a ~7cst ATF at us for decades and then release a 75w85 GL-4 12cst conventional MT fluid .... that's just funny.

Red Line makes a great 75w85 GL-4 MT fluid. Their MTL is pretty good too. Once can assume that any of the synchromesh fluids can be tossed in, weather dependent, and work fine.

 

[MattPersman]

I am/was a Viper certified tech. The ones I service it all supersedes to ATF+4

 

[eroberts82]

my vote is for maxlife..............I do not drive a "performance" vehicle, but do a bunch of towing and atf filter changes and maxlife seems to be on par if not better than most.