Does This Assumption Work for an ATF Fluid Tranny....?

[Idrinkmotoroil]

High everyone, you may have read some of my earlier posts, this is a bit of an extension of those posts concerning poor shifting of my 5 speed manual transmission.

I have a 2004 Dodge SRT-4 which has a 5 speed manual transmission made by New Venture T-850 with Quaife limited slip ATB differential.

From day one this transmission shifts very poorly, worst shift is 1st to 2nd, lots of crunching feeling slight grinding at times, sometimes it just would not go into gear for several seconds. The stock fluid is 2.5 quarts with Chrysler ATF+4 with 4 oz of Mopar Friction Modifier (about 5% by volume). Why they recommend a friction modifier is beyond me as this is not a clutch style lsd.

I have since switched to Redline C+ATF, the shifting improved a fair bit, hard fast shifts are near perfect, slow lazy shifts are still a bit notchy but not near as bad as with the stock fluid. I first tried it without the Mopar Friction Modifier , then later on added about 2 oz of the FM about 2% by volume, or half the maximum amount of FM. I think the transmission shifts worse with the added friciton modifier but not much I can do about that now, but still overall much better shifting than with the stock setup.

My assumption is this: The C+ATF Redline fluid is reported to have 30% more viscosity than the stock fluid according to Redline. This fluid shifts better than the stock fluid. Would I be wrong in assuming a fluid such as Redline MTF might provide even better shift qualities as it has an even thicker viscosity as the C+ATF. Do you think the added viscosity is the reason for better shifting ?, do synchros work better with thicker fluids ?. Any opinions would greatly help. I asked Dave about the MTF at Redline, he just said it has more viscosity than the C+ATF, no info on how it would perform in my transmission.

thanks in advance for any replies.

Joey

 

[TooManyWheels]

Joey:

I did a little Googling to come up to speed on your situation and was a little surprised by what I found. Over at the TurboDiesel Register there is a discussion by a Pennzoil product VP about your trans using "Synchromesh" Fluid, which does NOT seem to be the same as ATF+4. How does that correspond with what you know?

 

[Idrinkmotoroil]

Toomanywheels, I do appreciate you looking that up for me. I do know that New Venture was formed between GM and Chrysler many years ago and many of their transmissions have used Synchromesh over the years. I've always regarded Synchromesh as a good fluid for MTF, it would be cool if I could use it.

As far as I know there isnt any recommendation to use it on my T-850 5 speed transmission as far as the manufacturer goes, all they state is ATF+4. I would love to try different fluids. Is there any way you can confirm with the guy you found that Synchromesh can work with the New Venture T-850 5 speed manual transmission. There are many variants of New Venture transmissions from T-350, T-1500, T-3000 etc.... , mine is called a T-850 and comes from the factory with a Quaife ATB differential - lsd. Any more info you could obtain would be great, thanks

Joey

 

[MolaKule]

"The C+ATF Redline fluid is reported to have 30% more viscosity than the stock fluid according
to Redline. This fluid shifts better than the stock fluid. Would I be wrong in assuming a fluid such as Redline MTF might provide even better shift qualities as it has an even thicker viscosity as the C+ATF. Do you think the added viscosity is the reason for better shifting ?, do synchros work better with thicker fluids ?. "

The thickest ATF fluids from Redline are the High temp ATF and the Racing ATF. Higher (or lower) viscosity alone doesn't guarantee better shifting. Friction modifiers AND the correct viscosity determine how well a transmission shifts.

The MTL should be tried first as it has the closest viscosity and add pack to Synchromesh.

My recommendation is to try the various Redline Manual Transmission fluids, with various proportions of MTL/MT90.

[ December 19, 2003, 05:32 PM: Message edited by: MolaKule ]

 

[Idrinkmotoroil]

Molakule, so you think I should try the Redline MTL next, perhaps as an experiment, you think it would be compatible with my transmission ?.

One last question, if you put in a different fluid and find that the transmission shifts better, is it safe to assume that you are not damaging the transmission or wearing out the synchros despite the different fluid ?. I would think that you are doing more damage to a transmission when it isnt shifting smoothly , and the synchros are out of sync if you will.

all opinions welecomed. thanks!

JOey

 

[unDummy]

Since its not an automatic, I see no reason why you can't give the MTL a try. MTL is a little thicker than the ATFs and might slow down the shift.

Also, Neo and Honda make MTFs. Neo thinner than the ATFs and might be worth the experiment.
Honda/other OEM fluids are worth a shot if you don't mind the expense of wasted efforts.

If crunching is reduced(or the same) and noise level/temp isn't increased, the fluid is probably not increasing wear.

 

[Idrinkmotoroil]

today I switched to Redline MTL with good results, I will make a new thread discussing performance of my transmission with this new fluid so I can get specifics relating to where I am at with this testing process. thanks to everyone's help.

Joey

 

[o2compressor]

any update?

 

[SteveSRT8]

An interesting issue. We've owned an SRT4 and I have two locals with highly tuned ones that I get seat time in.

I always thought they shifted pretty easy and sweet. Maybe they already discovered Redline!

 

[hooligan24]

I have tried Amsoil ATF, Mopar ATF+4, Redline MTL, and Redline C+ATF in my SRT4. Up here in the PNW, the C+ATF works the best for shifting but I dont know what is going on for wear. The Amsoil didnt seem to keep shifting smooth for longer than 1-2k miles. The MTL was notchy when the temps started to cool down in the fall.

After talking with Dave numerous times, we decided to give a 1qt MTL and 1.6qt C+ATF a try(with no L/S additive) to see what happens. Shifting is nice and smoothe. Dave says C+ATF is more than enough, but adding the EP and AW additives in the MTL wouldnt hurt either.

One of the SRT4 Engineers says the 4ounces of L/S additive was added to the 04/05's because of complaints of the trans shuddering when the steering wheel was at full lock and taking off from a stop.

 

[TurboLuver]

I'm running Amsoil Synchromesh MTF right now and the trans shifts like butter. I got away from ATF's because I am most concerned about wear. I am convinced Dodge started using ATF in manual transmissions as a cost saving measure, not because it was the best fluid.