Thread: Recommended Trans Fluid

So i have a feeling that this one may start a dispute, or may not but in peoples opinion which is the best ATF to use? I have a shift kit on so i am going to buy some fluid either today or tom.

I do not believe Dexron VI is a full synthetic. I am a solid believe in full synthetic transmission fluid. It helps reduce temps, lasts longer and provides better protection.


Now, that all said, I had never considered using a thicker fluid (more viscous) until I met Trannyman. I would have never done so out of fear the pump would not do well with it. But Trannyman I believe runs a bit thicker fluid (I will let him give the details if he so chooses) and his reputation speaks for itself. So in my mind, Im thinking, and Trannyman correct me if needed, that a slightly thicker full synthetic may be a good combo.

But again I know fluids, but trannyman knows trannys and he would be the better source of information in this case.

I don't know if the mix Dave (Trannyman) makes includes a synthetic, but there is one part of his blend that is thicker. His explanation in another thread made since and his blend is in my transmission.

If your question is simply if synthetic transmission fluid is better than conventional transmission fluid, then my answer would be yes. They (synthetics) reduce heat, less prone to oxidation and break down, flow better at cooler temperatures, have a longer life, etc. They do cost more, make no mistake but well worth it.

Originally Posted by 19SE92

Transmission are made for a certain weight fluid or oil then if it gets to thick then problems can happen

And in your vast range of experience and knowledge, just what weight would that be?

LOL. Yeah, thats me. When I get my car back together, I'll be adding an external filter for my transmission fluid as well.

I ran Redline D4 for 70K, then switched to Royal Purple Max ATF when I got my built trans because I couldn't find the D4 anywhere

Originally Posted by SyntheticShield

LOL. Yeah, thats me. When I get my car back together, I'll be adding an external filter for my transmission fluid as well.

That's just because of OCD related to lubricants.

Originally Posted by IndeedSS

That's just because of OCD related to lubricants.

I dunno about that. When I was in the military, I saw them doing it all the time and when I asked about it and was fortunate enough to be educated by a person that new a little bit about what was going on and explained it fairly clearly and I was hooked.

The military really did a number on me when it comes to preventative maintenance. If I could replicate the Preventative Maintenance form they used I would probably do so and use it on my vehicles. It was simply just a very well proven way to do things and that stuck with me. Couple that with the oil analysis of the motor oil, transmission fluid and so on, it really offers you the opportunity to be well on top of any issues before they leave you stranded.

I read a report, maybe two years ago about the military used oil analysis system. They first started using it on a limited basis in Europe. I think it involved some 15,000 vehicles and tanks and so forth. Just that limited test was saving them several 10's of millions of dollars in maintenance costs. That doesnt even cover the environmental impact from severely reduced waste such as oil filters.

I was kidding. However, isn't there a point of overkill or going beyond the added benfits, for the application in use? Not saying this is the case, because, I have no idea. Just a devils advocate POV.

wow i had a feeling that this post might get 2 pages of replies, but i think i am going to stick with the regular fluid, i would like synthetic but the cost is kinda high right now( which doesn't bother me) but i have been told that the tranny's on the gtp's are prone to problems around 120xxx, and well i have 153xxx..... so switching to synthetic might be something i hold offf on for right now.Plus if you do an entire flush you may end up with tranny problems because, and this is had to explain, but the little amount of gunk that is in there is so called keeping somethings together( I hope that makes sense in a way), or so i have been told

Originally Posted by IndeedSS

I was kidding. However, isn't there a point of overkill or going beyond the added benfits, for the application in use? Not saying this is the case, because, I have no idea. Just a devils advocate POV.

I dunno, I guess if I spent more on Oil analysis than an engine or transmission is worth, then I suppose. When I can SAFELY run 15, 20, 30k miles on an oil change with no degradation to the engine I think you would be hard pressed to reach a point of overkill. I ran 15k on one oil change with a LIM leak. The engine never showed any significant increase in wear.

Additionally, the oil analysis gives me much more advanced warning of any impending trouble such as coolant leaks LONG before they leave me stranded somewhere.

So from my personal viewpoint and several years of experience using oil analysis, I dont think you could reach a point of overkill anytime soon. Yes, the additional cost is there initially until you establish how far you can go and what the engine is doing. After that point, the cost of maintenance drops significantly.

I sponsor a local drag bike racer who runs in the super gas class, indexes at 9.90 and is trapping around 135 - 140 mph. Its a dedicated drag bike and all it does is go down the track. I took him from spending money for an oil change and filter after every race to just one oil change and one filter in the race season and on top of that reduced his wear numbers significantly.

He runs I believe 8 races a year PLUS his test and tune sessions PLUS his practice sessions. The first season I sponsored him, yes it was an additional cost because we did not know where the numbers would fall. So we were running an analysis after every other race I believe. But we now have him on once a season oil analysis and once a season oil changes. Runs in the neighborhood of $60 for everything compared to around $15 x 8 = $120 and that is conservative because he was using manufacturer filters. So I think a 50% cost savings is pretty significant. And that is just for one bike on his team.

I have pictures (not digital unfortunately) from when he opened up the engine last season (after three years of me sponsoring him) and there was virtually no visible signs of wear in the valve train. When I started sponsoring him he had just rebuilt the engine and was telling me that it was nearly almost a given that you would have to rebuild some part of the engine every season. So factor that into the cost savings as well. He is now getting ready to start his 4th season on that same motor.

We could also add that information is power. Which is better, going down the track and loosing a motor because there was something going wrong internally and was unaware or knowing well in advance and being able to take corrective action prior to race day?

There are just a TON of advantages to using oil analysis. The cost savings is HUGE in the big picture. Just one other quick example. I have a customer that has a commercial floor cleaning business. Its a Dodge 3500 5.9L Turbo diesel. Holds 12 quarts of oil. He was having to change the oil about every 3 - 4 weeks because of the miles he drove. That cost him $40 - 50 depending on where he had it done PER oil change.

He contacts me, we talk. Put him on synthetics, run oil analysis a few times to figure out where he would have to set his maintenance schedule at. He went from oil changes every 5k miles (which as stated he was doing in about a months time) to oil changes once a year or around 60k miles. The oil and the filter ran him around $120 I believe it was because he went with the super high end oil. 40 x 12 = $480 vs $120. Throw in the cost of the oil analysis and I still had him under $250. His wear numbers dropped (less engine wear) and he was getting better fuel economy (less fuel expense). Now he changes the oil and filter once a year, runs an oil analysis to make sure everything is holding up and continues on.

Oh, also, he was using about a quart to a quart and a half of oil between oil changes prior to speaking with me. That has stopped to. He last reported he had to top off with maybe two quarts over the course of a year. Not bad in my opinion.

And I have many such examples such as those I mentioned.

he ya go scroll down to the "The myths of the Deadly Transmission Flush", offered up by Trannyman (Tripleedgeperformance)
4T65E Transmission Info

Thank you for posting that.

Originally Posted by SyntheticShield

I do not believe Dexron VI is a full synthetic. I am a solid believe in full synthetic transmission fluid. It helps reduce temps, lasts longer and provides better protection.


Now, that all said, I had never considered using a thicker fluid (more viscous) until I met Trannyman. I would have never done so out of fear the pump would not do well with it. But Trannyman I believe runs a bit thicker fluid (I will let him give the details if he so chooses) and his reputation speaks for itself. So in my mind, Im thinking, and Trannyman correct me if needed, that a slightly thicker full synthetic may be a good combo.

But again I know fluids, but trannyman knows trannys and he would be the better source of information in this case.

Of the two Dexron VI bottles Ive seen, neither claims to be a full synthetic anywhere that I could find. An while I'm on the topic of Dex VI, I wanted to mention that Wal-Mart has there own DexVI now for >$3 a quart. Bout half the price of the other DexVI's Ive seen.

An before anyone rags on "Supertech" I started using the DexIII stuff after a local recommended it telling me how cheap it was an that he had changed it yearly on three vehicles using SuperTech DexIII all with good experiences. Thats no proof of anything but if the DexIII has treated me an him both well, I see no reason not to believe the VI would be good as well. An at about half the price of the "name brand" stuff its cheap preventative maintenance to change.


As far as your opinion on synthetic tranny fluid, I agree, but only on new rebuilds or new trannys. I'm against switching to synthetic once it has a fair amount of miles on it. Ive read to many peoples accounts of switching an then describing it as being "too slick" for the trans to grab.

Also after reading your post I went an found where Dave talks about his own mix an I would be willing to try that as well. Even if I had to buy 5gallons. But it sounded like he could ship out his special 5 or 6qts of special blend an then we dilute that with DexIII in a 5gallon bucket. I'd even wanna try his mix with diluted with DexVI see if we cant make the perfect fluid

PS. Here is the thread that Dave talks about this fluid a little bit. What Tranny Fluid Should I Run

Originally Posted by stlmo_gtp

wow i had a feeling that this post might get 2 pages of replies, but i think i am going to stick with the regular fluid, i would like synthetic but the cost is kinda high right now( which doesn't bother me) but i have been told that the tranny's on the gtp's are prone to problems around 120xxx, and well i have 153xxx..... so switching to synthetic might be something i hold offf on for right now.Plus if you do an entire flush you may end up with tranny problems because, and this is had to explain, but the little amount of gunk that is in there is so called keeping somethings together( I hope that makes sense in a way), or so i have been told

FWIW, I am running Valvoline Dex VI in my tranny. I bought this at NAPA for ~$3.80 a quart. They advertise it as a full synthetic fluid. I am not up on all my fluid stuff...but this is the best deal I can find. I would consider doing this.

And it works fine in my 180k mile tranny.