purduepurdy

Had an old timer tell me not to use synthetic tranny fluid the other day. It will supposedly increase slippage??? Never heard of this and was thinking of doing a fluid swap sometime. Has anyone ever had problems with synthetic tranny fluid? What brand you running?

soulezoo

Sorry, but that seems to be the silliest (ok-- so not it's not) thing I've heard. Trans fluid is something that is specific to trans and has narrow specs to follow. That's why so many kinds, (mercon, dextron, etc.). I can't see a manufacturer spending all that money into a product for R&D to have something that would increase slippage/decrease performance.

If you want to use synthetic, pick your poison-- redline, royal purple, amsoil, or others and be happy and don't look back.

The first property of the fluid is for lubrication (think transfer case) and synthetics are superior. The biggest reason you will want it is for temperature protection. Read: it withstands heat much better. Some folks report better fuel mileage. Honestly, I didn't see it in mine. But it is still possible. There are other benefits too. Increased "slippage" isn't one of them. Sounds like one of those old myths still circulating to me. Just my .02.

Turbobob

The factory fluid in the 48RE IS synthetic! Valvoline ATF4+ can be bought anywhere, but at my next drain interval, I'm gonna try the Amsoil!

soulezoo

I've got a Goerend going in the truck in the next week or two and it will be fed with amsoil too...

woodrep

I just turned in an order for ALL Amsoil this week. They know what they are doing. Just my .02

D-Roc

I ran Amsoil in mine and it was an improvement over the Mopar ATF 4, but I recently installed Redline C+ATF. I have a g56 in my rig.

purduepurdy

Glad to get ever one's opinion and it's official now, the old man was off his rocker. I used Mobile 1 synthetic(or so they say) tranny fluid in my old cherokee and never had a problem.

CD in NM

My G56 is coming due for a fluid change, Amsoil ATF already in my garage. I plan on doing the change this weekend. I use synthetics in everything I can pour them into.

Sounds like the old fellow is regurgitating old wives-tales when synthetics first became popular and had no real history. Now history should be the guide, they out perform anything dyno, lots and lots of satisfied users. Even the manufacturers use and recommend them. Stone age dyno fluids are just about history in their use and application.

CD

Roperteacher

Just as CD said, I switched all my fluids ( Except Oil) over to AMSOIL when my truck had less than 500 miles on it. G-56 and Rear diff. I even replaced the power steering fluid with AMSOIL ATF. It made a world of difference on my 06 and my 07 really likes it too!

DBLR

Used Amsoil ATF in mine at 10K and now the trans seemed to shift a lot better and it surprised me that 6.5qt of ATF would make a big difference in how it shifts.

topless

He's not crazy, when synthetics first came out, not all of the clutch materials were compatible and they did slip, especially in the new "overdrive" transmissions. The worst problems were with Mopars.

D-Roc

Also check out Redline C+ATF- gave me some positive benefits over the Amsoil ATF I was running in my G56

soulezoo

There is some merit to what you say, not simply to the issue of this thread but for any issue. Some opinion of something that may have been half true from 20 years ago gets stuck into a persons head and it is fact from there on out regardless of how time may have changed things. And you jsut can't seem to change their mind regardless of the facts put beofre them.

Kurt Smith

Question: So was the OEM Mopar ATF+4 in my G56 non-synth/dino oil?

I only have 1k miles on my g56 but I got into a situation (see other thread) where I got my clutch extremely hot. The smell is still in the truck. After doing this I know it is probably my imagination but the synchro's seem to not work as well.

Anyway I thinki I will go tomorrow with a change to Redline C+ ATF in the G56. Have had Redline do wonders with balking synchro's in other vehicles.

Neight

Is it true that synthetic tranny fluid will help your tranny run cooler? I have heard this from a few people.

Thanks