alamantia

iTrader: (10)

After about 10,000 miles I dumped the fatcory ATF out of my 2002 Z28 and toped it off with 4 quarts of mobile 1 synthetic ATF, the car wouldnt shift smooth, so i dumped the Synthetic a few hundred miles later and put regular convetional ATF in and it shifts smooth again.

I assume that synthetic fluid has a different reaction on the syncros?

I thought the car came with synthetic from the factory, i guess i was wrong.

I was reading this artical and it says the exact opposite from what i thought

"Fully synthetic gear oils are also used in many vehicles, and have a greater resistance to shear breakdown than mineral oils. They can improve the shifting performance of "difficult" gearboxes, where the excessive slipperiness of some mineral oils can impede synchromesh action."

http://en.wikipedia.org/wiki/Gear_oil

Has anyone had similar experiances with poor shifting using synthetic ATF and better shifting with conventional ATF or is my trans just weird?

MrEddie

The regular Dexron III is no longer available (factory fill) - however, Castrol and I think Valvoline make ATF that complies with Dexron III and Mercon requirements. This is what I'm going to use in the future.

dailydriver

My experiences;

Regular old, mineral based Dexron 3 ATF (this IS the f body T56 'factory fill' BTW); decent shifting all around.

Royal Purple SynchroMax; I thought my T56 was going to grenade itself (or at least obliterate ALL of it's synchros/blocker rings) in a few days!!!
It would not go into ANY gear without massive grinding/crunching, EVEN trying to shift gently!!
I dumped that QUICKLY and installed;

Mobil 1 ATF; Best overall shifting whether hot OR cold.
I am told that the GM/Pennzoil Synchromesh fluid (it's either ALL mineral based, or a semi-synthetic, NOT sure??) actually shifts better than this (Mobil 1) in warm weather/climes, but much worse (grinding/'notchiness') when cold and/or in cold climes. Who knows??!

alamantia

iTrader: (10)

Royle Purply Royaly sucks *** huh? Ive heard that before, I wonder if ther eis any truth to that, i thought that oil was supposed to be good

BALLSS

i have had good results with Redline D4

ae13291

iTrader: (8)

syncomesh all the way baby!! my trans went into each gear like butter!! it works soooooo good!! i bought it from pepboys, pennzoil syncromesh. it also cured the 3rd gear grinding. i have also added a magnet to my drain plug after seeing alot of metal in the oil floating around

TARZAN

iTrader: (12)

Good luck here with Syncromesh.


-Will

fireman

Honda Z1 ATF

I've used everything over the last 8yrs and this stuff is the best.

m6speed

iTrader: (11)

i used mobil 1 and it was very smooth shifting, i then changed to penzoil syncromesh(gm stuff) and it shifted even easier.

SladeX

Used Mobil 1, regular off the shelf Dexron III, Shell Dexron III, Amsoil and also Penzoil Dexron VI.

So far Mobil 1 was the long running favorite. regular Dexron III worked, but felt tougher to shift when cold. Amsoil was near identical in feel to Mobil 1 but with Mobil 1 cheaper, it was the better option.

Penzoil Dexron VI, while newer, felt great to shift in cold and heck even feels better when warm. So far I've got about 4k on the VI and still liking it. My transmission is rebuilt with a Stage 1 kit (updated blocker rings, sliders, steel fork, syncros, billet keys etc). Even with the 98 transmission basically untouched saved for fluid, all but the Dexron VI was played around with for a good while and beat on hard to get those opinions.

transAm-98

iTrader: (1)

I've used gm synchromesh, redline MTL Mobil 1 ATF and so far the best I've used is the Redline D4

1sick'98WS6

iTrader: (19)

Another Vote for Honda Z1 ATF, I used Sycromesh in past and like the way it shifts now with Honda ATF. And apparently its supposed to be good for our rubber seals in the T56