What fluid are you running in your T-56 ?
03-19-2011, 02:33 PM
#42
There are many opinions on what fluid to use...ATF, synthetic ATF, Synchromesh, ect. Tremec specs ATF, so I run Mobil 1 Synthetic.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
04-08-2011, 08:18 PM
#43
On The Tree
iTrader: (7)
Join Date: Oct 2009
Location: zearing iowa
Posts: 122
Likes: 0
Received 0 Likes
on
0 Posts
Got my t-56 upgraded to Tick level 2 last fall, while it was being built I called Tremec directly, at that point in time they had just certified the use of mobil 1 atf in the t-56 along with dexron 3, these are the only two fluids certified by Tremec for use in these transmission's
Since birth (2006. T56 Rebuilds 4B.)
04-09-2011, 10:24 AM
#45
TECH Enthusiast
Join Date: Nov 2001
Location: Queens, NYC and sometimes Orlando
Posts: 661
Likes: 0
Received 3 Likes
on
2 Posts
There are many opinions on what fluid to use...ATF, synthetic ATF, Synchromesh, ect. Tremec specs ATF, so I run Mobil 1 Synthetic.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
THIS!!
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
04-09-2011, 11:35 AM
#46
THIS!!
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
Mobil 1 ATF
04-09-2011, 03:37 PM
#47
TECH Enthusiast
Join Date: Nov 2001
Location: Queens, NYC and sometimes Orlando
Posts: 661
Likes: 0
Received 3 Likes
on
2 Posts
Mobil 1 was actually the second synthetic I tried (after Redline)
It pretty much gave me the same results (smooth cold shifting, grinding during flat foot shifts)
That being said, my car was a 98 with the old paper lined blocker rings....
04-10-2011, 09:25 PM
#50
Teching In
Join Date: Jun 2009
Location: Lees Summit Mo
Posts: 46
Likes: 0
Received 0 Likes
on
0 Posts
GM ATF DEX 3 only I used to work for gm at chevy dealer for over 15 years and the reason gm saids to use atf is due to the bearings and their specs, oil is to thick and cause them to overheat. same with anything else other than ATF dex 3. GM uses atf due to tigher end play and better cooling. this is what all the shop manuals tell you. but its your car and your money so put what ever you want in it, just my opinion.
04-10-2011, 09:59 PM
#52
I used to work for gm at chevy dealer for over 15 years and the reason gm saids to use atf is due to the bearings and their specs, oil is to thick and cause them to overheat. same with anything else other than ATF dex 3. GM uses atf due to tigher end play and better cooling. this is what all the shop manuals tell you. but its your car and your money so put what ever you want in it, just my opinion.
The trans is set up for ATF, which is a low-viscosity fluid. Gear oil and synchromesh are very viscous, which makes them more resistant to flow, especially when cold.
With this in mind, the tolerances, endplay, and clearances are all set up for ATF, not a 75W or greater.
05-27-2011, 09:52 AM
#53
Please forgive the ignorance (I'm learning here) -- I presume the clutch fluid resevoir should be filled with a DOT 3 or DOT 4 brake fluid? If you were bleeding with a Mityvac would you suck out the old stuff and just fill with DOT 3/4? Where do you add the Dex III fluid for the tranny?
08-07-2011, 03:17 PM
#54
THIS!!
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
Also, didn't they revise the transmissions slightly in '06, so perhaps the VI is correct?
Is there any concrete evidence that VI does not work properly in a newer T56 (not an LT1 or F-body)? Curious why they specified the VI and not that GM manual trans fluid or Dexron III, etc. (yet, left the III sticker on the transmission)?
I was planning on doing the fluid today, but now I'm not so sure if that's a good idea until I find out 100% that the owner's manual recommendation is incorrect, or what GM put in the transmission (if incompatible).
08-14-2011, 03:14 AM
#56
On The Tree
Join Date: Apr 2011
Location: Houston/ Kingsville,Tx
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
I put some Dex IV Valvoline ATF in my old worn T-56 last year and it shifted so crappy I drained it after a few miles and switched to Pennsoil syncromesh which had such great reviews on here a year ago. I really liked the sycromesh allot better than the regular ATF Dex IV (since you can't get Dex III anymore)
Now I just got a stage 2 built T-56 from Jason in Texas and he as well as everyone on here is now recommending regular ATF again.
I may try to get some amzoil ATF but I am sure I will have to order it online since we don't have any stocking dealers.
Anyway what fluid have you had the best luck with? There are NO wrong answerers here just curious what works for YOU.
Now I just got a stage 2 built T-56 from Jason in Texas and he as well as everyone on here is now recommending regular ATF again.
I may try to get some amzoil ATF but I am sure I will have to order it online since we don't have any stocking dealers.
Anyway what fluid have you had the best luck with? There are NO wrong answerers here just curious what works for YOU.
08-19-2011, 03:17 PM
#57
On The Tree
iTrader: (4)
Join Date: Mar 2004
Location: West Portsmouth, Oh
Posts: 182
Likes: 0
Received 0 Likes
on
0 Posts
I've used the Redline D4 ATf also with no issues, I had to remove the tranny and lost a good bit of fluid while doing so, I just drained the rest out and refilled with the Mobile 1 ATF, I've had a buddy use it in another vehicle with no issues, plus its more available at auto parts stores around here.
08-19-2011, 09:22 PM
#58
Dex VI is fine for a T56 There are many opinions on what fluid to use...ATF, synthetic ATF, Synchromesh, ect. Tremec specs ATF, so I run Mobil 1 Synthetic.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
The critical thing is to NOT USE Dexron VI. The new Dexron VI works great in any GM automatic, but it is not compatible with the blocker rings in the T56. GM changed the name of their brand of Dex III to "Manual trans fluid" to refect this change.
Whoever said you can no longer get Dexron III, incorrect. You can get it anywhere, its either going to say Dex III right on the bottle or it may be called "automatic trans fluid". Either way, as long as it doesn't say Dexron VI, its fine to use in the T56.
THIS!!
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
GM screwed up when they said Dex VI was backwards compatible with Dex III
It is, but only for Auto transmissions, NOT manual transmissions that require automatic transmission fluid
That being said, I've tried many fluids over the years and nothing was better than the original GM Dex III
Synthetic shifted much smoother when cold, but I got gear clash at high RPM shifts
It was just way too slick for the synchros....
Went back to conventional GM Dex III and although it was very notchy when cold, it shifted much smoother at high RPMS (after I slowly brought her up to operating temp of course)
http://cadillacfaq.com/faq/answers/pdf/t56-06.pdf
08-20-2011, 12:02 AM
#59
^^Yeah, it seems that it depends on the year/model (car), as the Dexron III is for the older units and around 2006 they changed something and started using Dexron VI, although still put the Dexron III sticker on the transmission...There is another thread in the CTS-V section that aurora40 (sp?) linked a GM PDF, iirc that confirmed this. Too lazy to search right now 
