Which transmission fluid to use in T-56?
04-04-2017, 12:40 AM
#1
On The Tree
Thread Starter
Which transmission fluid to use in T-56? Hey guys! I am planning to change the transmission fluid on my 2001 Z28 for the first time! I have searched the threads across the internet and it seems nobody can agree on which fluid works best! I know the T-56 works best with GM DEXRON 3 ATF, but it has been discontinued for some time now. If I were to use Dexron 3 ATF, the brand wouldn't matter as long as it has the Dexron 3 rating right? And I read mixed reviews regarding synchromesh. Would running synchromesh be beneficial at all?
04-04-2017, 07:37 AM
#2
No. Syncromesh is not a good substitute for derxron 3. Any standard dex/merc transmission fluid with dexronIII markings on the back is the best for a standard t56
There are many many threads, the best choice is standard dex/merc
There are many many threads, the best choice is standard dex/merc
PITA to find it again, but here is their own words of why Dex III only.
http://www.tremec.com/menu.php?m=110
http://www.tremec.com/menu.php?m=110
Last edited by chrysler kid; 04-08-2017 at 12:31 PM.
04-04-2017, 11:33 AM
#7
TECH Enthusiast
Previous info on this topic and multiple links on earlier threads.
https://ls1tech.com/forums/manual-tr...l#post19566068
If it were me with a stock 2001 M6 with the carbon blocker rings, I'd certainly go with one of the synthetic ATF's that carry much stronger add packages than the regular name brand Dex 3's (Pennz, Mobil, Valvoline, Castrol Trans Max, etc.). Even Tremec says it's ok to use Mobil 1 synthetic ATF in these. In my mind the best choices are M1 ATF, Redline D4 ATF, Amsoil Automatic Torque Drive ATF, Honda ATF DW1, BMW MTF LT2, and even the Royal Purple Synchromax or their RP Max ATF. Of that list I'd probably go with the Amsoil, even though it would cost more for the 4 qts. Then M1 or D4. M1 is probably the cheapest. Some push for the Valvoline Max Life ATF which has a great add pack too. My only problem with that is that it starts off at 5.8-6.0 cSt...though will stay above 5.5-5.6 cSt the whole time. If that were 6.5 cSt I'd probably use it. That's really a Dex VI imo.
These synthetics sheer a LOT less than the regular conventional/semi-syn Dex 3's. I've seen some used oil analysis that show the plain old Dex 3's shearing down from 7.5 cSt to 5.8 cSt in only 8K miles. As long as you change more frequently, no problem. The synthetics above will probably hold above 6.4 cSt for 10K miles or more.
Yeah, you could get away with the Pennzoil Synchromesh. It's an even higher viscosity at 9.3 cSt with an add package that puts the synthetic ATF's to shame....it's really a solid GL-4 gear lube. Some of those synthetic ATF's claim GL-4 status but I'm not convinced. The higher viscosities will make your shifting more notchy when warming up in cold weather.
Since my car has the paper lined blocker rings ('98-'00) I prefer the non-synthetic, GM manual trans fluid ATF 88861800. Before that I ran regular Valvoline conventional for 4K miles which shifted just fine...and no different than the factory fill. Can't tell any difference from Valvoline to the GM stuff. The GM 88861800 has a slightly better add package than the base conventional ATF's (more phos and boron), but not that much better. And it falls well short of the add packs in the synthetic ATFs. I change it within 4K miles because I know it will shear rapidly. The better add packs do more to protect your gears and bearings from wear. You want the ideal viscosity + add package for easy operation of your synchros. That's why I would stay in the 6.5-7.7 cSt range, staying with an ATF. Since the licensing for Dex 3 is gone, you can't be 100% sure just what you're getting in anyone's bottle labeled "meets Dex 3 specifications." It's an opinion. So for me, at least GM built my car and they say their product meets original specs.
You really can't go wrong with a name brand Dex 3 conventional or synthetic. Just realize some of them will shear down quickly. Fwiw, that Mobil ATF D/M showed above has a pretty decent add package...probably better than the GM 88861800. I researched actual VOA's and UOA's on these over the past few years. Of the conventionals the Mobil ATF D/M and Pennzoil seemed to be among the best by add packages. Most people don't own their cars long enough, using the same fluids, to really determine what worked best and what didn't.
https://ls1tech.com/forums/manual-tr...l#post19566068
If it were me with a stock 2001 M6 with the carbon blocker rings, I'd certainly go with one of the synthetic ATF's that carry much stronger add packages than the regular name brand Dex 3's (Pennz, Mobil, Valvoline, Castrol Trans Max, etc.). Even Tremec says it's ok to use Mobil 1 synthetic ATF in these. In my mind the best choices are M1 ATF, Redline D4 ATF, Amsoil Automatic Torque Drive ATF, Honda ATF DW1, BMW MTF LT2, and even the Royal Purple Synchromax or their RP Max ATF. Of that list I'd probably go with the Amsoil, even though it would cost more for the 4 qts. Then M1 or D4. M1 is probably the cheapest. Some push for the Valvoline Max Life ATF which has a great add pack too. My only problem with that is that it starts off at 5.8-6.0 cSt...though will stay above 5.5-5.6 cSt the whole time. If that were 6.5 cSt I'd probably use it. That's really a Dex VI imo.
These synthetics sheer a LOT less than the regular conventional/semi-syn Dex 3's. I've seen some used oil analysis that show the plain old Dex 3's shearing down from 7.5 cSt to 5.8 cSt in only 8K miles. As long as you change more frequently, no problem. The synthetics above will probably hold above 6.4 cSt for 10K miles or more.
Yeah, you could get away with the Pennzoil Synchromesh. It's an even higher viscosity at 9.3 cSt with an add package that puts the synthetic ATF's to shame....it's really a solid GL-4 gear lube. Some of those synthetic ATF's claim GL-4 status but I'm not convinced. The higher viscosities will make your shifting more notchy when warming up in cold weather.
Since my car has the paper lined blocker rings ('98-'00) I prefer the non-synthetic, GM manual trans fluid ATF 88861800. Before that I ran regular Valvoline conventional for 4K miles which shifted just fine...and no different than the factory fill. Can't tell any difference from Valvoline to the GM stuff. The GM 88861800 has a slightly better add package than the base conventional ATF's (more phos and boron), but not that much better. And it falls well short of the add packs in the synthetic ATFs. I change it within 4K miles because I know it will shear rapidly. The better add packs do more to protect your gears and bearings from wear. You want the ideal viscosity + add package for easy operation of your synchros. That's why I would stay in the 6.5-7.7 cSt range, staying with an ATF. Since the licensing for Dex 3 is gone, you can't be 100% sure just what you're getting in anyone's bottle labeled "meets Dex 3 specifications." It's an opinion. So for me, at least GM built my car and they say their product meets original specs.
You really can't go wrong with a name brand Dex 3 conventional or synthetic. Just realize some of them will shear down quickly. Fwiw, that Mobil ATF D/M showed above has a pretty decent add package...probably better than the GM 88861800. I researched actual VOA's and UOA's on these over the past few years. Of the conventionals the Mobil ATF D/M and Pennzoil seemed to be among the best by add packages. Most people don't own their cars long enough, using the same fluids, to really determine what worked best and what didn't.
Last edited by Firebrian; 04-04-2017 at 01:31 PM.
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04-04-2017, 12:20 PM
#9
TECH Enthusiast
It's probably also true that Tremec has never taken the time to test any other fluids except conventional Dex 3's, and M1 ATF in the T56's. At least, they don't report that they have done so and achieved negative results. There's a large % of T56 owners using something other than Dex 3. And it's not like the transmissions were failing left and right.
The Forum survey done in 2005 of over 600 responders, 26% were using GM synchromesh. 9% Redline D4, 30% RP Synchromax. 35% OEM Dex 3. That's 65% not using conventional Dex 3's. Results today might be somewhat different as M1 ATF has certainly become a popular choice. The only thing I'm leery of is using some synthetics in the '98-'00 stock T56's.
The Forum survey done in 2005 of over 600 responders, 26% were using GM synchromesh. 9% Redline D4, 30% RP Synchromax. 35% OEM Dex 3. That's 65% not using conventional Dex 3's. Results today might be somewhat different as M1 ATF has certainly become a popular choice. The only thing I'm leery of is using some synthetics in the '98-'00 stock T56's.
Last edited by Firebrian; 04-04-2017 at 01:00 PM.
04-04-2017, 11:05 PM
#10
I am using Pennzoil Dexron III ATF (not their Synchromesh) and it works great. I used to use Mobil 1 synthetic ATF which also worked great.
I heard mixed reviews about Valvoline Dexron III (really popular) so i decided to try Pennzoil instead and i like it.
I heard mixed reviews about Valvoline Dexron III (really popular) so i decided to try Pennzoil instead and i like it.
04-04-2017, 11:57 PM
#11
On The Tree
Thread Starter
Previous info on this topic and multiple links on earlier threads.
https://ls1tech.com/forums/manual-tr...l#post19566068
If it were me with a stock 2001 M6 with the carbon blocker rings, I'd certainly go with one of the synthetic ATF's that carry much stronger add packages than the regular name brand Dex 3's (Pennz, Mobil, Valvoline, Castrol Trans Max, etc.). Even Tremec says it's ok to use Mobil 1 synthetic ATF in these. In my mind the best choices are M1 ATF, Redline D4 ATF, Amsoil Automatic Torque Drive ATF, Honda ATF DW1, BMW MTF LT2, and even the Royal Purple Synchromax or their RP Max ATF. Of that list I'd probably go with the Amsoil, even though it would cost more for the 4 qts. Then M1 or D4. M1 is probably the cheapest. Some push for the Valvoline Max Life ATF which has a great add pack too. My only problem with that is that it starts off at 5.8-6.0 cSt...though will stay above 5.5-5.6 cSt the whole time. If that were 6.5 cSt I'd probably use it. That's really a Dex VI imo.
These synthetics sheer a LOT less than the regular conventional/semi-syn Dex 3's. I've seen some used oil analysis that show the plain old Dex 3's shearing down from 7.5 cSt to 5.8 cSt in only 8K miles. As long as you change more frequently, no problem. The synthetics above will probably hold above 6.4 cSt for 10K miles or more.
Yeah, you could get away with the Pennzoil Synchromesh. It's an even higher viscosity at 9.3 cSt with an add package that puts the synthetic ATF's to shame....it's really a solid GL-4 gear lube. Some of those synthetic ATF's claim GL-4 status but I'm not convinced. The higher viscosities will make your shifting more notchy when warming up in cold weather.
Since my car has the paper lined blocker rings ('98-'00) I prefer the non-synthetic, GM manual trans fluid ATF 88861800. Before that I ran regular Valvoline conventional for 4K miles which shifted just fine...and no different than the factory fill. Can't tell any difference from Valvoline to the GM stuff. The GM 88861800 has a slightly better add package than the base conventional ATF's (more phos and boron), but not that much better. And it falls well short of the add packs in the synthetic ATFs. I change it within 4K miles because I know it will shear rapidly. The better add packs do more to protect your gears and bearings from wear. You want the ideal viscosity + add package for easy operation of your synchros. That's why I would stay in the 6.5-7.7 cSt range, staying with an ATF. Since the licensing for Dex 3 is gone, you can't be 100% sure just what you're getting in anyone's bottle labeled "meets Dex 3 specifications." It's an opinion. So for me, at least GM built my car and they say their product meets original specs.
You really can't go wrong with a name brand Dex 3 conventional or synthetic. Just realize some of them will shear down quickly. Fwiw, that Mobil ATF D/M showed above has a pretty decent add package...probably better than the GM 88861800. I researched actual VOA's and UOA's on these over the past few years. Of the conventionals the Mobil ATF D/M and Pennzoil seemed to be among the best by add packages. Most people don't own their cars long enough, using the same fluids, to really determine what worked best and what didn't.
https://ls1tech.com/forums/manual-tr...l#post19566068
If it were me with a stock 2001 M6 with the carbon blocker rings, I'd certainly go with one of the synthetic ATF's that carry much stronger add packages than the regular name brand Dex 3's (Pennz, Mobil, Valvoline, Castrol Trans Max, etc.). Even Tremec says it's ok to use Mobil 1 synthetic ATF in these. In my mind the best choices are M1 ATF, Redline D4 ATF, Amsoil Automatic Torque Drive ATF, Honda ATF DW1, BMW MTF LT2, and even the Royal Purple Synchromax or their RP Max ATF. Of that list I'd probably go with the Amsoil, even though it would cost more for the 4 qts. Then M1 or D4. M1 is probably the cheapest. Some push for the Valvoline Max Life ATF which has a great add pack too. My only problem with that is that it starts off at 5.8-6.0 cSt...though will stay above 5.5-5.6 cSt the whole time. If that were 6.5 cSt I'd probably use it. That's really a Dex VI imo.
These synthetics sheer a LOT less than the regular conventional/semi-syn Dex 3's. I've seen some used oil analysis that show the plain old Dex 3's shearing down from 7.5 cSt to 5.8 cSt in only 8K miles. As long as you change more frequently, no problem. The synthetics above will probably hold above 6.4 cSt for 10K miles or more.
Yeah, you could get away with the Pennzoil Synchromesh. It's an even higher viscosity at 9.3 cSt with an add package that puts the synthetic ATF's to shame....it's really a solid GL-4 gear lube. Some of those synthetic ATF's claim GL-4 status but I'm not convinced. The higher viscosities will make your shifting more notchy when warming up in cold weather.
Since my car has the paper lined blocker rings ('98-'00) I prefer the non-synthetic, GM manual trans fluid ATF 88861800. Before that I ran regular Valvoline conventional for 4K miles which shifted just fine...and no different than the factory fill. Can't tell any difference from Valvoline to the GM stuff. The GM 88861800 has a slightly better add package than the base conventional ATF's (more phos and boron), but not that much better. And it falls well short of the add packs in the synthetic ATFs. I change it within 4K miles because I know it will shear rapidly. The better add packs do more to protect your gears and bearings from wear. You want the ideal viscosity + add package for easy operation of your synchros. That's why I would stay in the 6.5-7.7 cSt range, staying with an ATF. Since the licensing for Dex 3 is gone, you can't be 100% sure just what you're getting in anyone's bottle labeled "meets Dex 3 specifications." It's an opinion. So for me, at least GM built my car and they say their product meets original specs.
You really can't go wrong with a name brand Dex 3 conventional or synthetic. Just realize some of them will shear down quickly. Fwiw, that Mobil ATF D/M showed above has a pretty decent add package...probably better than the GM 88861800. I researched actual VOA's and UOA's on these over the past few years. Of the conventionals the Mobil ATF D/M and Pennzoil seemed to be among the best by add packages. Most people don't own their cars long enough, using the same fluids, to really determine what worked best and what didn't.
04-06-2017, 12:43 AM
#13
hard to really say though as you can never be sure how many year 2000 T56's they had at the end of the run to be sure that version of the transmission isnt in a 2001 car.
same with the rod bolts. people say 2000-2002 LS1's had "better" rod bolts than the 97-99 LS1. if i have a year 2000 car, surely the year 99 engine run didn't end exactly with a 99 car and vise versa - they could have had a shortage of engines and a year 2000 engine made it into a 99 car.
04-06-2017, 10:48 AM
#14
TECH Enthusiast
Good point by Bigsticksupra. You can never say never. But the vast majority of 2001 and up Tremecs should have come with carbon blockers. And if your transmission was ever rebuilt, odds would be even higher they have carbon blockers.
The fluid you end of using should be based on how you use your car. For moderate street use only the ATF's should be more than fine. For someone who is really going to flog that transmission by hard tracking/racing the car consistently, then maybe a stronger Manual Transmission Lube like the Synchromeshes are needed. Then again, there's the example of Sam Strano who Auto-crossed his 2001 Z28 T56 to SCCA-solo national titles supposedly on the stock synchronizers using synthetic ATF...and pushing to 150K-175K miles on the original transmission.
The fluid you end of using should be based on how you use your car. For moderate street use only the ATF's should be more than fine. For someone who is really going to flog that transmission by hard tracking/racing the car consistently, then maybe a stronger Manual Transmission Lube like the Synchromeshes are needed. Then again, there's the example of Sam Strano who Auto-crossed his 2001 Z28 T56 to SCCA-solo national titles supposedly on the stock synchronizers using synthetic ATF...and pushing to 150K-175K miles on the original transmission.
04-06-2017, 11:32 AM
#15
On The Tree
Thread Starter
My car is a daily, it has never been on a racetrack while under my ownership. I baby the car. I am unsure of which ATF currently lies in the transmission, but I think regular Pennzoil DEXRON 3 will do. The Mobil 1 Synthetic stuff is $10 a quart 
04-06-2017, 04:13 PM
#18
04-06-2017, 04:24 PM
#19
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PITA to find it again, but here is their own words of why Dex III only.
http://www.tremec.com/menu.php?m=110
http://www.tremec.com/menu.php?m=110
04-06-2017, 04:32 PM
#20
I fill from shifter with the fill plug out, once it starts dripping from fill plug, put it in, done. 4 quarts.
it looks like they just changed their website and the link is dead, I cannot find a new path to their FAQ
it looks like they just changed their website and the link is dead, I cannot find a new path to their FAQ