Synthetic Transmission fluid
01-08-2006, 08:47 AM
#1
Melting Slicks
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Synthetic Transmission fluid - not allowed??
Posted from the C5 area, terlox was the original poster. Tremec says that it is not recommended - is this still true? I've done synethetic in several transmissions and it was always a wonderment in transformation.
I have my 4 quarts of Redline synthetic Dextron in hand and was just about to make the change any thougths? Tell me not to do it!
I have my 4 quarts of Redline synthetic Dextron in hand and was just about to make the change any thougths? Tell me not to do it!
I'll be doing a tranny fluid change tomorrow and I was reading through some old posts to determine what kind of fluid to buy. I came across quite a few posts where members had switched to synthetic tranny fluid: Mobil 1, Royal Purple, or Amsoil seem to be among the most popular choices. After reading through several threads it looks as though most members have switched to Synthetic ATF without a problem however there were a few who said switching from regular to synthetic ATF could cause problems.
To eliminate the guess work I went straight to the source - I called Tremec themselves and spoke to one of their technical support agents. I told him I have a '00 Corvette with a T56 transmission and asked if switching to synthetic fluid is something they recommend. He told me flat out that no, they don't recommend using synthetic fluids in any of their Tremec transmissions. He said it causes problems with the blocker rings and eats away at various glues that are used inside the transmission. He said that they only recommend using Mercon Dexron III ATF in all of their Tremec transmissions.
I was a bit shocked to hear this being as so many members on their board had made the switch to synthetic transmission fluid. However Tremec themselves does not recommend using synthetic tranny fluid so I'm sticking with standard Mercon Dexron III ATF.
To eliminate the guess work I went straight to the source - I called Tremec themselves and spoke to one of their technical support agents. I told him I have a '00 Corvette with a T56 transmission and asked if switching to synthetic fluid is something they recommend. He told me flat out that no, they don't recommend using synthetic fluids in any of their Tremec transmissions. He said it causes problems with the blocker rings and eats away at various glues that are used inside the transmission. He said that they only recommend using Mercon Dexron III ATF in all of their Tremec transmissions.
I was a bit shocked to hear this being as so many members on their board had made the switch to synthetic transmission fluid. However Tremec themselves does not recommend using synthetic tranny fluid so I'm sticking with standard Mercon Dexron III ATF.
Last edited by Steve Germany; 01-08-2006 at 10:38 AM.
01-08-2006, 11:42 AM
#3
Le Mans Master
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As per the Service Manual, the required lub for the Tremec is:
Dexron III, Specification "H".
I use Mobile 1, Synthetic, Dexron III, Spec H. It is non corrosive, and meets or exceeds all of the factory specifications.
I am not aware of any "glue" in the T56.
Dexron III, Specification "H".
I use Mobile 1, Synthetic, Dexron III, Spec H. It is non corrosive, and meets or exceeds all of the factory specifications.
I am not aware of any "glue" in the T56.
Last edited by calemasters; 01-08-2006 at 12:09 PM.
01-08-2006, 11:49 AM
#4
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CI 1-4-5-8-9-10 Vet
St. Jude Donor '03,'04,'05,'07,08,'09,'10,’17
Don't do it based on my story, because I'm just going from memory. But I seem to remember from the C5 board that GM said to only use Dexron III, Specification "H". And yet, when people complained about a notchy feel when shifting, the official GM fix was to replace the fluid with synthetic 
01-08-2006, 12:18 PM
#5
The earlier C5 transmissions had problems with synthetic. Synthetic is fine to use in the later years...I've used nothing but Mobil1 synthetic ATF since the car was 6 months old (2003 Z06). I remember Subdiver had comments on why certain synthetic ATF's will damage the Tremec; I also remember that he said that Amsoil and Mobil1 ATF's are both good ATF's for the Tremec (I forgot starting with what year of manufacture). By the way, Dexron III can be both synthetic and nonsynthetic. Another product that you can use is GM Synchromsesh; have Mr. Goodwrench put it in; if anything goes wrong, I would imagine that Mr. Goodwrench would be responsible.....similar to a crushed AC Delco oil filter that damages your engine. Fram filters will also pick up the bill if your engine is damaged from a defective filter.
01-08-2006, 12:51 PM
#6
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There is a good synopsis of the info available on this issue in this thread:
http://forums.corvetteforum.com/show...7&forum_id=103
Scroll down to the section titled Tough Shifting
I've also read elsewhere, but can't personally confirm, that the problem with synthetics and early transmissions with the paper blocking rings was related to the basestock of the synthetic fluid in question, specifically ester based synthetics did not seem to do well with the paper blocking rings. PAO based synthetics (group IV synthetics), or highly processed minerial oil synthetics (group III synthetics) seem to be okay with these rings from the posts I've read.
My personal experience is that in my 2002 Z06, which was bought in Aug 2001, has had both ester (Redline) and PAO (AMSOIL) synthetics in the tranny since 800 miles on the clock and I beat the heck out of my tranny. It still has the original, unrebuilt tranny in it.
I do plan on rebuilding it this winter just due to time on it as a precaution. I'll also change out the aluminum shift forks with steel ones while I'm at it.
http://forums.corvetteforum.com/show...7&forum_id=103
Scroll down to the section titled Tough Shifting
I've also read elsewhere, but can't personally confirm, that the problem with synthetics and early transmissions with the paper blocking rings was related to the basestock of the synthetic fluid in question, specifically ester based synthetics did not seem to do well with the paper blocking rings. PAO based synthetics (group IV synthetics), or highly processed minerial oil synthetics (group III synthetics) seem to be okay with these rings from the posts I've read.
My personal experience is that in my 2002 Z06, which was bought in Aug 2001, has had both ester (Redline) and PAO (AMSOIL) synthetics in the tranny since 800 miles on the clock and I beat the heck out of my tranny. It still has the original, unrebuilt tranny in it.
I do plan on rebuilding it this winter just due to time on it as a precaution. I'll also change out the aluminum shift forks with steel ones while I'm at it.
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AMSOIL Catalog
01-08-2006, 01:07 PM
#7
I've been running Redline in various transmissions for years, and have never had a problem. Eats away glues? I don't know who you talked to but that sounds like pure silliness.
01-08-2006, 02:55 PM
#8
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St. Jude Donor '13
Not exactly the same issue, but...
My 2001 C5 with the automatic tranny got an extra tranny cooler and Mobil1 synthetic ATF almost immediately. I beat it up on road courses a few times, autocrossing, manual shifting around town, etc and it's still going fine at 67k miles.
I expect the primary advantages of synthetic would be at high temps, don't know how warm the manual trans gets when driving hard.
My 2001 C5 with the automatic tranny got an extra tranny cooler and Mobil1 synthetic ATF almost immediately. I beat it up on road courses a few times, autocrossing, manual shifting around town, etc and it's still going fine at 67k miles.
I expect the primary advantages of synthetic would be at high temps, don't know how warm the manual trans gets when driving hard.
