View Poll Results: Which fluid is best for a M12 T56?
Redline D4 ATF
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53
8.85%
Royal Purple Syncromax
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179
29.88%
GM Syncromesh
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154
25.71%
OEM Dexron III ATF
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213
35.56%
Voters: 599. You may not vote on this poll
Which T56 fluid?
#81
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Since I am not all up to speed on this.....Dextron III is dino oil.....what's Synchromesh....is it synthetic? If so, then I guess it's out of the question for me since I have a 98, right?
Manny
Manny
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Originally Posted by MannyZ28
Since I am not all up to speed on this.....Dextron III is dino oil.....what's Synchromesh....is it synthetic? If so, then I guess it's out of the question for me since I have a 98, right?
Manny
Manny
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I guess since I really never had a problem shifting, I'll be on the safe side and just use Dexron III. They have the Valvoline brand at the local Adavance Auto Parts, so I guess that will suffice. Should I take the normal version or the one for older trannys? I got 52k on mine, and this is the first time changing the fluid.
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Just want to clear up a common misconception: Dexron III is a specification, not an actual fluid fill.
For example, the OEM fill in the T-56 F-bodys was a dino Dexron III rated ATF.
However, and this is just an example, Mobil-1 Synthetic ATF is also Dexron III rated. Given, it is a synthetic rather than a dino, but it does carry a Dexron III rating. Here's the current link: Mobil 1 Synthetic ATF Product Data Sheet
There are other fluids that owners of vehicles that have a T-56 use though that are not Dexron III rated, such as Pennzoil Synchromesh (I just picked on Pennzoil as their website is laid out well): Pennzoil Synchromesh Fluid Product Data Sheet
Just wanted to clear up the difference between what I think the "use Dexron III only" advocates are getting at...I think what their really trying to say is use what the OEM fill was...and that'd be a dino Dexron III rated fluid...
...I have to be honest and say I don't agree...just thought it be good to distinguish between "Dexron III" and "dino Dexron III", as they are not the same thing...
Chuck
For example, the OEM fill in the T-56 F-bodys was a dino Dexron III rated ATF.
However, and this is just an example, Mobil-1 Synthetic ATF is also Dexron III rated. Given, it is a synthetic rather than a dino, but it does carry a Dexron III rating. Here's the current link: Mobil 1 Synthetic ATF Product Data Sheet
There are other fluids that owners of vehicles that have a T-56 use though that are not Dexron III rated, such as Pennzoil Synchromesh (I just picked on Pennzoil as their website is laid out well): Pennzoil Synchromesh Fluid Product Data Sheet
Just wanted to clear up the difference between what I think the "use Dexron III only" advocates are getting at...I think what their really trying to say is use what the OEM fill was...and that'd be a dino Dexron III rated fluid...
...I have to be honest and say I don't agree...just thought it be good to distinguish between "Dexron III" and "dino Dexron III", as they are not the same thing...
Chuck
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When I had my trans rebuilt for the guy that rebuilt it (local shop) told me to run a 10w-30 synthetic oil in it. I argured with him for a while about it. Needless to say I tried running 10w-30 in it and was amazed on how much better the trany shifted. So for I have 15K miles on the car using Oil in the trans rather than Dexron III. Anyone else ever heard of this?
Chris
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Originally Posted by silver98formula
When I had my trans rebuilt for the guy that rebuilt it (local shop) told me to run a 10w-30 synthetic oil in it. I argured with him for a while about it. Needless to say I tried running 10w-30 in it and was amazed on how much better the trany shifted. So for I have 15K miles on the car using Oil in the trans rather than Dexron III. Anyone else ever heard of this?
Chris
Chris
thats very intresting, did u use 10w30 from the get-go? or did u use dexIII then switch to 10w30?
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Not that these other manuals are related to the T-56 other than their manuals themselves, but back in high school my buddy inherited this older Toyota truck that called for 5W-30 in it's manual....and I'm pretty sure, but not certain, that another guy I know in his 89 (?) Dodge Spirit also called for a 5W-30...
...basically, they just used 5W-30 motor oil, and never had any problems that I heard about.
So, using a 30 weight motor oil in a manual isn't unheard of...using it in a T-56 though is something I haven't seen debated...![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
For reference, I believe the ATF's are in the 20 weight range...with most of today's xW-30's in the low 30 weight range. So, from a weight standpoint, Mobil-1 5W-30 or 10W-30 really isn't that far away from the Synchromesh fills that many here (and elsewhere) are running.
As an edit, ATF does expand when it get hots...while I don't think motor oil does (at least not to the degree ATF does, it motor oil does at all). It could be possible, although I'm not sure how anyone would go about finding out, that GM knows that as the ATF expands - as in the fluid is now taking up a greater volume of space - it reaches previously dry or splash lubed parts of the transmission and starts lubing parts by boundary lubrication, or at worst, barrier lubrication. Just a thought...anythings possible...
Chuck
...basically, they just used 5W-30 motor oil, and never had any problems that I heard about.
So, using a 30 weight motor oil in a manual isn't unheard of...using it in a T-56 though is something I haven't seen debated...
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
For reference, I believe the ATF's are in the 20 weight range...with most of today's xW-30's in the low 30 weight range. So, from a weight standpoint, Mobil-1 5W-30 or 10W-30 really isn't that far away from the Synchromesh fills that many here (and elsewhere) are running.
As an edit, ATF does expand when it get hots...while I don't think motor oil does (at least not to the degree ATF does, it motor oil does at all). It could be possible, although I'm not sure how anyone would go about finding out, that GM knows that as the ATF expands - as in the fluid is now taking up a greater volume of space - it reaches previously dry or splash lubed parts of the transmission and starts lubing parts by boundary lubrication, or at worst, barrier lubrication. Just a thought...anythings possible...
Chuck
Last edited by chucky2; 12-02-2005 at 10:21 AM.
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Originally Posted by silver98formula
After the rebuild I started to use Mobil 1 10w-30. Before that I used Dex. III
Chris
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I put GM synchromesh in mine today - amazing how smooth it shifts now!
Part no. 12345349 (without friction modifier).
I first tried BP Autran DX then Agip ATF. Both are Dexron III specified.
BP is mineral and it wasn't too bad, Agip is semi synthetic and it felt more notchy and easy to grind.
Somehow my 98 tranny likes the synchromesh wich is thicker than the other Dexron III type oils.
It doesn't shift faster but smoother![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
Stefano
Part no. 12345349 (without friction modifier).
I first tried BP Autran DX then Agip ATF. Both are Dexron III specified.
BP is mineral and it wasn't too bad, Agip is semi synthetic and it felt more notchy and easy to grind.
Somehow my 98 tranny likes the synchromesh wich is thicker than the other Dexron III type oils.
It doesn't shift faster but smoother
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Stefano
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Originally Posted by NOBR8KSS
Anybody use this stuff? Redline MTL
http://www.redlineoil.com/products_g...57&subcatID=18
I saw it on one of the TV shows over the weekend and was curious about it.
http://www.redlineoil.com/products_g...57&subcatID=18
I saw it on one of the TV shows over the weekend and was curious about it.
Now at 212,000 miles I've been told to use Redline MTL... which makes sense considering the description specificly mentions MTL's intended use in Honda trannys. It's classified as a 75W/85W gear lubricant, which viscosity wise is equivalent to a 5W30 or 10W30... right in line with the mentioned engine oils here. However anyone using engine oil in a tranny is taking a huge risk IMO. Redline specificly calls out this back-woods band-aid as problematic citing sheer strength and coefficent of friction. If you look at their graph in the tech sheet you'll see that tranny gear speed below 750 RPM causes significant increased levels of friction in the engine oil fill (higher speeds are less of an issue).
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Originally Posted by demonspeed
Although I do not know what makes up the formulation for Synchromesh, it's my understanding that it's not synthetic.
it is an amber colored, light bodied base product that is a partially SYNTHETIC manual transmission fluid"
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Originally Posted by dailydriver
As far as there being a synchro material difference between model years goes; take it for what it's worth, but when I questioned the Tremec tech on this he said ALL of the LS1 T56s used the same material for the synchros, only the LT1 cars used anything different. Again, maybe someone who has actually taken apart/rebuilt different year LS1 T56s can come on here and concur or refute this statement??
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Originally Posted by bshell
Can anybody verify this?
both T56, different manufactures
its also been rummered of the 01-02 t56 having different synchronizer and blocker ring material.
who REALLY knows if this statement is true. after my transmission was rebuild 6 months ago i called the dealership to see if the part numbers for a 00 and a 02 where the same for those parts, and they were.
???
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