











Which T56 fluid?
Manny
Manny
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
The Best V8 Stories One Small Block at Time
Chris
Chris
thats very intresting, did u use 10w30 from the get-go? or did u use dexIII then switch to 10w30?
...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...

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; Dec 2, 2005 at 10:21 AM.
Chris
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

Stefano
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).
it is an amber colored, light bodied base product that is a partially SYNTHETIC manual transmission fluid"
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.
???
Do we really share the same tranny or is it different from car to car?



