JRHAWK9

Some interesting stuff, IMO. Confirms what I have been -READING- about how ATF is not the best choice for a manual tranny in terms of protecting the tranny.

http://www.youtube.com/watch?v=m_toE...eature=related

haljensen

Read that back when I had an SRT4. Note that it refers to transaxles, not separate transmission, separate diffrentials like the C6.

Transaxles have an unuasual problem with lubrication, transmission gears require different lubricants than differentials but both sets of gears are in the same case so they have to share a lubricant. Add a limited slip to the diff. and you've added another problem. Since the SRT4 has a Torque Sensing Limited Slip instead of a clutch type the lubrication is very important.

Cliffs notes on the Video above; Mobil 1 10W-40 High Mileage motor oil is recomended for the SRT4 transaxle.

JRHAWK9

Yeah, I agree, however I feel there is some valuable info he's providing which we can use. This being ATF is not the best for the longevity of manual trannys. It provides minimal, at best, protection. It's mainly used to save money during the assembly process. I have been using a manual transmission fluid in my Vette (RP Syncomax) and in my Firehawk (Pennzoil Synchromesh) for quite a while. GM offers a specific manual transmission lubricant as well. We now know why it's not a factory fill.

Anyway, thought it was interesting hearing what I have always thought about why manufacturers do what they do when there maybe other "better" choices. It pretty much all comes down to the bean counters.

JCtx

GM doen't make our transmissions. If you don't trust GM, ask Tremec directly. But making assumptions based on transaxles (or other applications), it's just plain crazy IMO, especially if you're under warranty. You can kill the synchros much earlier with the wrong oil. But to each his own. Good luck.

Bill Dearborn

Been using ATF in C5/C6 manual transmissions for 15 years without any issue. Three cars that were heavily tracked with no transmission issues. Not a single one. If you look at the history of the Borg Warner/Tremec transmission across the board in Corvettes there just isn't any evidence there is an issue with ATF.

Bill

GOLD72

DEX III ATF is the prescribed fluid. Just don't use DEX 6.

JRHAWK9

I forgot this site has the "whatever GM uses" is the best mentality......lol (of course except for the front seats which so many people like to complain about...lol)

I wasn't comparing a transaxle to a standard tranny. It's a fact that ATF doesn't protect gears as well as other fluids on the market can. This is the whole reason behind the numerous manual only tranny fluids out there. I've also heard of and read about GM dealers using a "synchro" type of manual transmission fluid in the TR6060. I realize Tremec is on record stating to use ATF. Do you really think they would state otherwise when GM (and other manufacturers) use ATF in a factory fill for reasons other than what's best for the tranny and service life. There are numerous people using a manual tranny fluid and have much better shifting from it. I know I am one of them. It's not like we are using some risk taking concoction....lol These fluids are recommended in trannys requiring ATF.

I'm also into chainsaws. It's sort of like all the manufacturers "recommending" a 50:1 gas/oil mix when they know damn well 32:1 is better for the saw. They can't "print" this because of the EPA and emissions. One manufacturer actually went on record and stated to use 32:1 regardless of what you read on the saw or in the manual. Using 50:1 mix has been linked to premature big bearing failure on some saws.

I guess the way I look at it is some of the decisions that are made are usually based on more than just what will make a specific component last the longest or what's best for that specific component. I'm guessing if it were just engineers making the decisions we would have better built/longer lasting cars but they would cost a heck of a lot more to build and purchase. I maybe completely wrong, but this is how I see it.