ATF in manual transmission?

Messages
124
Location
Cape Town , South Africa
I checked the oil level of my manual transmission after the mechanics had changed my clutch and I noticed the oil is red. Red is usually ATF right? How serious is this should I take it back and get them to change it or is it okay to drive like this?
 
Messages
702
Location
Portland, Oregon
usually red yes. i would return it or at the very least have them prove to you they put the correctly rated fluid on there. as a tangent to this thread i used to admix a little bit of atf into my mt to correct winter starup shifting. i rep d the transmission at my clutch change and no longer need to do this. check your manual to see what fluid yor mt takes. maybe it takes atf.
 
Messages
702
Location
Portland, Oregon
MT fluid should have that distinct stinky sulfur smell, so I wonder if you could do a smell test. However with transmission flushes, they are usually partial flushes, so even if they put ATF in there you'd still smell the old transmission fluid; just perhaps not as strong. But why not go to the dealer and talk to them about it. Maybe i turns out their MTF is red in which case they should be able to show you the bottle or barrel with the red fluid.
 
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19,479
Location
Chicago Area
It is almost a sure thing that ATF is in your tranny. [But some very high end manual trans fluids are reddish!] ATF is used in LOADS of manual trannys/transaxles nowadays. I do not believe it is best, but just adequate to pretty good. A dedicated manual trans fluid is all I will use.
 
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5,024
Location
Southeast
late '80's hondas used 5w-30 in their MTs. Think my '86 escort wanted EO as well. I had a syn 75-90 weight MT fluid.... dyson synlube II that was red in color. M
 
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19,479
Location
Chicago Area
So why ATF? Mostly because of costs to the mfr. The same fluid is for manual trannys, transfer cases, power steering, and auto trannys. And only one fluid to keep in stock. ATf can help in very cold weather for shifting - simply because is is so thin. And that thin ATF also helps a little in fuel economy. But is NOT the best. It is NOT what engineers say is the pinnacle of protection and shifting.
 
Messages
1,095
Location
New Zealand
I first heard of ATF being using in manuals in 1974. It's still a GL-4 gear oil so if the viscosity is sufficient for the gear tooth loading than I certainly don't see a problem and it can only make the shifting better.
 
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19,479
Location
Chicago Area
Originally Posted By: aquariuscsm
Tremec told me their manual trannies have to have ATF because of needle bearings and carbon fiber synchros.
Yes, there are a few trannys that need specific ATF. So ATF is a reasonable choice for them. But many of those who own such trannys have success with dedicated manual trans fluid.
 
Messages
19,479
Location
Chicago Area
Originally Posted By: Kiwi_ME
I first heard of ATF being using in manuals in 1974. It's still a GL-4 gear oil so if the viscosity is sufficient for the gear tooth loading than I certainly don't see a problem and it can only make the shifting better.
ATF not aGL4 gear oil [Redline does make a special one], and there is no reason for it to shift better than specially friction modified manual trans fluid. And ATF has no extreme pressure or anti wear additives.
 

JHZR2

Staff member
Messages
46,307
Location
New Jersey
Yeah, lots of old threads on this. My 91 BMW is specced for ATF. Ive found that Amsoil MTF (not the 75w-90 one, the other one) has done wonderfully. Redline used to get notchy after a year or so, amsoil stays very consistent. FYI.
 
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