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another dex3 question...

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Old 01-17-2010, 07:01 PM
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a little background; my camaro has the cold temp grind going into 3rd and 4th gear, but is fine when it warms up. after a little research it seemed that the fluid was to blame. i didnt know what it had in it before but i wanted to change it out to dex3. all the auto stores around dont seem to carry it, but have some substitute... i went with oreilly atf that says for use on gm vehicles requiring dex3, and ford requiring mercon. anyway, just wrapped up the change, and it still grinds. did i get the wrong fluid? is there a better or ACTUAL dex 3 out there?
Old 01-17-2010, 07:52 PM
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From what I heard, the license to dexron III wasn't renewed with GM/Ford some time ago. I found that Castrol has a dexron III for older domestic vehicles. I've never used it but have several bottles in the garage for the next fluid change. It sounds like you have the same dexron III fluid.
Old 01-19-2010, 06:08 PM
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ill look into the castol. has anyone used anything on the market now and cured the grinding?
Old 01-19-2010, 11:40 PM
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Originally Posted by GQ
ill look into the castol. has anyone used anything on the market now and cured the grinding?
The comment about Dexrons license expiring is correct. GM no longer licenses any DEXRON fluid. THats not to say that there are not suitable fluids available that still satisfy the Dexron spec. Valvoline makes DEX/MERC and Castrol has a DEX fluid as well. Do not use DEX VI as it is not intended for most manual transmissions( too thin). Warren oil ( walmart) makes a DEX/MERC as well.

If you want one of the better Dexron rated fluids for your manual trans look into Redline D4 ATF. It is a synthetic and carries a GL-4 gear rating. Much better than any conventional dex fluid. It is also an ester based ATF and as such can handle extreme temperatures. I have used it for years in my T-56. The only drawback is you have to in most cases order it and it can be expensive.

Further I do not believe your problem is fluid related. Most all Dexron fluids are very tight with respect to the specs given for the fluid. Most have a Vis @ 100°C, cSt of about 7.5-7.6}. Friction modifiers and such will also be very similar between brands. If the fluid was a DEX III and you changed it without a change in the grinding action then that usually means its mechanical in nature.

Last edited by 355TurboLT1; 01-19-2010 at 11:49 PM. Reason: addition
Old 01-20-2010, 04:46 PM
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im concerned it may be mechanical also. but i've read several threads of people curing cold temp grinding by switching to dex3, and am remaining optimistic in believing my car will be as well; because of the fact that the car shifts fine when its warmed. i want to give it a shot with the correct fluid just to make sure before i start looking into the expensive venture of a rebuild...



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