Transmission Fluid Opinions

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slackern
Posts: 2
Joined: Mon Sep 24, 2018 6:48 pm
Location: Sweden

Transmission Fluid Opinions

Post by slackern »

Hi

Its time for a transmission fluid change on my 635-88 (4hp22-EH).

What type of fluid (brand) do you use? Any personal favorites?
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OnTheFritz
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Location: Monroe, MI

Re: Transmission Fluid Opinions

Post by OnTheFritz »

I recently did a fluid drain on my autobox as well, and I just used some bog standard STP Dex III ATF. From all the digging and reading of various forums, I found the general consensus to be that you don't gain much from crazy additives or even name brand vs generic brands due to the Dexron/Mercon certifications being quite stringent to begin with. Based on those people's experiences, I chose to follow the "whatever's cheapest is the best" approach. I was really interested in the Redline D4 ATF, but not at over twice the cost plus shipping! :shock: Maybe someday if I feel like going far above and beyond
8/87 635CSi A, #3266516
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slackern
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Joined: Mon Sep 24, 2018 6:48 pm
Location: Sweden

Re: Transmission Fluid Opinions

Post by slackern »

The Redline D4 ATF looks lika a good quality oil with nice temperature characteristics. Will check with my reseller.
Or maybe the Castrol Transmax Dex III Multivehicle is another option.
EdwasRed
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Joined: Tue May 31, 2016 2:23 pm
Location: St Louis, MO

Re: Transmission Fluid Opinions

Post by EdwasRed »

I am currently swapping my Getrag 280 for a 265/6. Had a conversation with Jim Rowe of Metric Mechanics and his advice was to use the least expensive ATF fluid I could find!?! I'll let you know once I am done with the swap.
1985 635CSi M Euro M88
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Brucey
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Re: Transmission Fluid Opinions

Post by Brucey »

In an autobox any certified Dexron III will work OK. There may be marginal gains to be had in using another fluid.

However in a manual getrag box I would probably choose to use something different from ATF; ATF has viscosity characteristics that suit torque converters, and arguably you can do better than that for a manual transmission fluid. I think Redline do a fluid of this sort (i.e. for manual gearboxes that normally use ATF) and IIRC on their website is an explanation that goes into more detail why this is a good idea. Users report less baulky shifting when the gearbox is cold, IIRC.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
EdwasRed
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Location: St Louis, MO

Re: Transmission Fluid Opinions

Post by EdwasRed »

Brucey wrote: Wed Sep 26, 2018 7:28 pm In an autobox any certified Dexron III will work OK. There may be marginal gains to be had in using another fluid.

However in a manual getrag box I would probably choose to use something different from ATF; ATF has viscosity characteristics that suit torque converters, and arguably you can do better than that for a manual transmission fluid. I think Redline do a fluid of this sort (i.e. for manual gearboxes that normally use ATF) and IIRC on their website is an explanation that goes into more detail why this is a good idea. Users report less baulky shifting when the gearbox is cold, IIRC.

cheers
To be clear, my conversation with Metric Mechanics was about the 265. He stated that they use and recommend ATF fluid for their manual transmissions. He said that some other manual transmission oils are too slick for the synchros to work efficiently.

It sounded odd at the time but they are in the transmission business.
1985 635CSi M Euro M88
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