Recommended Gearbox Oil

[Flatsix]

Just finished the installation of a lightweight flywheel and SACHS sport clutch for my 318is and am now wondering what type of gearbox oil I should use for tranny fill.  Shop manual indicates that I see my dealer.   Dealer recommended Dexron III ATF as does my cheapo Haynes manual.   Any recommendations/other suggestions?  Currently I am eying Castrol Dexron III ATF fluid.   I am also less keen on synthetics as well.  

Note that vehicle is a 91 318is with Gtrag 5-speed gearbox with 130k on drivetrain.  Gearbox shifts smooth and currently does not leak.  

Flatsix

[m44power]

im running BP Dextron III thes it gets hot i have lot of noise then its cold its realy hard to shift DONT USE IT !!! im gone change it very soon....  maybe next time im gone use some motorkote some special product to mix with gearoil

[nuvolarossa]

I need to change it too. I have a little leak, and it's starting to be hard to shift too.

[ecpreston]

Don't know why you're leery of synthetics, but I've personally had a lot of good luck with both Redline MTL and Silkolene Silktran in E30 transmissions. Light enough for street use, heavy enough for the track.

[Eurospec]

This topic has been covered in the past. You'll find the search engine to be very helpful.

[318idol]

Just use ATF.  Synthestics are a waste, amd at least in my case, the tranny shifts more smoothly with ATF.

[AL GReeNeRy]

i used Redline ATF with D4.  works great.  i grind gears every now and then and it still shifts smoothly regardless

[AL GReeNeRy]

what flywheel did you go with and whered you get the sport clutch upgrade

[JHZR2]

i used Redline ATF with D4.  works great.  i grind gears every now and then and it still shifts smoothly regardless

That is what I use.  make sure it is the right API spec - gear oil for diffs will leach and attack the soft metals in the synchros, etc., and destroy your gearbox.  Redline D4 has a much better additive package than standard Dex III for extreme pressure/anti-wear, and I would use it with confidence.

Dexron VI is far more shear stable than Dexron III, if you must be anti-syn, which is inherently wrong these days because ATFs now have syn (group III and group IV) components, at least go with Dex IIIH or VI, which are at least semi-synthetic, ad maintain their properties better.

JMH

[Flatsix]

Had Jim Rowe at MM machine a 325 flywheel down to 9.5lbs.  Also grooved ring gear.

[Flatsix]

Had Jim Rowe at MM machine a 325 flywheel down to 9.5lbs.  Also grooved ring gear.