Opinions Please. Best fluids for 1973 A833 4 spd and 489 case rear?

[73JF1Bird]

Hello. I'm a fluids guy, I can't help it. For years I have been a fanatic about the fluids that go into my vehicles. I'm putting back together my 73 Roadrunner, A833 4 spd and 3.55 sure grip, 489 case rear differential. Are there any latest and greatest fluids that you love and recommend? All feedback is greatly appreciated. Thanks, Curt

 

[Hemi Rebel]

When i got my super bee, it had gear oil in it. Ok if you drive like granny. Didnt work so well when trying to pull off ronnie sox shifts. I changed it for synchroshift 2. Works great

https://www.bgprod.com/catalog/drive-line/bg-syncro-shift-ii/

 

[73JF1Bird]

Thanks Rebel. BG makes some quality stuff. What about the rear diff?

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I had a 69 Roadrunner automatic that I put 100% Chrysler Brand, ATF4 in it. That change definitely made a difference in the way it performed and shifted.

 

[747mopar]

I read a piece on this and basically it said run standard gear oil for it's cushioning properties for longer life. It's like everything else, a trade off. Thicker oil means more protection, thinner oil means less resistance. The one big difference now is the availability of these synthetic oils that offer good protection while improving shifts, I'd go with something like Hemi Rebel suggested (I'm running sychromesh but mines a T56).

 

[73JF1Bird]

Thank you 747.

 

[bigaadams]

The transmission and rear differential are different cut gearing....the hypoid rear gears need oil with sheer properties added...namely a GL5 rated oil by the API Now based on who you talk to...their own reflections and such and the label on many products today..they say the GL5 is retro to the transmissions and states that the additives today are yellow metal friendly...ok...you can choose to believe them or not..your call..you still do not need sheer additives to the transmisiion. NAPA still carries GL1 gear lube per API rating in gallon containers 80W for approx. 15.00 a gallon...the ratings are for a reason...GL2 & 3 are obsolete...but the demand and rating for GL1 still exists..it exists for a reason..

you can read the talking paper by the API or yu can source other papers say, Bob the oil guy.....they are very informative articles..

 

[73JF1Bird]

Thank you for the info Bigaadams!

 

[Meep-Meep]

I like the SWEPCO 201

http://www.swepcolube.com/products/swepco-201-multi-purpose-gear-lube

 

[benno440]

gearbox - 80% 80w90 then 20% ATF works well for me and have also been recommended from many.
489 diff 90w gear oil and that's with a eaton truetrac as well

 

[uwss]

I run Royal Purple in everything; have nothing put great results. You can always call RP.

 

[RJRENTON]

Gentlemen,
For my money and piece of mind, I run synthetic lubricants in the engine (Mobil 1 10W-30), in the A-833 trans (18 spline input shaft) and Dana 60 rear (with 4.10:1 gears) Mobil 85W-90 gear oil. Gear oil has an EP (extreme pressure) additive which is necessary to prevent gear wear. The sure grip clutches in the Dana get along just fine with the Mobil 1 product. The car is stored in the winter, so I do not have to be concerned with shifting issues. Perhaps one may consider an ATF in the trans if racing is a consideration. Replacement parts are just too expensive not to use the best lubrication available and in my opinion they are synthetics. The old adage may apply: oil is cheaper than bearings and gears. But this is just my opinion.
Cheers,
RJ Renton

 

[73JF1Bird]

Thank you all very much for the info! FBBO Members Rock!!!