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Transmission & Oil

What is the best transmission fluid for me to use on my 1971 automatic? Also what is the best oil to be using, as I have original engine in car with 101K on it.

Submitted by: Lawrence McLin


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Again referring to the owner?s manual for the 1971 I used to own the primary recommendation is 5W30 with an optional 10W30. Of course, the 5W30 will flow faster at start-up which will reduce startup wear. That?s important when you consider that anywhere from 80% to 95% of all the wear that occurs on an engine happens during or immediately following start-up. As far as the transmission goes back in 1971 the recommendation was for Dexron transmission fluid but Dexron no longer exists. Actually, several iterations of Dexron (Dexron, Dexron II, Dexron IID, Dexron IIE, Dexron III) have come and gone over the years since 1971 and today we have Dexron VI. Per GM, Dexron VI is backwards compatible for all Dexron levels. So, you?re now looking for Dexron VI in the brand you like. I use and like BG Products full synthetic transmission fluid. Anonymous on 7/1/2017 6:53:46 PM
AL,Will, Mike thanks much! Lawrence McLin on 11/29/2016 7:57:05 PM
I'd use Dexron Mercon 2....I have it in a number of older Vettes with high mileage. Oil : 10/40 High mileage Castrol or Mobil. I'd use the Puralator oil filter too... Mike Anonymous on 11/21/2016 12:49:24 PM
For older cars with the original engines it's important to note if when or if the engines were built or rebuilt the valve seats were hardened. If not then one must use a lead oil additive plus one that has high zinc levels to protect the crank shaft. Hemmings sells an engine oil that meets these requirements. In addition 20w-50 engine oils which are readily available have zinc additives. I prefer Royal Purple engine oil. Anonymous on 11/21/2016 12:40:55 PM
The best transmission fluid to use is ATF Valvoline The best oil to use is Shell Rotella because of zinc. Do not use a synthetic oil as it will wear the cam out fast. William Cantrell on 11/19/2016 7:46:03 PM
You should look for a "dexron" type transmission fluid, which there may be many versions depending upon the brand and its specific GM requirements. I here there is a Dexron VI out that may perform better than previous products, which had problems with maintaining viscosity at high heat levels. You might ask a transmission rebuilder what they recommend since they should be in the loop. As for engine oil, I've had good luck with Chevron Delo 15-40. Keeps oil pressure steady on my '75. Alan Benek on 11/18/2016 11:46:58 PM

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