Lube change intervals for differential oil...

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16
Location
NY USA
Guys, We have two vintage automobiles (1960s & 1970s) that we use as daily drivers. How often (time or mileage) should the rear axle lube be changed in these vehicles? Is Syntec 80W-90 a good oil to use is these cars?
 
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8,756
Location
RI
50k or 3 years max All my gear oils are changed every 2 years or 30k. Any GL5 gear oil is good enough. I stick with synthetics always.
 
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1,565
Location
Elkridge, MD
 Originally Posted By: Bob_B
We have two vintage automobiles (1960s & 1970s) that we use as daily drivers. How often (time or mileage) should the rear axle lube be changed in these vehicles? Is Syntec 80W-90 a good oil to use is these cars?
You're living my dream. I change the oil in my Chrysler 8.25 and Dana 35 diffs every 20-30K. I use M1 75W-90.
 
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8,859
Location
Texas
 Originally Posted By: Bob_B
Guys, We have two vintage automobiles (1960s & 1970s) that we use as daily drivers. How often (time or mileage) should the rear axle lube be changed in these vehicles? Is Syntec 80W-90 a good oil to use is these cars?
I would say that its reasonable to change it every 50-60k miles in normal use. But I will tell you that American rear axles of that vintage are hugely over-built and can take a ton of neglect. Dad never bothered with that in most of his cars/trucks, and they all saw around 200k and never a failure. The Chrysler 8.25 in my 1973 Satellite got its *first* gear oil change at over 200,000 miles and 15 odd years! And its still going strong and quiet at over 430,000 miles. Heck, it and the power steering pump are about the only 2 totally un-touched pieces left on the car. Syntec 80w90 should be fine.
 
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2,338
Location
Magnolia, TX
I think 30K/2 year intervals is good advice. Without getting into a seal compatibilty debate, I would monitor the seals for leaks after switching to synthetic gear oils (especially PAO). You might consider an Auto-Rx treatment prior to switching.
 

Bob_B

Thread starter
Messages
16
Location
NY USA
Thanks, guys. Based upon what I've read here, I think that I'll stick to dino oil. After all, the Falcon has 133,000 and the Buick has 188000, both on conventional lube, and they're still going, so the stuff can't be too bad...!!!
 
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