would there be any harm in using a Dino 75w90 gl5 to top off a few tenths of a quart in a differential that has a Synthetic 75w90 GL5 of the same brand Valvoline. im asking cause my truck has a transfer case 1.1 quarts,rear differential 3.2 quarts and front differential 1.60 quarts instead of buying a full synthetic at twice the cost just for topping off the couple of tenths needed to fill.
Mixing Synthetic and Dino Gear oil?
- Thread starter jrvn
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It'll mix just fine. Sleep well.
Frankenbrews ROCK!
dont do it, they will fight like Godzilla vs MecaGodzilla. LOL!!!
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Yup, do it all the time.
For example, the differential in the Firebird in my signature holds something like, 2.5 qts(book says 4.25 pts=2qts-8oz) but, in reality it's 2.5 qts. GL-5
So e.g., I'll buy 2 qts of full syn Mobil 1 75w90LS GL-5 and just top off the remaining with the gal jug(I keep'round) of dino 85w90 GL-5.
For example, the differential in the Firebird in my signature holds something like, 2.5 qts(book says 4.25 pts=2qts-8oz) but, in reality it's 2.5 qts. GL-5
So e.g., I'll buy 2 qts of full syn Mobil 1 75w90LS GL-5 and just top off the remaining with the gal jug(I keep'round) of dino 85w90 GL-5.
I had to do this when I changed the rear diff fluid in our 2017 Explorer. There is no drain plug, only a fill plug and due to the rear suspension it's most difficult to remove the diff cover like you would usually do. So it had to be vacuumed out by suction. It didn't get all the FF 80W-90 oil out but I refilled till full with Amsoil Severe Gear 75W-90 25,000 miles ago and all runs fine and quiet. I'll do this one more time to get more of the mix out and replace again with more Amsoil SVG 75W-90 once again.
Whimsey
Whimsey
Dino? Is this 1994?
You can mix different brands of gear oil as long as it is the same quanity of oil. Say for example you mix 75w90 and 85w95 that is not safe.
When I called (and emailed subsequently) Chevron and Mobil support on mixing gear oils of different weights from the same product line, e.g. Delo ESI gear oils - 80W-90 with 85W-140 or Mobil 1 Delvac, both manufacturers reps were categorical about their refusal to recommend the mix practice. I guess, this way they are not able to support the certifications and some other claims - not the end of the world for a non-commercial casual user. Depends on application, of course.
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