maintenance/proper fluids
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maintenance/proper fluids
Posted to general discussions but was re-directed to this forum. Question regarding proper fluids in my '89 with 160,00 miles. I plan on putting in the shop for maintenance, along with oil change and rear end service. Have been using Mobil 5000 5/30 and am considering a synthetic blend or maybe a straight synthetic. No oil leaks but have heard some horror stories regarding a switch at this stage. Also, plan on complete rear fluid change in rear end, using 90-140 valvoline with a separate additive. Your thoughts, opinions and ideas would be appreciated.
Jim
Jim
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Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The correct gear oil for the differential is a 80W-90 GL5 non-synthetic oil and you can add one or two bottles of the GM posi additive. There are some gear oils that have additives in them. Royal Purple and AMSOL are two that some members use.
I would not use the 90-140 weight oil at all.
It's not a GM recommendation for any of their passenger car differentials.
Your current choice of engine oil should be just fine. Does the engine use any oil between changes? I would still be doing changes every 3000 miles even with the Mobil 5000. No reason to change viscosity either A 5W-30 will work fine.
A full synthetic also in 5W-30 will work but it may cause leaks. Synthetic oil will clean much better and that can remove sludge and deposits that have sealed up small leaks. Once that stuff is gone, then the leaks appear.
I would not use the 90-140 weight oil at all.
It's not a GM recommendation for any of their passenger car differentials.Your current choice of engine oil should be just fine. Does the engine use any oil between changes? I would still be doing changes every 3000 miles even with the Mobil 5000. No reason to change viscosity either A 5W-30 will work fine.
A full synthetic also in 5W-30 will work but it may cause leaks. Synthetic oil will clean much better and that can remove sludge and deposits that have sealed up small leaks. Once that stuff is gone, then the leaks appear.
Burning Brakes
Joined: Oct 2009
Posts: 773
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From: Minneapolis MN
The correct gear oil for the differential is a 80W-90 GL5 non-synthetic oil and you can add one or two bottles of the GM posi additive. There are some gear oils that have additives in them. Royal Purple and AMSOL are two that some members use.
I would not use the 90-140 weight oil at all. It's not a GM recommendation for any of their passenger car differentials.
Your current choice of engine oil should be just fine. Does the engine use any oil between changes? I would still be doing changes every 3000 miles even with the Mobil 5000. No reason to change viscosity either A 5W-30 will work fine.
A full synthetic also in 5W-30 will work but it may cause leaks. Synthetic oil will clean much better and that can remove sludge and deposits that have sealed up small leaks. Once that stuff is gone, then the leaks appear.
I would not use the 90-140 weight oil at all.
It's not a GM recommendation for any of their passenger car differentials.Your current choice of engine oil should be just fine. Does the engine use any oil between changes? I would still be doing changes every 3000 miles even with the Mobil 5000. No reason to change viscosity either A 5W-30 will work fine.
A full synthetic also in 5W-30 will work but it may cause leaks. Synthetic oil will clean much better and that can remove sludge and deposits that have sealed up small leaks. Once that stuff is gone, then the leaks appear.
