which rear end differential gear oil to use?????

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jimm

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2002
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360 gas
I've an early model 2002 Ram 3500 1 ton dually 360 gas engine that needs a little gear oil added to rear end diff. as it is about an inch lower than fill plug.

I called FOUR different Dodge dealerships to ask what weight and type of oil to use and NONE of them had a clue about the product they sell and service, I talked to their service depts. and their parts depts. and nobody anywhere at Dodge could answer my simple question.

Then I found my owners manual which said to use 90 wt. and my Haynes shop manual said to use a multi weight. The Oreily auto parts store did'nt have any 90 weight so the guy told me 85/90 is the same thing. So I bought it but havent used it yet so it can be returned.

I wanna treat my truck the best possible so now I'm here to ask what is the very best thing to top off the level in the rear diff on my one ton.

I could'nt find out if it's a limited slip from anybody and if needs that special oil or not.

I imagine it has the stock fluid in it as it only had 60K on it when I bought it, now it's at 80K and an inch low


Any help/knowledge greatly appreciated.
 

DILLIGAF

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Your fist mistake was calling a stealersh!t.

Just go to the Amsoil website it will tell you what you need.
 

danielmid

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CoachK23

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I've an early model 2002 Ram 3500 1 ton dually 360 gas engine that needs a little gear oil added to rear end diff. as it is about an inch lower than fill plug.

I called FOUR different Dodge dealerships to ask what weight and type of oil to use and NONE of them had a clue about the product they sell and service, I talked to their service depts. and their parts depts. and nobody anywhere at Dodge could answer my simple question.

Then I found my owners manual which said to use 90 wt. and my Haynes shop manual said to use a multi weight. The Oreily auto parts store did'nt have any 90 weight so the guy told me 85/90 is the same thing. So I bought it but havent used it yet so it can be returned.

I wanna treat my truck the best possible so now I'm here to ask what is the very best thing to top off the level in the rear diff on my one ton.

I could'nt find out if it's a limited slip from anybody and if needs that special oil or not.

I imagine it has the stock fluid in it as it only had 60K on it when I bought it, now it's at 80K and an inch low


Any help/knowledge greatly appreciated.
 

CoachK23

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My mechanic told me some Mexican folks told him they pack it full of ground beef and button it back up He was being serious too!
 

G/T jonny

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An inch below the plug is too low. You may have a seal seeping fluid. the front seal is easy to inspect, axle seals more challenging. Look for an oil film stain. Small metal tag on a cover bolt might tell you if it’s a limited slip, Vin check would tell you for sure.
This would be a perfect time to do a differential fluid change. Pull the cover, drain it, replace cover, put all fresh fluid. probably need additional bottle. That 85/90 will be fine. The synthetic fluids tend to seep past seals a lot easier than the Dino fluids.
 

Mop

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If it's Limited SLip, add Mopar Friction Modifier, before the new gear oil!
 
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