Accidentally put Transfer Case oil in Rear Diff

sirdumpsalot · Mar 20, 2022

Changing my rear diff fluid today and I pulled a real genius move and started putting transfer case oil in instead of the rear diff oil. I caught my mistake when I had about 1 quart in there (the red gave it away), immediately drained it, flushed some of the correct stuff through until I couldn't see any red. Filled it up correctly with limited slip additive, drove it a few miles, drained and filled it correctly again. My question is:

Should I get it rebuilt or anything?
Flush it again?
Stop worrying?

In my defense, the bottles were shaped the same way.......

G-Ride990 · Mar 20, 2022

If you did a drain and fill/flush you should be totally fine.

What oils did you mix up? As in brands and weights

sirdumpsalot · Mar 20, 2022

Put about 1 quart of MOPAR BW44-44 in, which I'm having trouble figuring out what viscosity that roughly translates to, but it's red and seemed much lighter.
Flushed and filled it with MOPAR 75w-140 with 5 oz of limited slip additive.

BW44-44: 68089195AA
75w140: 68218657AB

G-Ride990 · Mar 20, 2022

I don't think you have anything to worry about. Especially since you caught it so quickly.

18harvest · Mar 20, 2022

99.99% sure you'll be fine

DILLIGAF · Mar 20, 2022

**** happens, The real tragedy here is you're using OEM fluids...

crash68 · Mar 20, 2022

I doubt you would have done any damage to the differential even if you ran the transfer case lube for several hundred/thousand miles.
Only thing that took damage was the wallet having to buy extra fluid for both.

sirdumpsalot · Mar 20, 2022

Cool beans, thanks guys. You're right, the wasted oil hurts the old wallet. I got a bunch of OEM stuff for a steal from summit racing awhile ago but that deal is long gone...

Junior685 · Apr 14, 2022

zero worries, we use lightweight 10w to wash out diffs when we flush them in the HD world. Helps carry out the debris.

Whiskey13 · Apr 14, 2022

I agree with Crash68 the only real damage is to the wallet. At $18 to $25 a quart its a killer

Socalramfan · Apr 14, 2022

For insurance, if it were me…… as mentioned I’d flush, plus do another oil change after driving it for maybe 100 miles, then drain it again.

Maybe over kill, but I wouldn’t forget that mistake again :waytogo:

Brent 1955 · Jan 26, 2023

sirdumpsalot said:
Changing my rear diff fluid today and I pulled a real genius move and started putting transfer case oil in instead of the rear diff oil. I caught my mistake when I had about 1 quart in there (the red gave it away), immediately drained it, flushed some of the correct stuff through until I couldn't see any red. Filled it up correctly with limited slip additive, drove it a few miles, drained and filled it correctly again. My question is:

Should I get it rebuilt or anything?
Flush it again?
Stop worrying?

In my defense, the bottles were shaped the same way.......

Drain it use brake clean on the inside of the differential blow dry it all out till dry and replace with gear oil and (limited slip oil if you have a limited slip). And one quart of Lucas oil treatment. Doing mine this way haveover400000 miles on my differentials now. And over 600,000 mileson the truck.

GTyankee · Jan 26, 2023

no damage was done, enjoy your ride

pacofortacos · Jan 26, 2023

Nothing to worry about. Drive it and don't look back.
If towing change the diff oil every couple of years, just drain and refill using the drain plug and fill plug. Cheap insurance.

Accidentally put Transfer Case oil in Rear Diff

sirdumpsalot

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G-Ride990

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sirdumpsalot

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G-Ride990

Administrator

18harvest

Senior Member

DILLIGAF

Senior Member

crash68

ACME product engineer

sirdumpsalot

Senior Member

Junior685

Junior Member

Whiskey13

Member

Socalramfan

Senior Member

Brent 1955

Member

GTyankee

Senior Member

pacofortacos

Senior Member

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