I had dirty rear differential oil!

[outinthewoods]

I know the topic of dirty rear diff oil has come up before, however, my FJ was built 07/07 (previous posts where mainly 06 production) and she only had 8000 mi. on her when I made the switch to royal purple.

I have a had a few water crossings, but nothing I would call extreme.

The oil was milky, with a great deal of sludge/metal shavings on the magnet.

pretty gross for such a new rig.

[DoWork]

I need to do mine badly..... How much oil do i need to put in and what type? A certain type of royal purple?

[ferguson]

check out the "Scuba Driver" threads.

[frogeye]

It's easy to inspect your diff oil. Just take the Bolt out and insert a clear plastic tube and push it in and put your thumb on the end and take it out. You will have a tube of lube to inspect and see if you have any contamination from that last water crossing you did. HTH.

[cruiserlarry]

outinthewoods previously said:

I know the topic of dirty rear diff oil has come up before, however, my FJ was built 07/07 (previous posts where mainly 06 production) and she only had 8000 mi. on her when I made the switch to royal purple.

I have a had a few water crossings, but nothing I would call extreme.

The oil was milky, with a great deal of sludge/metal shavings on the magnet.

pretty gross for such a new rig.

The diff oil should be changed at 500 miles after purchasing the vehicle, IMO. When we do ring/pinion or diff work, we suggest changing after 100 miles or so to rid the diff of any metal shavings from break-in of the new components. Most ring/pinion mfgrs recommend the same. So it's no wonder there was a lot of crud in your diff. Regarding the milky consistency, that's a pretty good indicator of water mixing with the oil, and should be changed ASAP if you see that.

And a side note, diffs, transfer cases, and manual transmissions do not have to wait to switch to synthetics, as is suggested for the engine due to piston ring seating. The sooner the better in any type of manual gear box or diff...

[DEWFPO]

DoWork previously said:

I need to do mine badly..... How much oil do i need to put in and what type? A certain type of royal purple?

~3.1 qts of 75W90 synthetic for the rear diff. It's all in your manual (if you have one).

DEWFPO

[stringmachine]

cruiserlarry previously said:

The diff oil should be changed at 500 miles after purchasing the vehicle, IMO. When we do ring/pinion or diff work, we suggest changing after 100 miles or so to rid the diff of any metal shavings from break-in of the new components. Most ring/pinion mfgrs recommend the same. So it's no wonder there was a lot of crud in your diff. Regarding the milky consistency, that's a pretty good indicator of water mixing with the oil, and should be changed ASAP if you see that.

And a side note, diffs, transfer cases, and manual transmissions do not have to wait to switch to synthetics, as is suggested for the engine due to piston ring seating. The sooner the better in any type of manual gear box or diff...

cruiser larry, i was wondering now soon to roll 20,000 , about 14,000 i had the dealer change mine it was real dark no water . ok that said i just recently changed mine over to 75 90 mobil1 synthetic. so do you think if i change it now every 10,000 that is overboard. or should i now go the full 15,000 inbetween thx

[fj squarepants]

DEWFPO previously said:

~3.1 qts of 75W90 synthetic for the rear diff. It's all in your manual (if you have one).

DEWFPO

I just bought 3 qts of Royal Purple 75w-90. Is it going to be enough given that I probably won't drain that .1 out? Has anyone needed a forth quart?
THANKS

[uphill]

stringmachine previously said:

cruiser larry, i was wondering now soon to roll 20,000 , about 14,000 i had the dealer change mine it was real dark no water . ok that said i just recently changed mine over to 75 90 mobil1 synthetic. so do you think if i change it now every 10,000 that is overboard. or should i now go the full 15,000 inbetween thx

I change mine every 10,000 miles and use Mobil 1 synthetic. It's just what I do. Your results may be different.

Scuba Driver mod -- It's a $30.00 mod and it can save both your rear differential and your e-locker. Unless you're just driving it on pavement as a commuter or you're picking up the kids from school, this mod is a must-do.

[DoWork]

DEWFPO previously said:

~3.1 qts of 75W90 synthetic for the rear diff. It's all in your manual (if you have one).

DEWFPO

Thanks, Im off to get some royal purple and do this now and hopefully do the breather mod this weekend.