Changing diff fluid

[OffroadX]

Changing the differential and transfer case fluids on a Nissan Xterra/Frontier/Pathfinder
with R200A front diff, TX10A transfer case, and H233B rear diff
Last updated 4/22/02

Items needed:
1/2" drive ratchet or breaker bar, with a short extension

Gear oil:
5 quarts of 80W90 GL-5 gear lube (3 for rear only)
(Rear is 5-7/8 pints, front is 3-1/8 pints, 9 pints total)
4 oz. friction modifier additive for limited-slip differentials if the oil you are
using is not LSD-compatible. Available from your dealer or parts store.

Transfer case fluid:
3 quarts of Nissan Matic "D" or Dexron III/Mercon rated ATF. (2 3/8 qt. capacity)

Large oil catch basin (recycle used oil at a garage or recycling center)
Toothpicks or other implement to remove gunk from threads without scratching
or damaging the threads.
A rag you don't care about getting smelly oil on.
A hose that fits over the nozzle of the gear oil bottle, or some sort of
pump, in order to reach the fill hole.
(hose should be too long to fall completely into the housing!)
This is the pump I have, works like a charm:
http://www.harborfreight.com/cpi/cta...emnumber=37739

Optional items:

Metric socket to remove front sway bar.
Thread sealer:
Permatex #14A Thread Sealer w/ Teflon (part #80631)
or Permatex High Performance thread sealer (part #25117)
or equivalent. Teflon tape is not recommended.

Important note: Do not open the drain plug without first verifying that you can
open the fill plug. You do not want to discover the fill plug is frozen after
you have emptied the unit!

Park the vehicle on a level surface before beginning.

Transfer case:
Locate the fill plug on the rear of the unit (on the left half) and open it.
Loosen but DO NOT REMOVE the drain plug at the lower front of the left half.
It should be loose enough that you can finish removing it with your fingers.
NOTE the when the drain plug is removed, the fluid will GUSH out and shoot a
good 2+ feet away. Lift your catch basin to the drain hole and be prepared
to catch the stream!
Remove the drain plug and let the fluid drain completely.
Inspect the drain plug for metallic "fuzz" and roughly note how much is present,
take a picture if you like. This is for possible documentation of any
wear problem should it ever arise. Some fuzz will be present regardless.
Wipe off the fuzz from the drain plug, and clean the threads of both plugs and
holes with the toothpick, taking care not to break the toothpick into
the housing.
If you are applying sealant, twist your rag into a point and shove a portion into
the drain hole to wick up some of the remaining oil. This is to lower the
level a bit below the lip of the drain hole so the threads can be cleaned.
Wipe the threads of the drain hole and drain plug dry.
Completely fill the threads of the plug with sealant if you are using it.
Install the drain plug, tightening it to 25 ft-lb. Wipe away excess sealant.
Add nearly 2 full quarts of fluid. I found a $10 hand pump to be very handy.
Continue adding fluid in small amounts, checking the level with your finger via
the fill hole opening. It should rise just to the bottom of the opening.
(we want the threads to be oil-free if using sealant)
I was only able to add 2 quarts total, I presume the other "half" of the
transfer case retained some of the old fluid. Visually it doesn't seem
that all of the fluid can drain towards the drain hole from the other half
of the unit.
Clean the threads of the fill hole, wick excess oil with rag if needed.
Apply sealant to fill plug, install, and tighten to 25 ft-lb.

Rear differential:
Lower and remove the spare tire if it is stored under the rear end.
Open the fill plug.
Place catch basin under diff.
Open the drain plug and let the oil drain into the basin.
Inspect the drain plug for metallic "fuzz" and roughly note how much is present,
take a picture if you like. This is for possible documentation of the
classic "diff whine" problem should it ever arise. Some fuzz will be
present regardless.
Wipe off the fuzz from the drain plug, and clean the threads of both plugs and
holes with the toothpick, taking care not to break the toothpick into
the differential housing.
If you are applying sealant, twist your rag into a point and shove a portion into
the drain hole to wick up some of the remaining oil. This is to lower the
level a bit below the lip of the drain hole so the threads can be cleaned.
Wipe the threads of the drain hole and drain plug dry.
Completely fill the threads of the plug with sealant if you are using it.
Install the drain plug, tightening it to 45 ft-lb. Wipe away excess sealant.
Add the proper amount of friction modifier if needed, then add 2 full quarts of oil.
Continue adding oil in small increments, checking with your finger along the way,
until the level is just below the bottom of the fill hole.
(we want the threads to be oil-free if using sealant)
Clean the threads of the fill hole, wick excess oil with rag if needed.
Apply sealant to fill plug, install, and tighten to 45 ft-lb.

Front differential:
Same as the rear, but the fill hole is hard to access. Removing the front sway
bar may be helpful. You will need a short extension to reach the plug
regardless.
When adding oil, 1 full quart may be added before you begin checking the level with
your finger.


That's it. Give any sealant some time to set up, then drive a while and check for
leaks. Keep checking for leaks for a week or two to be safe.

Good luck,
Brent Scott / OffroadX / XterraGuy / likexterra
[email protected]

[KillerX]

(hose should be too long to fall completely into the diff!)

or should it be "hose should *not* be too long..."?

Maybe "hose should be *very* long..."?

[xterra2k]

I believe, that the hose should fit into the hole for the front diff but it should be long enough so that you don’t drop the hose completely into the front diff. which could be a pain to get out.

[OffroadX]

Hose should be long enough that, should it fall off the bottle or pump and into the opening, a portion will remain outside the housing so you can pull it out. If not, good luck fishing it out. Someone (not me) learned the hard way.

Brent

[rcooke]

I used a two foot extension on my 1/2" drive and still could not break the front diff fill plug loose. Any suggestions?

[OffroadX]

It's a bitch to do it by hand since you can't keep the leverage directly along the extension's axis. What you need is to stop by a garage somewhere and slip someone a few bucks to hit it with an impact gun for ya...

Brent

[mquaack]

Any luck on the front differentail plug getting loosen by impact wrench? I'm having the same problem.