rear diff oil

buckeye titan · 08-20-2005, 01:05 PM

how many qt does it take to fill up the rear diff? i was going to use mobile 1
syn 75/140 how much does it cost per qt?

Flight Test · 08-20-2005, 01:48 PM

I changed mine not too long ago and it takes just over 2 qts. Filled until it came out the fill hole. The only place I found it so far is at Pep Boy's for $14.99/qt.

Burly · 08-20-2005, 01:54 PM

2-3/4. Back your truck up on some ramps or some kind of blocks safely and that will allow you to get more in there.

Titan Ken · 08-22-2005, 10:18 PM

$17.99 per quart at Schucks in Oregon for Mobil 1 75w-140 synthetic. Just as others have said, mine took a little more than 2 quarts.

kstitan · 08-22-2005, 10:31 PM

I haven't been under that end of the truck yet. Where is the drain plug? Please tell me it's just a plug on the bottom of the differential, and that you don't have to pull off the differential cover to get the old fluid out. I've got an 04 (Apr. 04 build date) 4X4 that I bought left over in Apr. 05, and now I see from the forum discussions that the differential might not be full of oil, so I'm thinking about changing to synthetic. Should I do the same with the front differential, and the same question: where's the drain on the front one?

uititan · 08-23-2005, 06:24 AM

Drain plugs are on the bottom - no need to remove the cover. I replaced mine with Mob 1 75-140 syn soon after I got it. It is standard on the 05's and there is a TSB for the 04's to have the fluid changed to 75-140 syn. My front diff doesn't get much stress, so I've not replaced it -- did check and it was a bit low. You should at least check the level on the rear. Replacing would probably be a good thing to upgrade to the syn. Try searching on diff fluid and you'll get a bunch of threads. Good luck.

TOK · 08-23-2005, 06:36 AM

Quote:

Originally Posted by Burly

2-3/4. Back your truck up on some ramps or some kind of blocks safely and that will allow you to get more in there.

If you overfill a rear it usually blows out the vent tube and gets on the underside of the truck. I guess this didn't happen with the ramp trick?

uititan · 08-23-2005, 05:59 PM

Quote:

Originally Posted by TOK

If you overfill a rear it usually blows out the vent tube and gets on the underside of the truck. I guess this didn't happen with the ramp trick?

I was thinking the same. Don't think I would suggest forcing more oil in or it will be messy coming out of the axle vent.

titanse05 · 08-23-2005, 06:58 PM

Just changed mine today for the first time at 4800 miles. Everything looked good....the factory fill still had a lot of life in it and the drain plug only had a small amount of shavings on it. Keep in mind that I have an '05 with the factory synthetic and alum diff cover.

It takes just over 2 quarts and I paid $16/quart at AutoZone (only place that carries it locally).
Drain plug = 20 ftlbs
Fill plug = 25 ftlbs

I was surprised on how quick it is finished.

CJ3FLYR · 08-23-2005, 07:03 PM

Quote:

Originally Posted by Burly

2-3/4. Back your truck up on some ramps or some kind of blocks safely and that will allow you to get more in there.

This is old school stuff from eons ago but... Overfilling the rear has a tendency to induce leaks or weeping at the axle seals by the wheels. The level of oil is usually just below the bottom of the wheel seal. Some oil is sloshed out to the bearing, some is 'pulled' out by a spiral groove in the shaft in some cases, in no case that I know of is the oil level at rest higher than the bottom of the wheel seal. Too full may also help the oil to foam, a bad thing. I wouldn't overfill.