J30 Rear End Grease Addition

[sahamm]

1995 J30 w/ 130k miles::

Wanted to add/check rear end grease level. I can find drain plug, but not hole/plug where you can add grease.

Does anyone know where you can add additional grease to the rear end of a J30?

Thanks!

[elwesso]

On the Q, the drain plug is at the bottom, and there is another plug you take out on the top, on the drivers side.....

you should drain/refill... cant remember how much it takes.....

Do you have a FSM?

[DAEDALUS]

You mean differential oil?

[sahamm]

Yeah, I suppose it is oil, but of course it's twice as heavy as regular motor oil. I've just heard it referred to as "grease" for years.

[sahamm]

It is the differential... Sorry for not being clear the first time.

[Q45tech]

"twice as heavy as regular motor oil" at room temperature but only 5 cSt at 300F.http://www.drivetrain.com/redlinedifflube.html

If you do lots of short under 10 mile trips in winter you can gain some mpg by using the Redline 75/90 NS fluid it will pay for itself [extra cost in a year].......$10 quart x 2..................a 2% improvement in cold and general friction should save 14-15 gallons of fuel per 15,000 miles.

130k is a little late hopefully someone changed it at 60k, I change mine every 30k after learning the hard way with diff replacements over the years.

The diff efficiency is critical to rear wheel HP as the diff is very inefficient at low speeds [93%] vs 97% at 60 mph...........the 75/90NS is almost 0.75% better at 60 mph and 4% better at 5 mph.

[sahamm]

Good info, but where's the hole to put it in on the J30?

Thanks!

[vehornr]

you've probably found it by now, but if not it's on the driver's side, fairly high up. it's a b*tch to get the new oil in!

[Q45tech]

Not with the proper pump or even a hand syringe pump. Pretty much all [every car/truck] rear differentials are the same [locations vary] as to the method of draining and refilling.

[vehornr]

yeah, well, it always helps to have the right tools