[BruceJack]

What level do you fill your rear differential to?

I am from old school and would normally fill it until the oil is level to the threads on the filler plug.

The manual says to fill 1/4" to 9/16" below the threads on the filler plug.

 

[powerproman]

Go old school....fill it until it barely starts creeping out of the drain plug threads. Just did my son's differential about a thousand miles ago....no problems doing it the way I described.

 

[Primedlx]

If you have an 8.8 rear end, fill it 3.75 pints (1.8 litres). Then add 4 oz of friction modifier (a small bottle) if a posi.

 

[Bryonl]

What they said!:bigthumbsup

 

[93ksstang]

Fill it to the threads

 

[s197inthe208]

Just squeeze that bottle until it comes out a bit then stop. Easy.

 

[TexasBlownV8]

Worst case if you fill it to the hole and drive it hard, some may come out the vent tube on the axle.
I tend to fill it about 1/4" under the hole.

 

[Ohhitskb]

Quick question, and I don't mean to thread-jack, but what weight (I'm guessing that's what the numbers on differential fluid mean) goes in the rear-end of a 2005-10 GT? I need to change mine out, but I don't know if it's 75w90, 75w140, or 85w140.

 

[sqidd]

What level do you fill your rear differential to?

I am from old school and would normally fill it until the oil is level to the threads on the filler plug.

The manual says to fill 1/4" to 9/16" below the threads on the filler plug.

Go old school....fill it until it barely starts creeping out of the drain plug threads. Just did my son's differential about a thousand miles ago....no problems doing it the way I described.

Fill it to the threads

Just squeeze that bottle until it comes out a bit then stop. Easy.

Worst case if you fill it to the hole and drive it hard, some may come out the vent tube on the axle.
I tend to fill it about 1/4" under the hole.

Old school all the way. And Texas is right, if it's too full it will puke a little out the vent. I find that unlikely though. My 07' is filled to the threads and I have had it out on the roadrace course. It didn't puke a drop. And if it doesn't puke at the roadrace track, it won't.