Differental oil?

[Boostin]

What oil do i need to put in my rear end, it is a stock 8.8 with 3:73. i read somewhere that you put 80-90w with an additive for the trac-lok.

 

[bullitstang1313]

If it has a traction lok in it Ford suggests using a friction modifier along with the 89-90W gear oil. Now a days many of the 80-90W gear oils come with a friction modifier in them already. Lucas gear oil already contains it as well as most synthetics or you can add it in seperately.

 

[89CopCoupe]

80-90 with a tube of standard parts store Limited-Slip additive.

Just a note, if you don't have an aftermarket girdle cover with the fill hole in it, you might want to mix the additive and some gear oil in a small oil bottle to pump it in ... the factory fill plug is not the easiest to get to without spilling half the additive all over the fill area ....

First hand experience

 

[crazypete]

Dont use dino gear oil! That friction modifier stinks so intensely it will curl the paint off the walls. It's like pinetree sweat burnt oil.

Use synthetic 75w-90. It doesnt need friction modifier and even if it gives you 1% extra economy from reduced friction, it will pay for itself very fast.

 

[Boostin]

Well i have access to all the Rotella T 80-90wHD that i need. so i think im gonna use that, cause free is better than 15 bucks a quart

 

[maverick0716]

I use Redline 75W-90 in mine

 

[cobra259]

Well i have access to all the Rotella T 80-90wHD that i need. so i think im gonna use that, cause free is better than 15 bucks a quart

Red line is $8.00 a quart, not $15.00....but hey if your going to steal it, yes that would be cheaper!!

 

[Fishhawk]

I switched to 85/140. Quieted it up nicely. I've found Torco High Performance to be the best. Had to pull the axles last week and got a good look at the gears after 6000 miles and they look as good as the day I put them in.

 

[Shakerhood]

80-90 with a tube of standard parts store Limited-Slip additive.

Just a note, if you don't have an aftermarket girdle cover with the fill hole in it, you might want to mix the additive and some gear oil in a small oil bottle to pump it in ... the factory fill plug is not the easiest to get to without spilling half the additive all over the fill area ....

First hand experience

You can also fill through the axle vent on the P/S as it is alot easier to get to than the factory fill hole.

 

[89MustangGX]

You can also fill through the axle vent on the P/S as it is alot easier to get to than the factory fill hole.

Only question I have is how you will know when it's full.

I have used Mobil-1, Amsoil, and dino stuff. I prefer all synthetics now. Pick one.

 

[HISSIN50]

Only question I have is how you will know when it's full.

I think he does it like people do trans filling (when filling through the shifter base itself). Remove the filler plug and pour through the vent till it starts seeping out the real filler plug.

 

[o2man98]

I thought that ford was now recommending 75w-140 for all their rearends.

 

[DW5.0L]

I use Amsoil 75W90. Its $7.90 Sythetic Gear Oil and has the friction modifier in it. 4 oz friction modifier would be a good idea in non-synthetic gear oil. A little less than 3 bottles will be needed for the gear oil change.

 

[Fishhawk]

I thought that ford was now recommending 75w-140 for all their rearends.

I've heard the same thing. I know my F-350 and Mustang rear ends are much quieter with the thick stuff. The gears also look great after much use.