Gear lube

[tallpaul]

I tried looking before posting this, but what brand do you guys recommend for breaking in my gears? I know I need 80W90 and 2.2 qts. Do I need a friction modifier? I don't have a posi, just the factory carrier and frpp 4.10 gears.

[RF Overlord]

All Marauders have a "posi" from the factory. Ford calls it "Trac-Lock"

Ford also revised the spec so you should be using 75W-140 synthetic. Most of the major fluids have friction modifier already in them now.

[babbage]

I tried looking before posting this, but what brand do you guys recommend for breaking in my gears? I know I need 80W90 and 2.2 qts. Do I need a friction modifier? I don't have a posi, just the factory carrier and frpp 4.10 gears.

Factory is Trak-lok so yes you have it. Put in a tube of it. 80W-90 should be fine.

First three heat cycles are critical. After 4.10 drive normally for 10 minutes, then stop get out and touch the rear diff cover. It will be hot enough to burn your hand.

Wait 30-40 minutes for it to cool completely then do 2 more runs at 10-15 minutes tops. I would then drive normally for another couple hundred - then dump the pumpkin and go with a nice 75w-140 full synthetic.

[tallpaul]

Thanks everyone for the help.

[fastblackmerc]

Use the Ford recommended 75w140. If you use a synthetic lube you don't need to add anything.

FYI... the Ford shop manual makes no mention of any break in needed. I wouldn't drive for any long distance at a constant speed for the first 100 - 200 miles.

[blazen71]

I've never heard of changing the diff fluid after a "break-in" period. Some people are so stupid.

[babbage]

I've never heard of changing the diff fluid after a "break-in" period. Some people are so stupid.

Ignorance is bliss. I'm not going to explain it to you.

[tbone]

75w140 and just drive it.

[fastblackmerc]

Ignorance is bliss. I'm not going to explain it to you.

I'd change the fluid after about 100 - 200 miles to get rid of anything left in there from the rebuild / new gears.

[blazen71]

I'd change the fluid after about 100 - 200 miles to get rid of anything left in there from the rebuild / new gears.
There is nothing left