First Mod, Rear Diff Cover.

Add one more tube of ford friction modifier if it snaps on figure eights

I mean to check if the friction modifier is adequate
Does not really stress the rear end just moves the clutch packs back and forth
Good job and I like the cover

BrewsterGT said:

Do you mean drive the car in a figure eight to stress the diff and check for noise?

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Figure eights are just to get the friction modifier worked into the clutch packs

I was going to install a newer rear cover ( two of them on my 4 wheel drive) with drain plugs to facilitate draining them....
Watched some videos about how they can affect the " flinging" of the lube in a bad way for lubricating the gears.....
I recommend watching these....

limp said:

I was going to install a newer rear cover ( two of them on my 4 wheel drive) with drain plugs to facilitate draining them....
Watched some videos about how they can affect the " flinging" of the lube in a bad way for lubricating the gears.....
I recommend watching these....

Click to expand...

Not sure how a rear cover, especially on a 8.8" rear, could possibly cause any problems with lubing the rear gears.
Thousands of them have been installed and nobody is having premature gear failure from using one.
Now maybe on a 4x4 differential, where the housing/cover is much larger could potentially have an issue. Maybe, if overfilled. And even then, would have to be towing or heavy loads or something. Running empty I doubt there is enough heat/load to cause any damage.

Bullitt347 said:

Not sure how a rear cover, especially on a 8.8" rear, could possibly cause any problems with lubing the rear gears.
Thousands of them have been installed and nobody is having premature gear failure from using one.
Now maybe on a 4x4 differential, where the housing/cover is much larger could potentially have an issue. Maybe, if overfilled. And even then, would have to be towing or heavy loads or something. Running empty I doubt there is enough heat/load to cause any damage.

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I would recommend watching the videos...

TA rear cover on my Coupe for 20 years and zero issues. Also have one on the T-Bird for about the same amount of time and zero issues. I understand what the guy is talking about but he is specifically talking about the flat back covers which does not apply to any (that I know of) of the 8.8 covers. The flat back covers are on the large pickups and the put them on in hopes the cooling fins will reduce the oil temps.

LILCBRA said:

@Bullitt347 - I believe @limp is referring to this video.

View: https://youtu.be/7AmLbGSvESg?si=RRaVB6ArY6b07oiZ

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Truck diffs, much larger. More room for error.
8.8 Ford is a different animal.
For one, the cover is basically identical to the stock one, other than being aluminum instead of stamped steel. The inside dimensions is pretty much the same. Not a concern at all.
You would probably be surprised that I only run 1 qrt of gear lube in the 8.8 in my Racecar that makes over 1,250HP. After 2 seasons, the ring and pinion still like like new. Bearings, like new. And...it has a Aluminum rear cover just like the OP.
Weird.

There is nothing fancy inside a factory 8.8 diff cover
The ones Banks makes are just better for high speed and anti foaming
12 bolt Chev coverplates DO have a ridge in them for oil control (only one I know of like that)

Do any modern rear diff fluids come with friction modifier in them so you don't have to add it?

Some of them say they already have it in there like Amsoil. If you go back with a conventional oil then you definitely should use some additive.

If you run a synthetic that’s says it has it then put about 4 oz less than full into the diff and drive it around in a parking lot doing figure 8’s. If it makes noise then add it. If not you are good to go.

The more additive you put in the more the clutches will slip so keep that in mind.

Some folks add an extra clutch (I did) and even move up to the F150 “Z” spring (I did) and that really makes the clutches grip.

All I was trying to say was do your homework.... This article surprised me as I thought all the ring gear did was dip in the oil and fling it around.... No big deal... Just trying to enlighten all with some info I saw....

My car sat for years and I'm just now getting it back on the road. I just went through the hell of replacing my parking brake cables and now I need to install new drum brakes. I'm going to do the diff fluid while it's in the air on jack stands and was just curious. I remember changing it years ago but don't remember adding in friction modifier.

Specs

Does my rear end get hot??? Just want to know because its up on blocks right now for one week