So I finally put the rear brakes back together after replacing the rear axle seals. Then I took out the fill plug out to refill the 8" rear end, which I assumed would be empty, or almost. When I took out the axles no oil came out, but I thought that was because most of it had leaked out all over the road and the brakes.
When I opened the fill plug on the drivers side of the pumpkin it started pouring out as though it was over filled. I guess it could be due to the back of the car being up in the air with the front on the ground, but shouldn't it be empty? I was looking forward to putting all new gear oil in the rear end. What's up?

 

The plug is too low for the oil to pour out the axle tubes. With the front of the car a foot or more higher than the rear, though, the oil level could easily be 1/8-1/4" higher than the bottom of the hole.

 

So I was thinking of pumping new fluid in and try to at least displace some of the old oil with new clean oil. I think I'm due for a pinion seal seal soon as well, but I'm gonna take it somewhere to do that. As long as the oil is at the level of the fill plug it's ok right? The oil coming out looks fairly clean, but not new. The rear end was swapped sometime in the past, so at least it's not 42 years old.

 

Why? You can do that yourself in a couple hours, even if you stop for coffee. (I know a trick)

 

I read something about torqing the crush collar correctly or something like that. It seemed like the nut had to be tightened just right or it would be bad. I guess I'll research some more. It's a slow occassional drip from the U joint at this point, but as I drive the car more I'm guessing it will get worse.
Is it really that easy? I'm a novice!

 

This is one place I depart from the FSM. A friend has a big speed shop and he taught me a trick for replacing the pinion seal.

•Disconnect the driveshaft from the pinion flange.
•Mark the pinion flange for position.
•Hold the pinion flange in place with a large wrench, or put a pin through one of the bolt holes to immobilize it.
•Remove the pinion flange nut.
•Remove the pinion flange.
•Clean the threads on the pinion shaft.
•Remove the seal.
•Install the new seal.
•Install the pinion flange.
•Install a new pinion flange nut.
•Torque the nut to 125 foot-pounds.
•Install the drive shaft.

This will work for any Ford rear, because amazingly, they used this same nut on all their rears, the 7", 8", 9", 7.5", and 8.8".

It does not further compress the "crush collar", because that is installed at 175 foot-pounds.

 

It's that 175 foot pounds that gets me in trouble. I dont have a torque wrench that will go that high. Mine only goes to 140. I don't want to torque it wrong and ruin the rear, but I also don't see needing a new torque wrench just for this. What else gets that much that I would need a bigger torque wrench? Maybe I do need a new tool for future use.

 

What 2+2 is saying is you only need a torque wrench that goes to 125.
Don't go over 125 or you will crush the crush sleve and change the pinion bearing preload.

Having said that, it seems like a risky venture to me because you are just assuming the preload is correct.
If it is too tight or loose you will cause premature bearing failure.

Edit:I don't usually disagree with 'experience' and I don't always do things by the book.
I could see how it would be close, but depends on amount of wear and if you require dead nuts on or not.

 

Just my two cents but I agree with 2+2 and have been doing it that way for years. Most folks will tell you that the crush sleeve has to be replaced when doing the pinion seal but it doesn't. The crush sleeve needs to be replaced when replacing the bearings only not the seal. If the rear end has run for 50,000 miles or so on the sleeve that is in there it should run another 50,000 miles with the same sleeve as long as you don't crush it any more than it is. And actually I don't use a torque wrench I use my 1/2 IR impact. I run the nut down with the impact until the nut seats home and then blast it one time for about 1 second.

Also that 175lb thing is not exact either. When setting bearing preload it is the end play that you need to measure on the pinion assembly that will tell you when preload is correct. If you think you can just torque it to 175 and call it good without checking endplay you stand a good chance of messing up the pinion bearings by running with bearings too loose.

 

BTW the only way to really drain a ford rear is to pull the pumpkin or use suction to pull the old fluid out.