Hey guys i need you opinion on this ford 9inch rearend.

[2010Iron883]

Hi guys im new here so hello everyone. I just got this old 78 f150 ranger 4x4 with a 351m. It has the 9in rearend with no pan. Has anyone taken there s apart and serviced it then put it all back and done more harm than good. Im just concerned about pulling it apart since i dont know if it has ever been apart. You know how some things are that havnt ever been disassembled. Just shoot me your opinions. Im having no troubles with it but i do want to get some fresh grease in it. Thanks everybody

 

[LEB Ben]

How in depth are you planning on servicing it? If you just wanna swap fluids, the easiest thing to do is to grab one of those $10 hand held pumps, get the suction hose down the inspection holes as deep as you can, and start pumping it out. Should get 90-95% of all the fluid. IYou should also be able to do it by loosening/removing all but the top couple of bolts and letting the fluid drain.


Beyond that, you're gonna have to pull the axles, drop the drive shaft and pull the 3rd member.

 

[BKW]

If it ain't broke, don't fix it. Just use the method Ben suggested to change the fluid. If you pull it apart, you'll be opening a can of worms.

 

[bucks77ford]

If it ain't broke, don't fix it. Just use the method Ben suggested to change the fluid. If you pull it apart, you'll be opening a can of worms.

I also agree here. But, you shouldn't have too many cans of worms to open if you do take things apart. The 3rd member will come out as one piece and nothing will or should move so going back should just be a simple bolt on and nothing else. Granted, you'll have to replace the gasket and you should replace the axle seals since you will have pulled the axles. Old seals sometimes don't leak until they are manipulated. However, if it works fine I wouldn't mess with it and just replace the fluid.

On a side note, why people have done this I don't know, maybe just for ease of replacing fluid, but I've seen 9 inch rear ends tapped at the bottom and threaded to accept a plug for draining fluid.

 

[Mil1ion]

Yet I have seen the truck lifted so high on one side to allow oil to flow out the axle tube.
I shook my head for weeks after seeing that.

 

[LEB Ben]

On a side note, why people have done this I don't know, maybe just for ease of replacing fluid, but I've seen 9 inch rear ends tapped at the bottom and threaded to accept a plug for draining fluid.

Outside of potential leaks, what's the issue with this? I've been thinking of doing it.

Yet I have seen the truck lifted so high on one side to allow oil to flow out the axle tube.
I shook my head for weeks after seeing that.

HEHE...been guilty of this too, on a buddy's rig though. Honestly, looking back, it was more trouble than actually pulling the 3rd member...and more stupiderer too.

 

[BKW]

I also agree here. But, you shouldn't have too many cans of worms to open if you do take things apart. The 3rd member will come out as one piece and nothing will or should move so going back should just be a simple bolt on and nothing else. Granted, you'll have to replace the gasket and you should replace the axle seals since you will have pulled the axles.

But...if a novice doesn't know how to remove the carrier and messes with the pinion nut, the whole equation changes.

Like I said, if it ain't broke, don't fix it. Newbie owners seem to have an in-grown passion for takin' things apart needlessly, then the inevitable occurs.

 

[speedshifter]

I would say if you think you can remove/install the 3rd member correctly i would go for it. If nothing else you can get a good look at the internals.

 

[Mil1ion]

The only ones that need any attention are the ones that leak and the ones that howl louder than the exhaust

 

[bucks77ford]

Outside of potential leaks, what's the issue with this? I've been thinking of doing it.

Nothing except for potential leaks, but would be a nice way of changing fluid. I was thinking more about it and at first my thought was why risk leaks if you can just suck the fluid out, but after thinking about it, I'm sure it's a great way to see if there are any metal chunks that could fall out. So, really it would be a good idea if done right and no leaks.

 

[Dirky]

I will always pull the pan, or in this case, the 3rd member when changing out diff fluid.

Why?

Because this way, I can properly clean and inspect the gear set and components.

Leaks? It is no harder to seal up than your conventional pan, just a little more heavy and cumbersome. Worth the effort IMO!

 

[73F100Shortbed]

Mine leaks a bit. I just check the fluid every so often. I would recommend just sucking the fluid out.

 

[1985 Ford F-150]

Id just suck it out as well unless youre gonna rebuild the whole axle then id drill a hole and tap it.

 

[2010Iron883]

Im thnking of doing the pump option. You know you guys are just like me in i thought about jacking up one side myself lol!! Have you done the pump thing before? Im just wanting to change fluids i have no issues with the rear end other than i bet it has never had a fluid change

 

[Alvin in AZ]

Have you done the pump thing before?
...i bet it has never had a fluid change

Yes I tried it and no, I couldn't get the hose down inside it far enough
to get it to work. :/ YMMV?

And yes I bet you are right about that fluid change.

Your Ford9inch got Traction Lok?
If so you'll need to add friction modifier to the oil change.
(even Mobil-1 gear oil needs it)

If you pull the differential be careful not to bend the housing, it's not
"spring tempered" steel. BTDT and ended up with a leak I had to fix
by pulling it again.

I put a "microwave" magnet down in the bottom of my housing.

Hmmm... I bet a guy could put an old "hard drive" magnet down in the
bottom of the steering pump housing too. Or maybe just stick it to
the bottom on the outside?

Nutty Boy in AZ

 

[2010Iron883]

I ended up going to southern states and getting the largest syringe they had. I put a tiny hose on the end and ran it down the fill hole. I sucked out 2 and a half quarts but it took about 30 mins

 

[2010Iron883]

I run valvoline 80w145 limited slip gear oil and about a 1/4th a quart of lucas oil stabilizer. it has done very well with that.