Fluid Change in Ford 9" Diff.

[69rangerman]

So I'm still going through checking and replacing stuff and could not find a drain plug for the diff. Nothing in the manuals about how to do a fluid change either. Do I have to remove the drive shaft, and the front cover to change fluid? I appreciate any how to's and warnings for this.

Thanks,
Tom
69 Ranger/302/fmx/9" rear/LWB

[Maxum96]

You'll have to pull the axles and remove the 3rd member to drain the oil on a 9" rearend.

[68F250]

Or you can use a suction pump to pull the old lube out the fill hole.

[Big D's 69]

Or you can use a suction pump to pull the old lube out the fill hole.

That sounds like the best plan. Might take a little patience but a whole lot easier.

[67heavystepside]

go and buy a mighty vac , it is a vacume container that you pump up and suck away. it holds like 3 gallons, it comes with like 4 lines. you can even bleed brakes with the right attachment. works with all fluids. they also make one that is air powered(that is the one that i have, and love it)

[69rangerman]

I was going to ask about pumping it out...was thinking someone would bring up the warning about metallic residue left in case etc. Good to know it can be pumped out.

By the way, I've never changed diff fluid before - should it be muddy brown? When I checked the level that's what dribbled out.

Thanks for the help.

[390Nut]

Only when the gear oils never been changed in the life of the truck.

A lot of people swear by not using a gasket when reassembling, and instead just clean the surfaces really well and use silicone (blue or ultrablack Permatex will work).

If you do, make sure you let it sit overnight before adding gear oil back in, or it will never seal.

[69rangerman]

That's what I figured...OK, so I pump out the mud water, replace with new fluid. Assuming there is a seal/gasket there ancient as it is do I need to pull the axles and replace it? Still working on mechanic chops-not sure I'm ready for that yet.
Thanks,
Tom in FL.

[FORDification]

Yes, if you decide to replace the pumpkin gasket, you'll have to slide the axles out and the completely remove the pumpkin. If this was me and was the first time I'd done anything to the rearend of this truck, I think I'd want to remove the pumpkin anyway. That way I could not only replace the gasket, and get all the old fluid out (including the stuff that a pump might not be able to reach), but I could also eyeball the pumpkin internals and make sure everything looks OK.

My

[69rangerman]

Thanks Keith,
I read up on the axle pull last night. Just to clarify- the axle housing itself can stay in, I'm just removing the drive shaft side cover to let the oil drain, replace gasket, and check out internals. Am I looking for missing teeth, rounded off teeth, etc.??

Sorry for the ignorance - I've got some book learnin but not much hands on experience (that's changing rapidly).

Tom

[flyboy2610]

Thanks Keith,
I read up on the axle pull last night. Just to clarify- the axle housing itself can stay in, I'm just removing the drive shaft side cover to let the oil drain, replace gasket, and check out internals. Am I looking for missing teeth, rounded off teeth, etc.??

That's pretty much it. Look for extreme wear on the gears

Sorry for the ignorance - I've got some book learnin but not much hands on experience (that's changing rapidly).

Tom

That's how most of us started out. And we're still learning.

[69rangerman]

Thanks guys,
The desk jockey is becoming a wrench monkey-feels good.

[Big D's 69]

Nothing like hands on experience. There isn't really anything that can't be figured out over the site or an assembly manual.