notice rear differential leaking

[kmartin]

Today I have noticed some drippings on the garage floor. Upon through inspection, it looked like the rear differential is leaking from where the drive shaft goes into it. So what are my options?

 

[ElectronFlow]

 

[koda2000]

Pinion seal. Around $6-$8.

I had this happen on our 2000 Mountaineer recently. I removed the driveshaft from the rear end, removed the pinion nut and yoke, replaced the seal and reinstalled the yoke and pinion nut, stopped turning the nut when I couldn't move it any more.

This is a bit of a cheat because I did not replace the crush sleeve, but it takes 200 foot pounds to crush the sleeve and that's hard to achieve laying under the truck, so once the nut stops turning it's back to it's original sleeve torque.

I did this last spring and it hasn't leaked a drop since. Worked for me. Your results may vary.

If afterwards your diff makes noise on deceleration the nut isn't tight enough (ask me how I learned this).,

 

[410Fortune]

first check your vent tube make sure its not plugged

The rear diff is a housing with gear lube in it. When you drive and the lube heats up it expands, the air on top of it must be able to escape. If the vent tube is plugged up then it cannot breathe and it will force fluid out other holes/through the axle or pinion seals.........

 

[kmartin]

first check your vent tube make sure its not plugged

The rear diff is a housing with gear lube in it. When you drive and the lube heats up it expands, the air on top of it must be able to escape. If the vent tube is plugged up then it cannot breathe and it will force fluid out other holes/through the axle or pinion seals.........

Once it pushed through the seals, well then your seals will need to be replaced.

 

[koda2000]

You can check your vent tube (damn mud wasp's clog any hole they find) but your pinion seal probably needs to be replaced. Mine started leaking at about 235-240K. It's a relatively easy job as long as you have the tools needed. Begin by seeing if you fill plug will come out.

Ramps, or a floor jack, and safety stands
Socket for pinion nut (1/2 drive) I don't call the size (metric or SAE works)
Long 1/2" breaker bar
A 1/2" pneumatic or electric impact gun is helpful but not a must
12 MM 12-point wrench or socket for drive shaft bolts
A piece of pipe to add leverage
A seal puller
Sealant for around the outside of the seal
Some grease to pack the back of the seal and lube the outside of the yoke
A hammer and a piece of 2x4 to install new seal
Blue lock tight for the drive shaft bolts

Gear oil to refill the diff (I used Walmart 80W90) Full synthetic 75w140 is recommended, but expensive and I didn't know whether the repair would work and the truck is 20 years old with 265K+ miles so $20 vs $65. If you drain the rear diff you'll need about 3 qts of oil. I had to do this as my fill plug was frozen stuck. The only way I knew how much oil to put in through VSS hole was to remove the rear cover and completely drain the dif.

If it still leaks after replacing the seal you have pinion bearing issues. Big $ repair.

 

[ElectronFlow]

 

[kmartin]

Your luck. Mine as only 105,000 miles. I think I will get a mechanic to work on it. Too much for me to handle.

 

[donalds]

Socket for pinion nut (1/2 drive) I don't call the size (metric or SAE works)

1 1/8

 

[donalds]

Once it pushed through the seals, well then your seals will need to be replaced.

it really depends on where the seal leaking from
I would check the vent if it's clogged then remove and clean it up
Clean off all the leaked oil off the diff housing
And see if it leaks
It is a pain in the butt job to replace the seal so if you can avoid it do so at all costs.
iMO