OK well i was going to help my dad today with his truck to repair his axle on his f250 super duty and i started to hear a wineing sound coming from the rear of my truck. when i got to my fathers house i decided i would got check under my truck and saw that the gas tank and the bottom of my trucks bed was full of gear oil. now my question is would it be a pain in the *** to change the front seal of the diff and should i change anything else while i have the front of it apart?

BTW the axle work to my dad truck is the gear he wants to change out.

 

Changing the pinion seal is a piece of cake, but if it's is leaking and the rear end is making noise, there's an excellent chance your pinion bearing is bad. I would check that, the gears, and the carrier bearings to make sure little bits of metal didn't damage other stuff.

 

ok thanks for the heads up

 

It might be low on fluid. When was the last time it was changed? Lets hope its not to low. Pinion seals are easy to change. The thing most people do is over tighten the pinion nut and further mess it up. We owned a 95 grand cherokee that started to howl at about 130k. Changed the fluid and it helped a little. We finally took it off the road at 216k same howling rear end. I then took it apart and welded the spiders and used it for a woods beater and it held up just fine.

 

i dont think its ever been changed i bought this truck 3 years ago. and it is at 132,000 miles.

 

Would have to agree with TomA. Seal is easy to replace,but need to take cover off and check everything over real good. Looking for chips,cracks,broken parts. Move it around while it is apart listen for any unusual noises.

 

OK so just a quick question on changing the seal.

I need to mark and count the turns of the nut, and replace the nut with the same amount of turns as to not mess up the crush bearing, correct?

And I was told if those seals start to leak it is usually cause by another reason, so to investigate the reason, usually pressure in the rear-end.

Is all this sounding right?

Thanks,
Medic

Just bought a 2001 Dakota crew cab with 130k km

 

well as for changing the seal all i did was count the amount of threads sticking out of the nut and measure from the backing plate out to see how much thread was exposed in order to make sure everything was right. As for checking what cause it i dont know i just changed the seal and left the rest alone.

 

You are supposed to measure the force it takes to turn the pinion by using an in-lb gauge. Thats what you want when putting it back together.

 

In actual practice, I've never seen a case where properly torquing the pinion nut after replacing the seal was enough to further compress the crush sleeve and change the bearing preload. If you've ever set up a differential, you know it takes a ton of torque to crush one of those things.

And it's impossible to accurately measure the rotating torque on the pinion without removing the carrier.