rear pinion seal is leaking not bad but i dont want it to get worse and my diff plug is leaking question is my diff cover plug alwats rubber plug it aint a screw on plug

 

8.25 rears all have a rubber plug rather than the screw in type. The pinion seal is pretty easy to replace. As long as you've got over 150psi of air, you can use an air gun on the pinion nut and it'll come right off, giving you easy access to the seal itself once you pull the pinion out.

 

yeah i never realized how easy it is to do a pinion seal till i did my front one, i had people tell me its really hard, but i was done in little over an hour

 

Yeah, everyone had always told me it was a pain, but it was actually really easy. Only took me about 40 minutes to do both front and rear seals.
If the drain plug is leaking, just find a new one ( $13 at AdvanceAuto) or pick one up from the JY for cheap.

 

I've got 625ft/lb wrench,is there a puller required for the front pinion seal? I just changed to synth.lube in the diff.am I gonna lose it when I pull the seal?

 

no puller needed. Just take the pinion nut off, and the pinon should come right out. Then pop out the old seal with a screwdriver. As long as you didn't over fill the diff you shouldn't lose any fluid.

 

I don't get how the seal leaks but when you pull it out no fluid comes will come out.

 

When the vehicle isn't moving, the gear oil settles in the diff. If it's not overfilled, the oil settles below the seal lip, thereby, not leaking out when you remove the seal. However, when you're moving, the gears in the diff are constantly churning the oil, bringing up past the level of the seal, thereby allowing it to get to the worn seal and leak out.

 

Why certainly!

 

where do you add fluid to the differentials at? What type, and how do you know how much?

 

You add it to the fill plug on the diff. cover and when filling it fill it to the when you can feel fluid if you put your finger in the hole

 

I realize this thread is old but thought I'd ask my question here rather than starting another thread about the same thing.

I've read to mark the nut and pinion, count the threads sticking out of the pinion nut before removal. Is this the correct/best way to remove the pinion nut?

 

It's better than nothing but just a stop gap anyway. If the seal is leaking chances are the worn bearings made it that way.

 

Depends on axle.

The earlier Jeeps with a high pinion D30 have a solid spacer and shims to set pinion bearing preload. On these any reasonable torque over 125 ft-lb is fine.

On low pinion D30's and rear axles like the D35 and 8.25 there is a crush sleeve to set pinion preload. proper procedure is to remove the brakes and measure rolling torque before loosening the pinion nut. Then tighten back up to achieve the same rolling torque. Measuring rolling torque requires a beam type torque wrench or Torqometer type. Click type will NOT work.

The real goal is to keep the pinion bearing preload the same. Since the crush sleeve is designed to crush and increase the preload, if you tighten too much you get to take the whole differential apart to redo the crush sleeve. also note that once end play is eliminated, as little as .025 thickness change can change the preload 8 in-lb and spec range on used bearings is usually around 10 in-lb. In other words, once you get close adjustments would be 1/8 or 1/4 turns if your cheater bar:

 

Buying a aftermarket cover with screw in plug and leak will never return.