[cmonson]

OK, I have a bad rear axle seal. I see I need to take the axle out, then take it to a shop so they can press on a new bearing/retainer.

My question is, is there an inner seal???

How does the diff fluid stay within the diff assembly? If there is NOT an inner seal, doesn't the entire axle tube fill up with diff fluid? I also see the axle tubes sit above the oil fill point on the diff.

I have a dana 35 on a 2000 Grand Cherokee.

I am really confused as all of the exploded views I can find do not show an inner seal, and without it I woudl think the entire axle shaft would be completely full of fluid. But it is even more confusing as the axle tubes sit above the oil fill hole...

Someone help me with this inner seal question...

thank you,

cm

[fast_man58]

the oil is allowed to go down the tubes and lubricate the bearings. when the gears are moving, all sorts of oil is being splashed and moved around.

to answer your question, there is no inner axle seal.

[cmonson]

It just seems odd that the assembly would count on oil getting all of the way down there to lube the races.

Even more so that the axle tubes are up pretty high on the diff.

[AgitatedPancake]

Thats the way it works

[cmonson]

sounds good.

looks like you don' even have to drain the rear diff to change out the outer seals / bearings.

anyone confirm?

[AgitatedPancake]

no you dont, though I always raise up that side of the axle a little to make sure it doesnt start leakin out.

[StrokedWJ]

FYI, theres a pretty decent write-up on jeepslimited.com by a guy named Cebby.

[cloiselle]

Originally Posted by AgitatedPancake

Thats the way it works

it's an aweful design, it allows bearings to dry and heat up as well as lack of optimum lubrication of the differential gears, go feel your rear diff any time after you cruise around and see how hot it is if it's a d44a especially . this also alows slop to occur with the bearings , further increasing the rate at which they wear out . the jeep engineers didnt think it was a bad idea though

[ArloGuthroJeep]

Dana made the axle - not Jeep

[indept]

Originally Posted by cloiselle

it's an aweful design, it allows bearings to dry and heat up as well as lack of optimum lubrication of the differential gears, go feel your rear diff any time after you cruise around and see how hot it is if it's a d44a especially . this also alows slop to occur with the bearings , further increasing the rate at which they wear out . the jeep engineers didnt think it was a bad idea though

That's the way rears have been since the dinosaurs roamed the earth. As long as the seals aren't leaking & the lube is at the right level they will be ok. If the lube is correct there will be gear lube the entire length of the rear (when on level ground)

[xJoshxx]

Originally Posted by ArloGuthroJeep

Dana made the axle - not Jeep

Tis why we call it a dana 35 and not a Jeep 35.

[ratmonkey]

Anytime you spin something at the kind of rpms an axle sees you'll get it up past 100 or better without active cooling or large heat sinks.

Originally Posted by cloiselle

it's an aweful design, it allows bearings to dry and heat up as well as lack of optimum lubrication of the differential gears, go feel your rear diff any time after you cruise around and see how hot it is if it's a d44a especially . this also alows slop to occur with the bearings , further increasing the rate at which they wear out . the jeep engineers didnt think it was a bad idea though

[ArloGuthroJeep]

I can't believe the engine personally...sometimes that thing reaches 210deg Don't even get me started about the exhaust

[tamnalan]

Originally Posted by indept

That's the way rears have been since the dinosaurs roamed the earth... :

Not quite true - my '43 Willys MB has inner differential seals (made originally of leather!) - the hub bearings are greased -- not lubed by diff. oil.

[captinmrgan]

Large semi trucks have a similar axel set up, with the bearings being lubed by gear oil from the diff and they go hundreds of thousands of miles without problems.