99 XJ front diff Pinion seal

Can I change this out by hand..seems pretty straightforward.Pull the front shaft and the yoke...do I need a Impact gun or will a Breaker bar work?The seal looks wet and it's only like 5 bucks to replace.

Breaker bar will work but it is a torque of roughly 225 ft-lbs and they put thread locker on them. I had to brace the breaker bar against the ground and move the vehicle (can't recall if it was forward or reverse) to get the nut to budge. Sounded like hell but it finally came off. Pulled the seal, put in the new one. Tightened to 225 ft-lbs (ouch) and was done.

Crap...that sounds like a bitch.How was the seal
to pull?It looked like a standard pressed seal...I've done front hubs with a breaker bar and a huge pipe for leaverage

If you can get you hands on an air impact, it's a 10 min job. doing it without could ruin your whole day.

pipe wrench fits the yoke nicely.

wedge big pipe wrench against the ground.
use large breaker bar to get the nut off.

Make a witness mark on the nut and the pinion shaft so you can get them put back exactly how they came off. It's the best you can do without dropping the carrier and setting the preload properly with an inch wrench.

BostonIrish said:

Crap...that sounds like a bitch.How was the seal
to pull?

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The seal is simple - it pulls right out.

BostonIrish said:

Can I change this out by hand..seems pretty straightforward.Pull the front shaft and the yoke...do I need a Impact gun or will a Breaker bar work?The seal looks wet and it's only like 5 bucks to replace.

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D30 Pinion Seal Replacement
Here’s the right way to do this so you don’t end up with too much bearing preload that will cause excessive bearing/race wear:

Block the rear wheels.
Raise the front end high and use good jack stands.
Remove the front wheels/rotors/calipers
Mark the drive shaft and yoke so you can put it back the same way
Remove the drive shaft
Rotate the yoke 3-4 times
Measure the amount of force needed to rotate it by using an inch pound torque wrench
Write down the amount
I use an impact to remove the pinion nut and washer
Remove the old seal with a seal remover tool or a slide hammer with a screw end
I clean the spines on the pinion and in the yoke and lube them with wheel bearing grease
I coat the new seal lip with wheel bearing grease
I use a light coating of black RTV on the metal lip (probably not necessary)
Install the new seal carefully (you can easily damage these during the install)
Install the yoke and washer
I tap the yoke lightly with a small deadblow hammer to seat it on the shaft
Install a “new” nut and washer on the pinion gear
Tighten the nut just enough to take out all the end play of the pinion gear
Tighten the nut to 160ft/lbs.
Rotate the yoke/pinion gear with your inch-pound torque wrench, check the reading
If the amount is lower, tighten the nut in 5 inch pound increments till you get there plus 5in/lbs.
Put it all back together

If all this seems a bit much, you can do like some guys and just run the pinion nut down to a point where all of the end play is gone which is usually between 160-200ft/lbs. and hope there isn’t too much bearing preload. Personally I would never do it this way on newer gears or a low mileage vehicle.

My advice, for what it’s worth, is if it’s just seeping a little is to leave it alone and watch it rather than risk the possibility of wrecking your pinion bearings/races.

I hope you torqued your “new” hub assembly axle nut to 175tf/lbs. Again, preload is very important.

From what I recall, the HP D30 does not have a crush sleeve - the preload is controlled by shims. Therefor, torque on the nut does not control the preload - the shims do. That means you don't need to measure the rotation force with an in-lbf wrench. Just tighten the nut to spec.

Edit: from what I can find it is only LP D30 axles that use the crush sleeve. HP is shims.

the_weirdo said:

Edit: from what I can find it is only LP D30 axles that use the crush sleeve. HP is shims.

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You are correct, HP uses shims and the LP uses a crush sleeve.
This was confirmed from a XJ FSM.

Yep, just recently put in a set of gears in my HP 30 and I can confirm they use shims

OK guys, do what you want, but what I posted (mostly from memory) is close to what my '97 FSM says to do on the high pinion D30 (181 FBI) with shims.

In looking over what I posted I see that I made an error.

Near the bottom it read: "If the amount is lower, tighten the nut in 5 inch pound increments till you get there plus 5in/lbs."

I should have said: If the amount is lower, tighten the nut in 5-foot pound increments till you get to the proper rotating torque plus 5in/lbs.

Sorry for the misstep. I guess I can't edit the original post at this point.

Here's a direct quote from the FSM that's in big bold font: CAUTION: Do not exceed the minimum tightening torque when installing the pinion yoke retaining nut at this point. Damage to the pinion bearings may result.

My thought is even though the pinion gear uses shims the amount of torque is critical, because if an increase in torque changes the rotational force that means the bearings are getting tighter with an increase in torque on the pinion nut.

If there's someone out there with professional credentials that can set me straight, I'd appreciate it, because doing it "by the book" is a lot more work.

Weebur - on a HP D30 for a fresh install you need to do it "by the book" and check the pinion rotating torque and add shims/remove shims as needed to get the correct preload. For a seal replacement on the HP D30 where the pinion torque has already been set when the gears were setup, you only need to tighten the nut to torque.

The LP D30 is another story because it has the crush sleeve.

the_weirdo said:

Weebur - on a HP D30 for a fresh install you need to do it "by the book" and check the pinion rotating torque and add shims/remove shims as needed to get the correct preload. For a seal replacement on the HP D30 where the pinion torque has already been set when the gears were setup, you only need to tighten the nut to torque.

The LP D30 is another story because it has the crush sleeve.

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I think I just saw that dead horse open his eyes...:laugh:

Hopefully I'll end this by saying that the info I put out was from the subsection "Replacing the Pinion Gear Seal" (or something similar) and they mention a difference in settings with existing bearings or new ones.

I have done this job by just running the nut down to where all the end play was gone and adding a little for good measure and the sky didn't fall or the pinion bearing police didn't drag me from my Jeep and beat the crap out of me...I'm just sayin'.

I understand that you are quoting pages 3-26 thru 3-30 of the XJ FSM manual (1999 FSM manual; same for the 2000 FSM which I own both of).

However, it also states:

"Never loosen pinion gear nut to
decrease pinion gear bearing rotating torque and
never exceed specified preload torque. If preload
torque is exceeded, a new collapsible spacer must
be installed. The torque sequence will then have to
be repeated."

which is wrong for a HPD30 which was available in 1999. There is not collapsible spacer on a HP D30, only a LP D30 (yet another advantage to the HP). Please understand that the manual is not always correct (even the FSM).

Putting out proper info is not "beating a dead horse".:kissyou:

the_weirdo said:

I understand that you are quoting pages 3-26 thru 3-30 of the XJ FSM manual (1999 FSM manual; same for the 2000 FSM which I own both of).

However, it also states:

"Never loosen pinion gear nut to
decrease pinion gear bearing rotating torque and
never exceed specified preload torque. If preload
torque is exceeded, a new collapsible spacer must
be installed. The torque sequence will then have to
be repeated."

which is wrong for a HPD30 which was available in 1999. There is not collapsible spacer on a HP D30, only a LP D30 (yet another advantage to the HP). Please understand that the manual is not always correct (even the FSM).

Putting out proper info is not "beating a dead horse".:kissyou:

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I understand and appreciate your input, my comment about the dead horse was just my attempt at a little levity, so back at ya :kissyou:

What I should have said in my original post besides, "I don't know nuttin, and I can prove it!", is something similar to: this is what my '97 XJ FSM says about the high pinion D30 axle, this may not apply to your '99 XJ.

My FSM states in the beginning of the section that the pinion gear is placed above the centerline of the ring gear and nothing in the entire chapter about collapsible spacers. However, there are illustrations in that very section that are clearly low pinion differentials (your point made). I'm familiar with crush sleeves as I rebuilt my D35. So I guess the LP D30 wasn't available in '97 but was later on.

Also, nowhere in my manual does it say to just run the nut down to 200 or even 225ft/lbs. as some have suggested. If I get a chance I'll see if I can get a tech at a local dealer to talk to me about this, and if I'm wrong I'll dig up this thread and post what he said.

The FSM isn't always right. When changing the seal on an HP D30, just torque the nut to 160 ft lbs. No checking preload or tightening the nut in 5 ft lbs increments.

Talyn said:

The FSM isn't always right. When changing the seal on an HP D30, just torque the nut to 160 ft lbs. No checking preload or tightening the nut in 5 ft lbs increments.

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Yeah, that's pretty much what I did the last time (new seal developed a tear). I can live with 160ft/lbs. but not 200-225 on a new nut, but that's just me. Thanks.