Front suspension and Dana 30 axle seal

[lbuch40]

I will be installing a new WH suspension kit on my ‘69. I also need to replace the front axle seals in the Dana 30.
Is there any advantage to replacing the seals at the same time as I change out the coil springs? As in, duplicative work steps needed for both? Or making it easier or more convenient to do both at the same time?

 

[DirtDonk]

I can’t see any.
Other than maybe the fact that you’re “already in the area” with tools handy.
But you’re not removing anything that needs to be done for the seal.
You’re really only changing coil springs and shocks (and perhaps C-bushings?) but none of that requires disassembling the brakes and hubs.
The closest you come to that is taking the wheel and tire off just to get easier access to working on the coil.

 

[DirtDonk]

Does your 30 have the outer tube seals? I can’t remember if they were all that way, or some came with the inner axle seals down in the differential, like the 44 did.
Either way though, no, you can consider it a separate job.

 

[lbuch40]

Thank you . Obviously I have never tackled either of these jobs. I had the C bushings replaced at an alignment shop about 5 years ago. So I didn’t figure I need new ones with just a 1.5” lift on the new suspension? (Even though I think they come with the kit)
The exploded view of the Dana 30 in my Chilton’s only shows the one seal. I guess I will find out!

 

[Teal68]

Does your 30 have the outer tube seals? I can’t remember if they were all that way, or some came with the inner axle seals down in the differential, like the 44 did.
Either way though, no, you can consider it a separate job.

I think all Dana 30's have inner and outer seals. At least that has been my experience.

As far as doing it while doing the lift, the only repetitive work would be removing the tire/wheel. If you need to also do the inner seal keep in mind you will need to get the cover off and remove the ring gear, carrier, and bearings too. If the outer seal is leaking it means the inner seal is leaking too.

 

[lbuch40]

All I know for sure is that it’s leaking out by the hub.

 

[gnpenning]

When you say leaking by the hub, are you talking about the locking hub. If so then it going to be wheel bearing grease in that area. If not and by the inner C you will need to disassemble to pull the axle

 

[DirtDonk]

Thank you . Obviously I have never tackled either of these jobs. I had the C bushings replaced at an alignment shop about 5 years ago. So I didn’t figure I need new ones with just a 1.5” lift on the new suspension? (Even though I think they come with the kit)

Then tackle it whenever you’re ready. Either now or later. Leaks are a pain!

Unless you still have the alignment read out from when you change the bushings years ago, I would take the extra effort and cost right now to go get a current reading of your caster.
You don’t absolutely need to install the bushings that come with the kit. And they may very well be the same bushings you had previously. But it would be nice to know what your caster is, so you can guesstimate what it will be after the lift.
That will help you decide whether to install new bushings at this point or not

And you haven’t mentioned anything, so I assumed that, up until now at least, it drove pretty well?

The exploded view of the Dana 30 in my Chilton’s only shows the one seal. I guess I will find out!

Probably because, if I remember, they did not all have an outer seal at the tube end. Even today, aftermarket seals are only available for Jeep axles. Not sure if they'd even fit the Bronco version of the 30.
Does it show the inner seal? Got a pic of the page you're looking at that you can upload? Sorry, not near any of my books right now.
Probably member Oldtimer has the factory info on that.

Paul

 

[Teal68]

Here's what I have noted for inner axle seals:
Inner 471766
Outer 480570

Edited to clarify location.

 

[Oldtimer]

From 68 FORD shop manual.
See PDF for hi resolution.

 

[lbuch40]

Then tackle it whenever you’re ready. Either now or later. Leaks are a pain!

Unless you still have the alignment read out from when you change the bushings years ago, I would take the extra effort and cost right now to go get a current reading of your caster.
You don’t absolutely need to install the bushings that come with the kit. And they may very well be the same bushings you had previously. But it would be nice to know what your caster is, so you can guesstimate what it will be after the lift.
That will help you decide whether to install new bushings at this point or not

And you haven’t mentioned anything, so I assumed that, up until now at least, it drove pretty well?


Probably because, if I remember, they did not all have an outer seal at the tube end. Even today, aftermarket seals are only available for Jeep axles. Not sure if they'd even fit the Bronco version of the 30.
Does it show the inner seal? Got a pic of the page you're looking at that you can upload? Sorry, not near any of my books right now.
Probably member Oldtimer has the factory info on that.

Paul

Here’s the page. So when I looked again, whaddya know…. I see two seals. I guess my wife is right about my vision.

 

[lbuch40]

Then tackle it whenever you’re ready. Either now or later. Leaks are a pain!

Unless you still have the alignment read out from when you change the bushings years ago, I would take the extra effort and cost right now to go get a current reading of your caster.
You don’t absolutely need to install the bushings that come with the kit. And they may very well be the same bushings you had previously. But it would be nice to know what your caster is, so you can guesstimate what it will be after the lift.
That will help you decide whether to install new bushings at this point or not

And you haven’t mentioned anything, so I assumed that, up until now at least, it drove pretty well?


Probably because, if I remember, they did not all have an outer seal at the tube end. Even today, aftermarket seals are only available for Jeep axles. Not sure if they'd even fit the Bronco version of the 30.
Does it show the inner seal? Got a pic of the page you're looking at that you can upload? Sorry, not near any of my books right now.
Probably member Oldtimer has the factory info on that.

Paul

Sorry for two different subjects going here, but with regards to the existing castor, it drives great down the road 60-70 mph no problem.
Referencing the Chilton’s again, it says caster cannot be adjusted. So I am just guessing here that when a significant lift kit is installed, the caster is adjusted by installing corresponding C bushings that change the caster according to the amount of lift ?

 

[DirtDonk]

That is correct. It’s not the “correct“ way to adjust castor on a Bronco. But it is typically the easiest way. And the only way most people can do it.
Tilting the axle back like that corrects caster angle to compensate for a lift, or lack of caster from the factory. But it also compromises the front pinion/U-joint angle.

The only real “correct“ way to tweak the caster and not hurt the U joint, is to cut-n-turn the outer steering yoke (kingpin yoke?) instead.
Keeping a minimal C-bushing angle and changing the caster angle to whatever you like. Then re-welding the yoke when you achieve your desired angle.

 

[jamesroney]

@DirtDonk So before we get into the relative merits of the "cut and turn" on the Dana 30...I will point out that I didn't, and won't cut a 30.
No one who is serious about using 4WD would run a Dana 30. So no one would ever need to lift a Bronco with a Dana 30. There will be some who argue this, and that's fine. No one who ever lifted and used their Bronco off road would not have been better served with the 71-77 Dana 44.

Watch out for seal number ID on the Ford MPC. @Oldtimer knows this, but some people might not. The root part number for an oil seal is "3254" So every Ford oil seal will end up with a -3254 oil seal. You need the Ford DeCoder (MPC) in order to complete the puzzle. So the D30 Inner Axle Seal is the C6TZ-3254-D, which is the National 471766 and it's 2 inch OD and 1.25 ID. The D30 Outer Axle Seal is the C6TZ-3254-B, which is the 480570 and is 2 inch OD with a 1-3/8 ID. Now, strangely, the C6TZ-3254-C is the D44 inner axle seal with 2 inch OD with and has the integral tube guide.

Also watch out for RockAuto and their seal listings. They reference the VIN cut-over of K20000 in the 66-70 listings....but K20000 is the November, 1970 Dana 44 serial number cut over for the 71 Bronco.

I always worry about people with 1969 Broncos and Dana 30's. Because of the 30/44 hybrid axle, and because the inner axle seal for the hybrid 44 is the oddball. I ran into another one of those last year.

 

[Teal68]

I'm going to go back and edit my post. The numbers I listed are for the inner and outer seals in the axle tube for the inner axle.

 

[Teal68]

All I know for sure is that it’s leaking out by the hub.

If it is leaking at the lock out hub none of the seals discussed will help. If that's the case it's just bearing grease getting by a bad o-ring on the hub.

 

[lbuch40]

When you say leaking by the hub, are you talking about the locking hub. If so then it going to be wheel bearing grease in that area. If not and by the inner C you will need to disassemble to pull the axle

Maybe I didn’t use the correct terminology.
But the attached photo shows where it is leaking.

 

[Broncobowsher]

Inner axle seal. Leaks oil down the axle tube and is dripping off the bottom king pin.
That is the pull both axle shafts, and that means all the wheel bearings and brakes to do so. Pull the front cover and pull the diff with ring gear. The only parts that can stay are the pinion and knuckles. Beyond that you are stripping the axle housing.

All that work, you better replace both.

Since you pulled all the wheel bearings and the spindles off, those seals as well. Repack the wheel bearings, clean the lockouts (don't over-lube them, they jam with too much grease)
Hope all the sealing surfaces are in good shape, not grooved or pitted bad.

You are just about completely rebuilding the front axle just to change those axle seals.

 

[lbuch40]

Thanks for the confirmation and advice. That is pretty much what I was expecting. Sounds like a big job.

 

[DirtDonk]

And you get to find out if it’s just leaking because the seals are worn out, or the axle shafts are grooved so much that they can’t seal anymore.
Meaning, new seals along with, new axle shafts or Speedi/Redi sleeves.

And, if the kingpin bushings/bearings are worn out, you get to replace those too.
Which are kind of finicky with 30’s sometimes.

But at least you shouldn’t have to re-reset the gear mesh!