help to identify a front differential

[Ironlung1948]

Hello everyone. I have been lurking for sometime on this site after purchasing a 67 ford bronco . I must say this community is quite active and very helpful so I thought I would post my question here .

I began to tear apart from front end for rebuilding and I cannot confirm with certainty what type of front differential I have. I initially thought it was a dana 30 however the cover has only 9 bolts where as the replacement dana 30 covers are all 10 bolts.

Also this truck has not been moved in years . After removing the front cover, the diff had no oil , dry and rusty and the ring and probably pinion are destroyed . I was planning on taking it to a machine shop to have it looked at but do you think a simple ring and pinion rebuilt from toms would be sufficient or does the whole shabang need to be replaced. ie lockers etc. ? ( or is that for rear diff only? )

sorry in advance if im not making any sense. outside of changing a tire i have never tinkered with a vehicle to be honest. The front end took me 3 weeks to remove but im learning!

please see pictures .

thank you

 

[Ironlung1948]

Hello everyone. I have been lurking for sometime on this site after purchasing a 67 ford bronco . I must say this community is quite active and very helpful so I thought I would post my question here .

I began to tear apart from front end for rebuilding and I cannot confirm with certainty what type of front differential I have. I initially thought it was a dana 30 however the cover has only 9 bolts where as the replacement dana 30 covers are all 10 bolts.

Also this truck has not been moved in years . After removing the front cover, the diff had no oil , dry and rusty and the ring and probably pinion are destroyed . I was planning on taking it to a machine shop to have it looked at but do you think a simple ring and pinion rebuilt from toms would be sufficient or does the whole shabang need to be replaced. ie lockers etc. ? ( or is that for rear diff only? )

sorry in advance if im not making any sense. outside of changing a tire i have never tinkered with a vehicle to be honest. The front end took me 3 weeks to remove but im learning!

please see pictures .

thank you

 

[Ironlung1948]

sorry I cant seem to upload photos ? however my cover / diff appears to be identical to the dana 30 however it does not have a bolt at the 6 oclock position

 

[DirtDonk]

No problem Ironlung. It's not you!
The only way to upload directly from your device to the forum threads is to become a contributor for 12 bucks a year. That's the "best" way, but you can also upload some limited images using your "garage" feature in the User CP.
Or if you prefer, and expect to do a lot of pics (we hope!) you can also use another online image hosting site and link the pics to your thread.

Most of us here are biased though, and feel that the best way is to become a contributor.
I like it because it's easier and it keeps the site up and running very smoothly with Jon keeping things up to date, but not too "fancy" like some are.

And welcome to classicbroncos too by the way!

Paul

 

[thegreatjustino]

You need to be a paying member to post photos directly in your post. You can also remote host them and link to them.

Photo instructions here:

http://classicbroncos.com/forums/showthread.php?t=34373


Front axle ID here:

http://broncohio.com/tech/dana30dana44.html

You can also compare the front cover with this image:

 

[DirtDonk]

You can also email an image to someone with the yellow "contributor" beneath their username and we can post it up for you. Would be me in this case, so just let me know if you want to do that.

Usually the difference is between a 30 and a 44 and I thought they had the same 10 bolts.
Here are some images of the two styles on our (Wild Horses) website: https://www.wildhorses4x4.com/category/Bronco_Dana30
Notice the slightly different shape of the two gaskets.

Paul

 

[Ironlung1948]

ah okay. well i just joined ! I signed out and back in and still no option to upload pic . Do i have to create a new thread ? ?:?

 

[DirtDonk]

Also this truck has not been moved in years . After removing the front cover, the diff had no oil , dry and rusty and the ring and probably pinion are destroyed .

Typical after sitting for so long, but with maybe someone putting it away dry, thinking they'd get around to filling it and didn't.

I was planning on taking it to a machine shop to have it looked at but do you think a simple ring and pinion rebuilt from toms would be sufficient or does the whole shabang need to be replaced. ie lockers etc. ? ( or is that for rear diff only? )

Good first step probably, but any shop, honest or not, must tell you that it needs to be replaced. They can't stake their reputation or insurance premiums on old parts being usable. Especially if they do the work in-house. In that case it's going to need all new parts.
It really depends on how bad it is. When we see your pics we might be able to send you in the right direction. Because of how they are, I would be tempted to just put gear lube in it, then drive it around with the hubs locked for awhile. Then drive it around in 4wd with the hubs UNLOCKED for awhile.
Might not do that with the rear end, but the front is perhaps a little less finicky. Especially if you do not four-wheel it much.

sorry in advance if im not making any sense. outside of changing a tire i have never tinkered with a vehicle to be honest. The front end took me 3 weeks to remove but im learning!

Makes total sense. And seems you're in the same boat with many new Bronco owners. Never worked extensively on a vehicle, but a Bronco seemed like a good start.
In many ways they are too. But with so much more to them that meets the eye, you will certainly run into things that will make you pull your hair out and question your sanity.
But you'll get through it, even if it means coming here and asking questions.

Good luck!

Paul

 

[DirtDonk]

ah okay. well i just joined ! I signed out and back in and still no option to upload pic . Do i have to create a new thread ? ?:?

Hey, thanks for becoming a contributor right off the bat!
Nope, you can either add another post to this existing thread with your pics, OR you should be able to go back and click on the "edit" button and then "go advanced" to upload your pics to the prompts.

Give that a shot first to see if it works.

Paul

 

[Ironlung1948]

JK found it !

 

[DirtDonk]

Ok, might have to wait a certain amount of time, or wait for a few more posts then. But you're already up to 5 and I don't think we have any major requirements of that sort.

Go ahead and e-mail me at paulb@wildhorses4x4.com and I'll post 'em up.

Paul

 

[Ironlung1948]

Got it ! thanks for the help

 

[DirtDonk]

Wow, the ultra-rare 9-bolt Dana 30!;D
Haha! Never seen one like that. Maybe at some point a bolt broke off and the PO just welded it all closed? Maybe the bottom flange broke off during some rock-crawling and they had to fix it?
Or maybe it was a "cut" for ground clearance even! Not likely, but people do stuff like that.

Maybe it's just old. Never seen one and it's certainly true that '66 Broncos had some unique stuff.
But the good news is that your diff is a very desirable Dana Power-Lok (sp?) and is generally considered the most aggressive locking of all the old clutch-type limited-slip diffs.
Does it happen to have the 4.56 ratio option? Or is it 4.11 or something else? Was it a six-cylinder originally, or a V8?

I would not worry overmuch about the rust yet. Soak it in some Evapo-Rust, throw oil in it and run it.
But let's see some more close ups of the gear faces too while we're at it.

Thanks

Paul

 

[DirtDonk]

Wait, nevermind! Those teeth are gone!
Full rebuild time.

Sorry for not looking closer the first time.

Paul

 

[broncochevy]

If you look close in the pics you could see where there was a broken bolt or lease where it looks like it. In the 6 o’clock position. Since there’s no hole in the cover in that location, I assume it’s a broken bolt or where someone welded the broken Bolt and there was some imperfection left. 30s for some reason we’re notorious for breaking cover bolts. That’s my guess – broke a cover of old, welded in the bolt and ground smooth and welded said hole in cover.

 

[Ironlung1948]

Wait, nevermind! Those teeth are gone!
Full rebuild time.

Sorry for not looking closer the first time.

Paul

No problem ! and thank you for all the information. the front axel and housing is off the truck . Do you think buying a rebuilt kit and attempting to do it myself is reasonable option given that I dont have a press ? How do I tell what type of gear ratio I have and are the gear ratios interchangable ? I noticed on WH website there are a few options for the dana 30. thanks again!

 

[Broncobowsher]

Someone blew the front diff. Took the cover off and shoveled out all the broken bits. Then just put the cover back on. That is about what my 30 looked like when I blew mine up. The spider gears in the diff were also blown.

Before you go and spend too much on that axle consider that Ford even gave up on the 30 and started using the 44. The 30 is pretty weak in a Bronco. With light use they are fine, but as tire get bigger, trucks get heavier, and the HP goes up. The 44 is a better idea.

Used 30s are low value. Whole axles are well known to sell drum to drum for $100 ~ $250. You could have that much in parts. They show up all the time when you don't need them. Now that you need one, it will be tougher, its a law. If the 30 is still a good choice for you it is often easier and cheaper to get a whole axle. Just need to find a good one that has the right ratio.

 

[pipeline010]

piggyback with likely a real stupid question-

what's a good source truck for matching 44s to make as simple a swap as possible?

my front is very solid but with 33s it's not going to last forever. When I do pull the body I may put a 44 on if I can get a wall to wall with drums at a reasonable price.

 

[DirtDonk]

Do you think buying a rebuilt kit and attempting to do it myself is reasonable option given that I dont have a press?

I don't really think so, for most of us. If you're very handy, have all the usual tools, and are pretty good about figuring things out and have lots of patience, you can do it yourself. But it's a very fiddly job and most people (even pro mechanics!) end up letting the specialists do it.
But that's not to say you can't. Just that it's not a simple job when new parts are involved.

And keep in mind what Broncobowsher said. An entire assembly may come up right here in the classifieds near you. Someone even started a thread yesterday asking how much a 30 is worth. My answer was zero/free to about $150 bucks.
Unless, like he said, you really need one. In which case it's $400!

How do I tell what type of gear ratio I have

Simple enough now that it's open. Count the teeth on the ring gear, count the teeth on the pinion gear, and divide the small into the large.
For example, if it's got 41t and 10t gears (just as an example) you have a 4.10 ratio.
The three options on the Dana 30 from the factory were, if I remember, 3.50, 4.11 and 4.56 (six cylinder engines only I do believe).

And someone will correct me if I'm wrong, but I was not aware that Ford offered the Dana Power Lock (or however they spelled it) as the limited slip option.
However, over the years the models did change, so for all I know that was a factory option for your year.

and are the gear ratios interchangable?

Somewhat. There are two "carrier" sizes. The carrier is the differential itself, and what the ring gear is bolted to. In your case it's the Dana Power Lock.
There is a break somewhere between 3.70-ish and 3.90-ish (for the model 44 it's 3.73 and 3.92. Not sure if the 30 is the same.
So if your unit is currently a 4.09 or 4.10, or the 4.56, you can use other low gear ratios above the cutoff point. So you could change from 4.10 to 4.56 and vice versa no problem. But you could not install a 3.50 without changing the carrier.
For the 44 there are "thick cut" gears to compensate for this. But I'm not sure if they ever offered that for the 30 and if not you'd have to change the carrier.
This is not really a deal-breaker if your current carrier is thrashed and trashed. You'll need a new one anyway and can just choose which ratio you want to run.

what's a good source truck for matching 44s to make as simple a swap as possible?

There is no such vehicle.
The ONLY Dana differential that is a straight swap for a Bronco is one from another Early Bronco.
There are what are called "full width" swaps, where you use one from a full-size Ford truck of the same or similar vintage. But you either have to cut them down to match the Bronco, or run them full-width and deal with all the other stuff.
There are some advantages to this, but not for most of us.

If I was running 33's on a Dana 30 I'd be fine with it. There are a few members doing it here, and a few of them have used theirs relatively hard and have never had an issue.
Where the real issue is, is when you are stupid hard on your equipment.

In other words, if you never plan to go off-roading with it, or don't have a big engine and your right foot likes to play with the skinny pedal, your 30 is probably fine as long as you keep it maintained.
Just like any other part.

But hey, they're out there still if you think you need one. Just keep your eyes open for it, be patient and one will probably pop up.

Paul

 

[Broncobowsher]

Since you have the cover off, spin the ring gear around. There will be a bunch of numbers engraved in it. Look for two digits, colon, two more digits (xx:xx) Those two digits are the number of teeth on the pinion and ring gear. Divide the small number into the big number and you have the ratio. For 4.10 gears it will be "41:10" (or 10:41, I can't remember which one is first).

The last 30 I blew up had a date code of 1976, in a '69 Bronco. It had been rebuilt once before